From 84ed075e10cf1d25631a85ff6676b7cd7855ca1a Mon Sep 17 00:00:00 2001
From: teastep Shorewall consists of the following components: You may use the file /etc/shorewall/params file to set shell variables
- that you can then use in some of the other configuration files. It is suggested that variable names begin with an upper case letter to distinguish them from variables used internally
- within the Shorewall programs Example: Example (/etc/shorewall/interfaces record): The result will be the same as if the record had been written Variables may be used anywhere in the other configuration
- files. This file is used to define the network zones. There is one entry
- in /etc/shorewall/zones for each zone; Columns in an entry
-are: The /etc/shorewall/zones file released with Shorewall is as follows: You may add, delete and modify entries in the /etc/shorewall/zones file
- as desired so long as you have at least one zone defined. Warning 1: If you rename or delete a zone, you should perform "shorewall
- stop; shorewall start" to install the change rather than "shorewall
- restart". Shorewall consists of the following components: Warning 2: The order of entries in the /etc/shorewall/zones file is
- significant in some cases. This file is used to tell the firewall which of your firewall's network
- interfaces are connected to which zone. There will be one
-entry in /etc/shorewall/interfaces for each of your interfaces.
-Columns in an entry are: You may use the file /etc/shorewall/params file to set shell variables
+ that you can then use in some of the other configuration files. It is suggested that variable names begin with an upper case letter to distinguish them from variables used internally
+ within the Shorewall programs Example: Example (/etc/shorewall/interfaces record): The result will be the same as if the record had been written Variables may be used anywhere in the other configuration
+ files. This file is used to define the network zones. There is one entry
+ in /etc/shorewall/zones for each zone; Columns in an entry
+ are: The /etc/shorewall/zones file released with Shorewall is as follows: You may add, delete and modify entries in the /etc/shorewall/zones file
+ as desired so long as you have at least one zone defined. Warning 1: If you rename or delete a zone, you should perform "shorewall
+ stop; shorewall start" to install the change rather than "shorewall
+ restart". tcpflags (added in version 1.3.11) - This option causes Shorewall
-to make sanity checks on the header flags in TCP packets arriving on this
-interface. Checks include Null flags, SYN+FIN, SYN+RST and FIN+URG+PSH; these
-flag combinations are typically used for "silent" port scans. Packets failing
-these checks are logged according to the TCP_FLAGS_LOG_LEVEL option in /etc/shorewall/shorewall.conf and are disposed of according
- to the TCP_FLAGS_DISPOSITION option. This file is used to tell the firewall which of your firewall's network
+ interfaces are connected to which zone. There will be one
+entry in /etc/shorewall/interfaces for each of your interfaces.
+Columns in an entry are: tcpflags (added in version 1.3.11) - This option causes
+Shorewall to make sanity checks on the header flags in TCP packets arriving
+on this interface. Checks include Null flags, SYN+FIN, SYN+RST and FIN+URG+PSH;
+these flag combinations are typically used for "silent" port scans. Packets
+ failing these checks are logged according to the TCP_FLAGS_LOG_LEVEL option
+ in /etc/shorewall/shorewall.conf and are disposed of
+according to the TCP_FLAGS_DISPOSITION option.
-
-
-
-
-
+
+
+
-
-
-
-
-
-
- Shorewall 1.3 Reference
- This documentation is intended primarily for reference.
- Step-by-step instructions for configuring Shorewall in
-common setups may be found in the QuickStart Guides.
-
-
-Components
-
-
-
-
-
-
-
- /etc/shorewall/params
-
-
- NET_IF=eth0
-
-
NET_BCAST=130.252.100.255
NET_OPTIONS=blacklist,norfc1918 net $NET_IF $NET_BCAST $NET_OPTIONS
-
- net eth0 130.252.100.255 blacklist,norfc1918
-
- /etc/shorewall/zones
+ Shorewall 1.4 Reference
+
+
-
-
-
-
-
-
-
-
-
-
-
- ZONE
- DISPLAY
- COMMENTS
-
-
- net
- Net
- Internet
-
-
- loc
- Local
- Local networks
-
-
-
-
-
-
-
+
+
dmz
- DMZ
- Demilitarized zone
- This documentation is intended primarily for reference.
+ Step-by-step instructions for configuring Shorewall in
+ common setups may be found in the QuickStart Guides.
-
-Components
+
+
+ /etc/shorewall/interfaces
-
-
-
-
-
+
+
+
+
+ /etc/shorewall/params
+
+
+ NET_IF=eth0
+
+
NET_BCAST=130.252.100.255
NET_OPTIONS=blacklist,norfc1918 net $NET_IF $NET_BCAST $NET_OPTIONS
+
+ net eth0 130.252.100.255 blacklist,norfc1918
+
+ /etc/shorewall/zones
+
+
+
+
+
+
+
+
+
-
+
+ ZONE
+ DISPLAY
+ COMMENTS
+
+
+ net
+ Net
+ Internet
+
+
+ loc
+ Local
+ Local networks
+
+
-
+
+
+
+dmz
+ DMZ
+ Demilitarized zone
+
-
- blacklist - This option causes incoming packets on this
- interface to be checked against the Warning 2: The order of entries in the /etc/shorewall/zones file is
+ significant in some cases. /etc/shorewall/interfaces
+
+
+
+
+
+
+
+
+ blacklist - This option causes incoming packets on
+ this interface to be checked against the blacklist.
-
- dhcp - The interface is assigned an IP address
- via DHCP or is used by a DHCP server running on the firewall.
- The firewall will be configured to allow DHCP traffic to and
- from the interface even when the firewall is stopped. You may
- also wish to use this option if you have a static IP but you are
- on a LAN segment that has a lot of Laptops that use DHCP and you
- select the norfc1918 option (see below).
+ dhcp - The interface is assigned an IP
+address via DHCP or is used by a DHCP server running on
+the firewall. The firewall will be configured to allow DHCP
+traffic to and from the interface even when the firewall
+is stopped. You may also wish to use this option if you have a static
+IP but you are on a LAN segment that has a lot of Laptops that use
+DHCP and you select the norfc1918 option (see below).
noping - This option is deprecated and is not available
- when OLD_PING_HANDLING=No in /etc/shorewall/shorewall.conf. ICMP echo-request
- (ping) packets addressed to the firewall will be ignored by this
- interface.
-
- filterping - This option is deprecated
- and is not available when OLD_PING_HANDLING=No in /etc/shorewall/shorewall.conf.
- ICMP echo-request (ping) packets addressed to the firewall
-will be handled according to the /etc/shorewall/rules and /etc/shorewall/policy
- file. If the applicable policy is DROP or REJECT and you have
-supplied your own /etc/shorewall/icmpdef file then these 'ping' requests
- will be passed through the rules in that file before being dropped
- or rejected. If neither noping nor filterping
- is specified then the firewall will automatically ACCEPT these
-'ping' requests. If both noping and filterping
- are specified, filterping takes precedence.
norfc1918 - Packets arriving on this interface and that
+ have a source address that is reserved in RFC 1918 or in other
+ RFCs will be dropped after being optionally logged. If packet mangling is enabled in /etc/shorewall/shorewall.conf
+ , then packets arriving on this interface that have a destination
+ address that is reserved by one of these RFCs will also be logged
+ and dropped.
+
+ Addresses blocked by the standard rfc1918 file include those
+ addresses reserved by RFC1918 plus other ranges reserved by the
+ IANA or by other RFCs.
routestopped - Beginning with Shorewall 1.3.4, this option - is deprecated in favor of the /etc/shorewall/routestopped - file. When the firewall is stopped, traffic to and from - this interface will be accepted and routing will occur between -this interface and other routestopped interfaces.
+ +Beware that as IPv4 addresses become in increasingly short supply, + ISPs are beginning to use RFC 1918 addresses within their +own infrastructure. Also, many cable and DSL "modems" have an +RFC 1918 address that can be used through a web browser for management + and monitoring functions. If you want to specify norfc1918 + on your external interface but need to allow access to certain + addresses from the above list, see FAQ 14.
- - norfc1918 - Packets arriving on this interface and that
- have a source address that is reserved in RFC 1918 or in other
- RFCs will be dropped after being optionally logged. If packet mangling is enabled in /etc/shorewall/shorewall.conf
- , then packets arriving on this interface that have a destination
- address that is reserved by one of these RFCs will also be logged
- and dropped.
-
- Addresses blocked by the standard rfc1918 file include those
- addresses reserved by RFC1918 plus other ranges reserved by the
- IANA or by other RFCs.
Beware that as IPv4 addresses become in increasingly short supply, - ISPs are beginning to use RFC 1918 addresses within their -own infrastructure. Also, many cable and DSL "modems" have -an RFC 1918 address that can be used through a web browser for -management and monitoring functions. If you want to specify norfc1918 - on your external interface but need to allow access to certain -addresses from the above list, see FAQ 14.
- - - -routefilter - Invoke the Kernel's route filtering - (anti-spoofing) facility on this interface. The kernel - will reject any packets incoming on this interface that have -a source address that would be routed outbound through another - interface on the firewall. Warning: - If you specify this option for an interface then the + +
routefilter - Invoke the Kernel's route filtering + (anti-spoofing) facility on this interface. The kernel + will reject any packets incoming on this interface that have a +source address that would be routed outbound through another + interface on the firewall. Warning: + If you specify this option for an interface then the interface must be up prior to starting the firewall.
- -multi - The interface has multiple addresses and - you want to be able to route between them. Example: you - have two addresses on your single local interface eth1, one - each in subnets 192.168.1.0/24 and 192.168.2.0/24 and you want to - route between these subnets. Because you only have one interface - in the local zone, Shorewall won't normally create a rule to forward - packets from eth1 to eth1. Adding "multi" to the entry for eth1 - will cause Shorewall to create the loc2loc chain and the appropriate - forwarding rule.
+ + dropunclean - Packets from this interface that
+ are selected by the 'unclean' match target in iptables will
+ be optionally logged and then
+dropped. Warning: This feature
+ requires that UNCLEAN match support be configured in
+your kernel, either in the kernel itself or as a module.
+UNCLEAN support is broken in some versions of the
+kernel but appears to work ok in 2.4.17-rc1.
+
+ Update 12/17/2001: The
+ unclean match patch from 2.4.17-rc1 is available
+ for download. I am currently running
+ this patch applied to kernel 2.4.16.
dropunclean - Packets from this interface that
- are selected by the 'unclean' match target in iptables will
- be optionally logged and then dropped.
- Warning: This feature
- requires that UNCLEAN match support be configured in your
- kernel, either in the kernel itself or as a module. UNCLEAN
- support is broken in some versions of the kernel
-but appears to work ok in 2.4.17-rc1.
-
- Update 12/17/2001: The
- unclean match patch from 2.4.17-rc1 is available
- for download. I am currently running this
- patch applied to kernel 2.4.16.
Update 12/20/2001: I've + seen a number of tcp connection requests + with OPT (020405B40000080A...) being + dropped in the badpkt chain. This appears to be + a bug in the remote TCP stack whereby it is 8-byte aligning + a timestamp (TCP option 8) but rather than padding +with 0x01 it is padding with 0x00. It's a tough call +whether to deny people access to your servers because + of this rather minor bug in their networking software. + If you wish to disable the check that causes these + connections to be dropped, here's + a kernel patch against 2.4.17-rc2.
- -Update 12/20/2001: I've - seen a number of tcp connection requests with - OPT (020405B40000080A...) being dropped - in the badpkt chain. This appears to be - a bug in the remote TCP stack whereby it is 8-byte aligning - a timestamp (TCP option 8) but rather than padding with 0x01 - it is padding with 0x00. It's a tough call whether -to deny people access to your servers because of this - rather minor bug in their networking software. If - you wish to disable the check that causes these -connections to be dropped, here's - a kernel patch against 2.4.17-rc2.
+ +logunclean - This option works like dropunclean + with the exception that packets selected + by the 'unclean' match target in iptables +are logged but not dropped. The +level at which the packets are logged is determined by + the setting of LOGUNCLEAN + and if LOGUNCLEAN has not been set, "info" is assumed.
- -logunclean - This option works like dropunclean - with the exception that packets selected by - the 'unclean' match target in iptables are logged - but not dropped. The level at which - the packets are logged is determined by the setting - of LOGUNCLEAN and if - LOGUNCLEAN has not been set, "info" is assumed.
- - - -proxyarp (Added in version 1.3.5) - This option
- causes Shorewall to set /proc/sys/net/ipv4/conf/<interface>/proxy_arp
- and is used when implementing Proxy ARP
-Sub-netting as described at
-
- http://www.tldp.org/HOWTO/mini/Proxy-ARP-Subnet/. Do
- not set this option if you are implementing Proxy
-ARP through entries in
- /etc/shorewall/proxyarp.
-
- maclist (Added in version 1.3.10) - If this
- option is specified, all connection requests from this interface
-are subject to MAC Verification.
-May only be specified for ethernet interfaces.
proxyarp (Added in version 1.3.5) - This option
+ causes Shorewall to set /proc/sys/net/ipv4/conf/<interface>/proxy_arp
+ and is used when implementing Proxy ARP
+Sub-netting as described at
+
+ http://www.tldp.org/HOWTO/mini/Proxy-ARP-Subnet/. Do
+ not set this option if you are implementing Proxy
+ARP through entries in
+ /etc/shorewall/proxyarp.
+
+ maclist (Added in version 1.3.10) - If
+this option is specified, all connection requests from this interface
+ are subject to MAC Verification.
+ May only be specified for ethernet interfaces.
My recommendations concerning options:
-
- -
Example 1: You have a conventional firewall setup in which eth0 connects - to a Cable or DSL modem and eth1 connects to your local network - and eth0 gets its IP address via DHCP. You want to check all -packets entering from the internet against the -black list. Your /etc/shorewall/interfaces file - would be as follows:
+ +Example 1: You have a conventional firewall setup in which eth0 connects + to a Cable or DSL modem and eth1 connects to your local network + and eth0 gets its IP address via DHCP. You want to check all +packets entering from the internet against the +black list. Your /etc/shorewall/interfaces file + would be as follows:
- -- -- - -- -
-- -ZONE -INTERFACE -BROADCAST -OPTIONS -- -net -eth0 -detect -dhcp,norfc1918,blacklist -- - - - - - - -loc -eth1 -detect --
-
Example 2: You have a standalone dialup GNU/Linux System. Your /etc/shorewall/interfaces - file would be:
- - +- +- - -- -
-- -ZONE -INTERFACE -BROADCAST -OPTIONS -- + +net -ppp0 - --
--
-+ +ZONE +INTERFACE +BROADCAST +OPTIONS ++ +net +eth0 +detect +dhcp,norfc1918,blacklist ++ - - - - -loc +eth1 +detect ++
+
Example 3: You have local interface eth1 with two IP - addresses - 192.168.1.1/24 and 192.168.12.1/24
- - -- -- - -- -
-- -ZONE -INTERFACE -BROADCAST -OPTIONS -- - - - - - - -loc -eth1 - -192.168.1.255,192.168.12.255 --
-
For most applications, specifying zones entirely in terms of network - interfaces is sufficient. There may be times though where you need to -define a zone to be a more general collection of hosts. This is the purpose -of the /etc/shorewall/hosts file.
- - -WARNING: 90% of - Shorewall users don't need to put entries in this file and - 80% of those who try to add such entries do it wrong. - Unless you are ABSOLUTELY SURE that you need entries in - this file, don't touch it.
- - -Columns in this file are:
- - -- --+ -
- An IP address (example - eth1:192.168.1.3)
+ + +
Example 2: You have a standalone dialup GNU/Linux System. Your /etc/shorewall/interfaces + file would be:
+ + ++ ++ + ++ +
++ +ZONE +INTERFACE +BROADCAST +OPTIONS ++ - - + + + + + +net +ppp0 + ++
++
+
Example 3: You have local interface eth1 with two IP + addresses - 192.168.1.1/24 and 192.168.12.1/24
+ + ++ ++ + ++ +
++ +ZONE +INTERFACE +BROADCAST +OPTIONS ++ - -loc +eth1 + +192.168.1.255,192.168.12.255 ++
+The interface name much match an entry in /etc/shorewall/interfaces.
- - + + + +
For most applications, specifying zones entirely in terms of network + interfaces is sufficient. There may be times though where you need to define +a zone to be a more general collection of hosts. This is the purpose of +the /etc/shorewall/hosts file.
+ + +WARNING: 90% of +Shorewall users don't need to put entries in this file and + 80% of those who try to add such entries do it wrong. + Unless you are ABSOLUTELY SURE that you need entries in + this file, don't touch it.
+ + +Columns in this file are:
+ +- - -- - -routestopped - Beginning with Shorewall - 1.3.4, this option is deprecated in favor of the - /etc/shorewall/routestopped - file. When the firewall is stopped, traffic to and from - this host (these hosts) will be accepted and routing will - occur between this host and other routestopped interfaces - and hosts.
-
-
- maclist - Added in version 1.3.10. If specified, - connection requests from the hosts specified in this entry are subject - to MAC Verification. This option is only - valid for ethernet interfaces.
-
If you don't define any hosts for a zone, the hosts in the zone default - to i0:0.0.0.0/0 , i1:0.0.0.0/0, ... where i0, i1, ... are -the interfaces to the zone.
- - -Note 1: You probably -DON'T want to specify any hosts for your internet zone since the hosts -that you specify will be the only ones that you will be able to access -without adding additional rules.
- - -Note 2: - The setting of the MERGE_HOSTS variable - in /etc/shorewall/shorewall.conf - has an important effect on how the -host file is processed. Please read the -description of that variable carefully.
- - -Example:
- - -Your local interface is eth1 and you have two groups of local hosts that - you want to make into separate zones:
- - -Your /etc/shorewall/interfaces file might look like:
- - -- -+- -
-- -ZONE -INTERFACE -BROADCAST -OPTIONS -- -net -eth0 -detect -dhcp,norfc1918 -- - - - - - +- -eth1 -detect --
--
The '-' in the ZONE column for eth1 tells Shorewall that eth1 interfaces - to multiple zones.
+Your /etc/shorewall/hosts file might look like:
+- - -- - -- -
-- -ZONE -HOST(S) -OPTIONS -- -loc1 -eth1:192.168.1.0/25 --
-- - - - - - - - -loc2 -eth1:192.168.1.128/25 -routestopped -
Hosts in 'loc2' can communicate with the firewall while Shorewall is - stopped -- those in 'loc1' cannot.
- - -The /etc/shorewall/interfaces and /etc/shorewall/hosts file allow - you to define nested or overlapping zones. Such overlapping/nested zones - are allowed and Shorewall processes zones in the order that - they appear in the /etc/shorewall/zones file. So if you have nested - zones, you want the sub-zone to appear before the super-zone -and in the case of overlapping zones, the rules that will apply -to hosts that belong to both zones is determined by which zone appears -first in /etc/shorewall/zones.
- - -Hosts that belong to more than one zone may be managed by the rules - of all of those zones. This is done through use of the special - CONTINUE policy described below.
- - -This file is used to describe the firewall policy regarding establishment - of connections. Connection establishment is described in terms - of clients who initiate connections and servers who - receive those connection requests. Policies defined in /etc/shorewall/policy - describe which zones are allowed to establish connections with - other zones.
- - - -Policies established in /etc/shorewall/policy can be viewed as default - policies. If no rule in /etc/shorewall/rules applies to a -particular connection request then the policy from /etc/shorewall/policy - is applied.
- - - -Four policies are defined:
-For each policy specified in /etc/shorewall/policy, you can indicate - that you want a message sent to your system log each time -that the policy is applied.
- - -Entries in /etc/shorewall/policy have four columns as follows:
- - -In the SOURCE and DEST columns, you can enter "all" to indicate all - zones.
- - -The policy file installed by default is as follows:
- - -- - -- - - -- -
-- -SOURCE -DEST -POLICY -LOG LEVEL -LIMIT:BURST -- -loc -net -ACCEPT -- -
--
-- -net -all -DROP -info --
-- + + +all -all -REJECT -info --
-The interface name much match an entry in /etc/shorewall/interfaces.
+ - - - -
This table may be interpreted as follows:
- -WARNING:
+ +- -- -The firewall script processes the - /etc/shorewall/policy file from top to bottom and uses -the first applicable policy that it finds. For example, -in the following policy file, the policy for (loc, loc) connections -would be ACCEPT as specified in the first entry even though the -third entry in the file specifies REJECT.
+ +maclist - Added in version 1.3.10. If specified, connection + requests from the hosts specified in this entry are subject to + MAC Verification. This option is only + valid for ethernet interfaces.
+
+
- -+ +- -
-- -SOURCE -DEST -POLICY -LOG LEVEL -LIMIT:BURST -- + +loc -all -ACCEPT --
--
-If you don't define any hosts for a zone, the hosts in the zone default + to i0:0.0.0.0/0 , i1:0.0.0.0/0, ... where i0, i1, ... are +the interfaces to the zone.
-- -net -all -DROP -info --
-- + +loc -loc -REJECT -info --
-Note: You probably DON'T +want to specify any hosts for your internet zone since the hosts that +you specify will be the only ones that you will be able to access without +adding additional rules.
- - + +Example:
- -
Your local interface is eth1 and you have two groups of local hosts that + you want to make into separate zones:
- -Where zones are nested or overlapping , the - CONTINUE policy allows hosts that are within multiple zones to - be managed under the rules of all of these zones. Let's look at -an example:
+ +Your /etc/shorewall/interfaces file might look like:
- -/etc/shorewall/zones:
- - -- -- - -- -
-- -ZONE -DISPLAY -COMMENTS -- -sam -Sam -Sam's system at home -- -net -Internet -The Internet -- - - - - - - - -loc -Loc -Local Network -
/etc/shorewall/interfaces:
- - ++ + +- -
+- -ZONE -INTERFACE -BROADCAST -OPTIONS -- -- -eth0 -detect -dhcp,norfc1918 -- + +loc -eth1 -detect -routestopped -+ +ZONE +INTERFACE +BROADCAST +OPTIONS ++ +net +eth0 +detect +dhcp,norfc1918 ++ + + + + + + + +- +eth1 +detect ++
+
The '-' in the ZONE column for eth1 tells Shorewall that eth1 interfaces + to multiple zones.
+ + +Your /etc/shorewall/hosts file might look like:
+ + ++ + ++ + + ++ +
++ +ZONE +HOST(S) +OPTIONS ++ +loc1 +eth1:192.168.1.0/25 ++
++ + + +loc2 +eth1:192.168.1.128/25 ++
+
Hosts in 'loc2' can communicate with the firewall while Shorewall is + stopped -- those in 'loc1' cannot.
+ + + +The /etc/shorewall/interfaces and /etc/shorewall/hosts file allow +you to define nested or overlapping zones. Such overlapping/nested zones + are allowed and Shorewall processes zones in the order that + they appear in the /etc/shorewall/zones file. So if you have nested + zones, you want the sub-zone to appear before the super-zone +and in the case of overlapping zones, the rules that will apply +to hosts that belong to both zones is determined by which zone appears + first in /etc/shorewall/zones.
+ + + +Hosts that belong to more than one zone may be managed by the rules + of all of those zones. This is done through use of the special + CONTINUE policy described below.
+ + + +This file is used to describe the firewall policy regarding establishment + of connections. Connection establishment is described in terms + of clients who initiate connections and servers who + receive those connection requests. Policies defined in /etc/shorewall/policy + describe which zones are allowed to establish connections with + other zones.
+ + + +Policies established in /etc/shorewall/policy can be viewed as default + policies. If no rule in /etc/shorewall/rules applies to a +particular connection request then the policy from /etc/shorewall/policy + is applied.
+ + + +Four policies are defined:
+ + +For each policy specified in /etc/shorewall/policy, you can indicate + that you want a message sent to your system log each time +that the policy is applied.
+ + + +Entries in /etc/shorewall/policy have four columns as follows:
+ + + +In the SOURCE and DEST columns, you can enter "all" to indicate all + zones.
+ + + +The policy file installed by default is as follows:
+ + + ++ + ++ + + + ++ +
-+ +SOURCE +DEST +POLICY +LOG LEVEL +LIMIT:BURST ++ +loc +net +ACCEPT ++ +
++
++ +net +all +DROP +info ++
++ - + - +all +all +REJECT +info ++
+
This table may be interpreted as follows:
+ + +/etc/shorewall/hosts:
+WARNING:
-- +-The firewall script processes the + /etc/shorewall/policy file from top to bottom and uses +the first applicable policy that it finds. For example, in +the following policy file, the policy for (loc, loc) connections +would be ACCEPT as specified in the first entry even though the third +entry in the file specifies REJECT.
+ + +++- -
-- -ZONE -HOST(S) -OPTIONS -- + +net -eth0:0.0.0.0/0 --
-+ +SOURCE +DEST +POLICY +LOG LEVEL +LIMIT:BURST ++ -loc +all +ACCEPT ++
++
+- +sam -eth0:206.191.149.197 -routestopped -+ +net +all +DROP +info ++
++ - + - +loc +loc +REJECT +info ++
+
Note that Sam's home system is a member of both the sam zone - and the net zone - and as described above , that means that -sam must be listed before net in /etc/shorewall/zones.
+/etc/shorewall/policy:
+Where zones are nested or overlapping , the + CONTINUE policy allows hosts that are within multiple zones to + be managed under the rules of all of these zones. Let's look at + an example:
-+-/etc/shorewall/zones:
+ + ++- - -
-- -SOURCE -DEST -POLICY -LOG LEVEL -- - -loc -net -ACCEPT --
-- - -sam -all -CONTINUE --
-- -net -all -DROP -info -- + +all -all -REJECT -info -+ +ZONE +DISPLAY +COMMENTS ++ +sam +Sam +Sam's system at home ++ +net +Internet +The Internet ++ - + - +loc +Loc +Local Network +
The second entry above says that when Sam is the client, connection - requests should first be process under rules where the source - zone is sam and if there is no match then the connection -request should be treated under rules where the source zone is -net. It is important that this policy be listed BEFORE -the next policy (net to all).
+/etc/shorewall/interfaces:
-Partial /etc/shorewall/rules:
- - -- +-++- - -
-- -ACTION -SOURCE -DEST -PROTO -DEST -
- PORT(S)SOURCE -
- PORT(S)ORIGINAL - -
- DEST- - -... --
--
--
--
--
--
-- -DNAT -sam -loc:192.168.1.3 -tcp -ssh -- --
-- -DNAT -net -loc:192.168.1.5 -tcp -www -- --
-- + +... --
--
--
--
--
--
-+ +ZONE +INTERFACE +BROADCAST +OPTIONS ++ +- +eth0 +detect +dhcp,norfc1918 ++ - - + +loc +eth1 +detect ++
+
Given these two rules, Sam can connect to the firewall's internet interface - with ssh and the connection request will be forwarded to 192.168.1.3. - Like all hosts in the net zone, Sam can connect to the -firewall's internet interface on TCP port 80 and the connection -request will be forwarded to 192.168.1.5. The order of the rules -is not significant.
+/etc/shorewall/hosts:
- -Sometimes it is necessary to suppress port forwarding - for a sub-zone. For example, suppose that all hosts can SSH - to the firewall and be forwarded to 192.168.1.5 EXCEPT Sam. When - Sam connects to the firewall's external IP, he should be connected - to the firewall itself. Because of the way that Netfilter is constructed, - this requires two rules as follows:
- - -- -- -- - - + +
++ + +- -
+- + -ACTION -SOURCE -DEST -PROTO -DEST -
- PORT(S)SOURCE -
- PORT(S)ORIGINAL -
- DEST- --
--
--
--
--
--
--
-- ... --
--
--
--
--
-+
-+ +ZONE +HOST(S) +OPTIONS ++ + +net +eth0:0.0.0.0/0 ++
++ + + + + + + + + +sam +eth0:206.191.149.197 ++
+Note that Sam's home system is a member of both the sam zone + and the net zone + and as described above , that means that + sam must be listed before net in /etc/shorewall/zones.
+ + +/etc/shorewall/policy:
+ + ++ ++ + ++ + +
++ +SOURCE +DEST +POLICY +LOG LEVEL ++ + +loc +net +ACCEPT ++
++ + +sam +all +CONTINUE ++
++ +net +all +DROP +info ++ + + + + + + + + + +all +all +REJECT +info +The second entry above says that when Sam is the client, connection + requests should first be process under rules where the source + zone is sam and if there is no match then the connection +request should be treated under rules where the source zone is net. + It is important that this policy be listed BEFORE the next policy + (net to all).
+ + +Partial /etc/shorewall/rules:
+ + ++ +++ + +
-+ -ACTION +SOURCE +DEST +PROTO +DEST +
+ PORT(S)SOURCE +
+ PORT(S)ORIGINAL
+ DEST- -DNAT -sam -fw -tcp -ssh -- --
-- -DNAT -net!sam -loc:192.168.1.3 -tcp -ssh -- --
-- +... --
--
--
--
--
--
-+ + +... ++
++
++
++
++
++
++ +DNAT +sam +loc:192.168.1.3 +tcp +ssh +- ++
++ +DNAT +net +loc:192.168.1.5 +tcp +www +- ++
++ - - - + + + + + +... ++
++
++
++
++
++
+
The first rule allows Sam SSH - access to the firewall. The second - rule says that any clients from the - net zone with the exception of those - in the 'sam' zone should have their - connection port forwarded to - 192.168.1.3. If you need to exclude - more than one zone in this way, - you can list the -zones separated by + +
Given these two rules, Sam can connect to the firewall's internet interface + with ssh and the connection request will be forwarded to 192.168.1.3. + Like all hosts in the net zone, Sam can connect to the + firewall's internet interface on TCP port 80 and the connection + request will be forwarded to 192.168.1.5. The order of the rules + is not significant.
+ + +Sometimes it is necessary to suppress port forwarding + for a sub-zone. For example, suppose that all hosts can SSH + to the firewall and be forwarded to 192.168.1.5 EXCEPT Sam. When + Sam connects to the firewall's external IP, he should be connected + to the firewall itself. Because of the way that Netfilter is constructed, + this requires two rules as follows:
+ + ++ ++ + ++ + + +
+ +
++ + +ACTION +SOURCE +DEST +PROTO +DEST +
+ PORT(S)SOURCE +
+ PORT(S)ORIGINAL +
+ DEST+ ++
++
++
++
++
++
++
++ +... ++
++
++
++
++
++ +
++ +DNAT +sam +fw +tcp +ssh +- ++
++ +DNAT +net!sam +loc:192.168.1.3 +tcp +ssh +- ++
++ + + + + + + + +... ++
++
++
++
++
++
+
The first rule allows Sam SSH + access to the firewall. The second + rule says that any clients from the + net zone with the exception of those + in the 'sam' zone should have their + connection port forwarded to + 192.168.1.3. If you need to exclude + more than one zone in this way, + you can list the + zones separated by commas (e.g., net!sam,joe,fred). This technique also may be used when the ACTION is REDIRECT.
- -The /etc/shorewall/rules file defines exceptions to the policies established
- in the /etc/shorewall/policy file. There is one entry in /etc/shorewall/rules
- for each of these rules.
-
Shorewall automatically enables firewall->firewall traffic over the
- loopback interface (lo) -- that traffic cannot be regulated using
-rules and any rule that tries to regulate such traffic will generate
-a warning and will be ignored.
-
The /etc/shorewall/rules file defines exceptions to the policies established
+ in the /etc/shorewall/policy file. There is one entry in /etc/shorewall/rules
+ for each of these rules.
+
Shorewall automatically enables firewall->firewall traffic over the
+ loopback interface (lo) -- that traffic cannot be regulated using
+ rules and any rule that tries to regulate such traffic will generate
+ a warning and will be ignored.
+
Entries in the file have the following columns:
- +The ACTION may optionally be followed by ":" and a syslog level (example: REJECT:info).
-This causes the packet to be logged at the specified level prior
-to being processed according to the specified ACTION.
-
- The use of DNAT or REDIRECT requires that you
-have NAT enabled.
-
Example 1. You wish to forward all - ssh connection requests from the internet to local system + name="PortForward"> Example 1. You wish to forward all + ssh connection requests from the internet to local system 192.168.1.3.
- -- -- - -- - -
-- -ACTION -SOURCE -DEST -PROTO -DEST -
- PORT(S)SOURCE -
- PORT(S)ORIGINAL - -
- DEST- - - - - - - - - - -DNAT -net -loc:192.168.1.3 -tcp -ssh --
--
-
Example 2. You want to redirect all local www connection requests - EXCEPT those -to your own http server - (206.124.146.177) to a Squid - transparent proxy running on the firewall and -listening on port 3128. Squid will of course require access to -remote web servers. This example shows yet - another use for the ORIGINAL - DEST column; here, connection - requests that were NOT - - (notice the "!") originally - destined to 206.124.146.177 - are redirected to local - port 3128.
- -- +-++- + -
-- ACTION -SOURCE -DEST -PROTO -DEST -
- PORT(S)SOURCE -
- PORT(S)ORIGINAL +
- DEST+ -ACTION +SOURCE +DEST +PROTO +DEST +
+ PORT(S)SOURCE +
+ PORT(S)ORIGINAL -
+ DEST- -REDIRECT -loc -3128 -tcp -www -- -
-!206.124.146.177 -- + +ACCEPT -fw -net -tcp -www --
--
-+ - - + + - +DNAT +net +loc:192.168.1.3 +tcp +ssh ++
++
+
Example 3. You want to run a web server at 155.186.235.222 in -your DMZ and have it accessible remotely and locally. the DMZ is managed - by Proxy ARP or by classical sub-netting.
+Example 2. You want to redirect all local www connection requests + EXCEPT those + to your own http server + (206.124.146.177) to a Squid + transparent proxy running on the firewall and + listening on port 3128. Squid will of course require access to +remote web servers. This example shows yet + another use for the ORIGINAL + DEST column; here, connection + requests that were NOT + + (notice the "!") originally + destined to 206.124.146.177 + are redirected to local + port 3128.
-- +-++- + -
-- ACTION -SOURCE -DEST -PROTO -DEST -
- PORT(S)SOURCE -
- PORT(S)ORIGINAL +
- DEST+ -ACTION +SOURCE +DEST +PROTO +DEST +
+ PORT(S)SOURCE +
+ PORT(S)ORIGINAL -
+ DEST- - -ACCEPT -net -dmz:155.186.235.222 -tcp -www -- --
-- + +ACCEPT -loc -dmz:155.186.235.222 -tcp -www --
--
-+ +REDIRECT +loc +3128 +tcp +www +- +
+!206.124.146.177 ++ - - + + - +ACCEPT +fw +net +tcp +www ++
++
+
Example 4. You want to run wu-ftpd on 192.168.2.2 in your masqueraded - DMZ. Your internet interface address is 155.186.235.151 and - you want the FTP server to be accessible from the internet in -addition to the local 192.168.1.0/24 and dmz 192.168.2.0/24 -subnetworks. Note that since the server is in the 192.168.2.0/24 subnetwork, +
Example 3. You want to run a web server at 155.186.235.222 in your + DMZ and have it accessible remotely and locally. the DMZ is managed + by Proxy ARP or by classical sub-netting.
+ + ++ ++ + ++ + +
++ +ACTION +SOURCE +DEST +PROTO +DEST +
+ PORT(S)SOURCE +
+ PORT(S)ORIGINAL + +
+ DEST+ + +ACCEPT +net +dmz:155.186.235.222 +tcp +www +- ++
++ + + + + + + + + + +ACCEPT +loc +dmz:155.186.235.222 +tcp +www ++
++
+
Example 4. You want to run wu-ftpd on 192.168.2.2 in your masqueraded
+ DMZ. Your internet interface address is 155.186.235.151 and
+ you want the FTP server to be accessible from the internet in
+ addition to the local 192.168.1.0/24 and dmz 192.168.2.0/24
+ subnetworks. Note that since the server is in the 192.168.2.0/24 subnetwork,
we can assume that access to the server from that subnet will not
involve the firewall (but see FAQ 2).
Note that unless you
@@ -1772,332 +1742,334 @@ Note that unless you
cannot leave it blank in the
second rule though because
then all ftp connections
- originating in the
+ originating in the
local subnet 192.168.1.0/24
- would be sent to 192.168.2.2
- regardless of
-the site that the
-user was trying to
- connect to. That is
- clearly not what you want
-
- .
- + face="Century Gothic, Arial, Helvetica"> +- - - -- + -
-- ACTION -SOURCE -DEST -PROTO -DEST -
- PORT(S)SOURCE -
- PORT(S)ORIGINAL +
- DEST+ -ACTION +SOURCE +DEST +PROTO +DEST +
+ PORT(S)SOURCE +
+ PORT(S)ORIGINAL -
+ DEST- -DNAT -net -dmz:192.168.2.2 -tcp -ftp --
--
-- + +DNAT -loc:192.168.1.0/24 -dmz:192.168.2.2 -tcp -ftp -- -155.186.235.151 -+ +DNAT +net +dmz:192.168.2.2 +tcp +ftp ++
++
++ - - + + - +DNAT +loc:192.168.1.0/24 +dmz:192.168.2.2 +tcp +ftp +- +155.186.235.151 +
If you are running wu-ftpd, you should restrict the range of passive - in your /etc/ftpaccess file. I only need a few simultaneous FTP sessions - so I use port range 65500-65535. In /etc/ftpaccess, this entry - is appropriate:
- - - -- - - -- - - - -passive ports 0.0.0.0/0 65500 65534
-
If you are running pure-ftpd, you would include "-p 65500:65534" on - the pure-ftpd runline.
- - - - -The important point here is to ensure that the port range used for FTP - passive connections is unique and will not overlap with any -usage on the firewall system.
- - - - -Example 5. You - wish to allow unlimited - DMZ access to the host - with MAC address - 02:00:08:E3:FA:55.
- - - - -- -- - - Example -6. You wish to allow access to the SMTP server in your DMZ from -all zones.- - -
-- -ACTION -SOURCE -DEST -PROTO -DEST -
- PORT(S)SOURCE -
- PORT(S)ORIGINAL - -
- DEST- - - - - - - - -ACCEPT -loc:~02-00-08-E3-FA-55 -dmz -all --
--
--
-
-- Example 7 (For advanced users running Shorewall version 1.3.13 - or later). From the internet, you with to forward tcp port 25 directed - to 192.0.2.178 and 192.0.2.179 to host 192.0.2.177 in your DMZ. You -also want to allow access from the internet directly to tcp port 25 on -192.0.2.177.- -
-- -ACTION -
-SOURCE -
-DEST -
-PROTO -
-DEST -
- PORT(S)
-SOURCE -
- PORT(S)
-ORIGINAL -
- DEST
-- - - - -ACCEPT -
-all -
-dmz -
-tcp -
-25 -
--
--
-
- Note: When 'all' is used as a source or destination, intra-zone - traffic is not affected. In this example, if there were two DMZ interfaces - then the above rule would NOT enable SMTP traffic between hosts on -these interfaces.
-
-- Using "DNAT-" rather than "DNAT" avoids two extra copies of the - third rule from being generated.- -
-- -ACTION -
-SOURCE -
-DEST -
-PROTO -
-DEST -
- PORT(S)
-SOURCE -
- PORT(S)
-ORIGINAL -
- DEST
-- -DNAT- -
-net -
-dmz:192.0.2.177 -
-tcp -
-25 -
-0 -
-192.0.2.178 -
-- -DNAT- -
-net -
-dmz:192.0.2.177 -
-tcp -
-25 -
-0 -
-192.0.2.179 -
-- - - - -ACCEPT -
-net -
-dmz:192.0.2.177 -
-tcp -
-25 -
--
--
-
Look here for information on other services. -
+ -If you are running wu-ftpd, you should restrict the range of passive + in your /etc/ftpaccess file. I only need a few simultaneous FTP sessions + so I use port range 65500-65535. In /etc/ftpaccess, this entry + is appropriate:
-Shorewall allows - definition of rules that - apply between all zones. - By default, these rules - are defined in the file - /etc/shorewall/common.def - but may be modified to - suit individual - requirements. Rather - than -modify /etc/shorewall/common.def, - you -should copy that - file to - /etc/shorewall/common - and modify that file.
++ + + +- -passive ports 0.0.0.0/0 65500 65534
+
The /etc/shorewall/common - file -is expected to + +
If you are running pure-ftpd, you would include "-p 65500:65534" on + the pure-ftpd runline.
+ + + + +The important point here is to ensure that the port range used for FTP + passive connections is unique and will not overlap with any + usage on the firewall system.
+ + + + +Example 5. You + wish to allow unlimited + DMZ access to the host + with MAC address + 02:00:08:E3:FA:55.
+ + + + ++ ++ + + Example + 6. You wish to allow access to the SMTP server in your DMZ from + all zones.+ + +
++ +ACTION +SOURCE +DEST +PROTO +DEST +
+ PORT(S)SOURCE +
+ PORT(S)ORIGINAL + +
+ DEST+ + + + + + + + +ACCEPT +loc:~02-00-08-E3-FA-55 +dmz +all ++
++
++
+
++ Example 7 (For advanced users running Shorewall version +1.3.13 or later). From the internet, you with to forward tcp port +25 directed to 192.0.2.178 and 192.0.2.179 to host 192.0.2.177 in your +DMZ. You also want to allow access from the internet directly to tcp +port 25 on 192.0.2.177.+ +
++ +ACTION +
+SOURCE +
+DEST +
+PROTO +
+DEST +
+ PORT(S)
+SOURCE +
+ PORT(S)
+ORIGINAL +
+ DEST
++ + + + +ACCEPT +
+all +
+dmz +
+tcp +
+25 +
++
++
+
+ Note: When 'all' is used as a source or destination, +intra-zone traffic is not affected. In this example, if there were +two DMZ interfaces then the above rule would NOT enable SMTP traffic +between hosts on these interfaces.
+
++ Using "DNAT-" rather than "DNAT" avoids two extra copies of + the third rule from being generated.+ +
++ +ACTION +
+SOURCE +
+DEST +
+PROTO +
+DEST +
+ PORT(S)
+SOURCE +
+ PORT(S)
+ORIGINAL +
+ DEST
++ +DNAT- +
+net +
+dmz:192.0.2.177 +
+tcp +
+25 +
+0 +
+192.0.2.178 +
++ +DNAT- +
+net +
+dmz:192.0.2.177 +
+tcp +
+25 +
+0 +
+192.0.2.179 +
++ + + + +ACCEPT +
+net +
+dmz:192.0.2.177 +
+tcp +
+25 +
++
++
+
Look here for information on other services. +
+ + + + +Shorewall allows + definition of rules that + apply between all zones. + By default, these rules + are defined in the file + /etc/shorewall/common.def + but may be modified to + suit individual + requirements. Rather + than + modify /etc/shorewall/common.def, + you +should copy that + file to + /etc/shorewall/common + and modify that file.
+ + + + +The /etc/shorewall/common + file + is expected to contain iptables commands; rather than running iptables directly, you should run - it indirectly using the - Shorewall function - 'run_iptables'. + it indirectly using the + Shorewall function + 'run_iptables'. That way, if iptables encounters an error, the firewall will be safely @@ -2105,136 +2077,139 @@ is expected to - -
The /etc/shorewall/masq file is used to define classical IP Masquerading - and Source Network Address Translation (SNAT). There is one -entry in the file for each subnet that you want to masquerade. + +
The /etc/shorewall/masq file is used to define classical IP Masquerading + and Source Network Address Translation (SNAT). There is one +entry in the file for each subnet that you want to masquerade. In order to make use of this feature, you must have NAT enabled .
- +Columns are:
- +Example 1: You have eth0 connected to a cable modem and eth1 - connected to your local subnetwork 192.168.9.0/24. Your /etc/shorewall/masq - file would look like:
- - -- -- - -- - -
-- -INTERFACE -SUBNET -ADDRESS -- - - - - - - - - - -eth0 -192.168.9.0/24 --
-
Example 2: You have a number of IPSEC tunnels through ipsec0 - and you want to masquerade traffic from your 192.168.9.0/24 - subnet to the remote subnet 10.1.0.0/16 only.
+ +Example 1: You have eth0 connected to a cable modem and eth1 + connected to your local subnetwork 192.168.9.0/24. Your /etc/shorewall/masq + file would look like:
- + ++ - -- + -
-- -INTERFACE -SUBNET -ADDRESS -- +ipsec0:10.1.0.0/16 -192.168.9.0/24 --
-+ +INTERFACE +SUBNET +ADDRESS ++ - - + + - +eth0 +192.168.9.0/24 ++
+
Example 3: You have a DSL line connected on eth0 and a local - network + +
Example 2: You have a number of IPSEC tunnels through ipsec0 + and you want to masquerade traffic from your 192.168.9.0/24 + subnet to the remote subnet 10.1.0.0/16 only.
+ + ++ + ++ + ++ + +
++ +INTERFACE +SUBNET +ADDRESS ++ + + + + + + + + + +ipsec0:10.1.0.0/16 +192.168.9.0/24 ++
+
Example 3: You have a DSL line connected on eth0 and a local + network (192.168.10.0/24) connected to eth1. You want all local->net @@ -2242,313 +2217,313 @@ an IP address configured on the INTERFACE or you must have ADD_SNAT_ALIASES source address 206.124.146.176.
- -- -- - -- - -
-- -INTERFACE -SUBNET -ADDRESS -- - - - - - - - -eth0 -192.168.10.0/24 -206.124.146.176 -
Example 4: - Same as example 3 - except that you wish - to exclude - 192.168.10.44 and - 192.168.10.45 from - the SNAT rule.
- - - - +- - ++ - Example - 5 (Shorewall version >= 1.3.14): You have a second IP address (206.124.146.177) - assigned to you and wish to use it for SNAT of the subnet 192.168.12.0/24. - You want to give that address the name eth0:0. You must have ADD_SNAT_ALIASES=Yes - in /etc/shorewall/shorewall.conf.- -
-- -INTERFACE -SUBNET -ADDRESS -- + +eth0 -192.168.10.0/24!192.168.10.44,192.168.10.45 -206.124.146.176 -+ +INTERFACE +SUBNET +ADDRESS ++ - - - + + +eth0 +192.168.10.0/24 +206.124.146.176 +
Example 4: + Same as example 3 + except that you wish + to exclude + 192.168.10.44 and + 192.168.10.45 from + the SNAT rule.
+ + + +- + +- -- -
-- -INTERFACE -SUBNET -ADDRESS -- + +eth0:0 -192.168.12.0/24 -206.124.146.177 -+ +INTERFACE +SUBNET +ADDRESS ++ - - - + + +eth0 +192.168.10.0/24!192.168.10.44,192.168.10.45 +206.124.146.176 +
+ ++ ++ + +
++ +INTERFACE +SUBNET +ADDRESS ++ - -eth0:0 +192.168.12.0/24 +206.124.146.177 +If you want to - use proxy ARP on an - entire sub-network, - I suggest that you - look at - - http://www.tldp.org/HOWTO/mini/Proxy-ARP-Subnet/. + +
+ +
If you want to + use proxy ARP on an + entire sub-network, + I suggest that you + look at + + http://www.tldp.org/HOWTO/mini/Proxy-ARP-Subnet/. + If you decide to use the technique described in that HOWTO, you can set the proxy_arp flag for an interface - (/proc/sys/net/ipv4/conf/<interface>/proxy_arp) - by -including the - proxyarp option - in the interface's - record in - - /etc/shorewall/interfaces. - When using Proxy -ARP sub-netting, - you do NOT - include any - entries in - /etc/shorewall/proxyarp.
- - - - -The /etc/shorewall/proxyarp file is used to define Proxy ARP. The file is - typically used for - enabling Proxy ARP - on a small set of - systems since you - need one entry - in - this file for each - system using proxy - ARP. Columns are:
- -Note: After you have made a change to the /etc/shorewall/proxyarp - file, you may need to flush the ARP cache of all routers on -the LAN segment connected to the interface specified in the EXTERNAL - column of the change/added entry(s). If you are having problems communicating - between an individual host (A) on that segment and a system whose - entry has changed, you may need to flush the ARP cache on host -A as well.
- - - -ISPs typically have ARP configured with long -TTL (hours!) so if your ISPs router has a stale cache entry (as seen using -"tcpdump -nei <external interface> host <IP addr>"), it may -take a long while to time out. I personally have had to contact my ISP -and ask them to delete a stale entry in order to restore a system to working -order after changing my proxy ARP settings.
- - - - -Example: - You have public IP addresses 155.182.235.0/28. You configure your - firewall as follows:
- -In your DMZ, you want to install a Web/FTP server with public address - 155.186.235.4. On the Web server, you subnet just like the -firewall's eth0 and you configure 155.186.235.1 as the default -gateway. In your /etc/shorewall/proxyarp file, you will have:
- - -- - -- - -- - -
-- -ADDRESS -INTERFACE -EXTERNAL -HAVEROUTE -- - - - - - - - - - -155.186.235.4 -eth2 -eth0 -No -
Note: You may want to configure the servers in your DMZ with a subnet - that is smaller than the subnet of your internet interface. -See the Proxy ARP Subnet Mini HOWTO (http://www.tldp.org/HOWTO/mini/Proxy-ARP-Subnet/) - for details. In this case you will want to place "Yes" in the - HAVEROUTE column.
- - -To learn how I use Proxy ARP in my DMZ, see my -configuration files.
- - -Warning: Do not use Proxy ARP and -FreeS/Wan on the same system unless you are prepared to suffer the consequences. - If you start or restart Shorewall with an IPSEC tunnel active, - the proxied IP addresses are mistakenly assigned to the IPSEC tunnel - device (ipsecX) rather than to the interface that you specify -in the INTERFACE column of /etc/shorewall/proxyarp. I haven't had -the time to debug this problem so I can't say if it is a bug in the -Kernel or in FreeS/Wan.
- -You might be able to work around this problem using the following - (I haven't tried it):
- -In /etc/shorewall/init, include:
- -qt service ipsec stop
- -In /etc/shorewall/start, include:
- -qt service ipsec start
- - - -The /etc/shorewall/nat file is used to define static NAT. There is one - entry in the file for each static NAT relationship that you - wish to define. In order to make use of this feature, you must - have NAT enabled .
+The /etc/shorewall/proxyarp file is used to define Proxy ARP. The file is + typically used for + enabling Proxy ARP + on a small set of + systems since you + need one entry + in + this file for each + system using proxy + ARP. Columns are:
+ +Note: After you have made a change to the /etc/shorewall/proxyarp + file, you may need to flush the ARP cache of all routers on + the LAN segment connected to the interface specified in the EXTERNAL + column of the change/added entry(s). If you are having problems communicating + between an individual host (A) on that segment and a system +whose entry has changed, you may need to flush the ARP cache +on host A as well.
+ + + +ISPs typically have ARP configured with long TTL + (hours!) so if your ISPs router has a stale cache entry (as seen using "tcpdump + -nei <external interface> host <IP addr>"), it may take a long +while to time out. I personally have had to contact my ISP and ask them +to delete a stale entry in order to restore a system to working order after +changing my proxy ARP settings.
+Example: + You have public IP addresses 155.182.235.0/28. You configure your + firewall as follows:
+ +In your DMZ, you want to install a Web/FTP server with public address + 155.186.235.4. On the Web server, you subnet just like the +firewall's eth0 and you configure 155.186.235.1 as the default +gateway. In your /etc/shorewall/proxyarp file, you will have:
+ + + ++ + ++ + ++ + +
++ +ADDRESS +INTERFACE +EXTERNAL +HAVEROUTE ++ + + + + + + + + + +155.186.235.4 +eth2 +eth0 +No +
Note: You may want to configure the servers in your DMZ with a subnet + that is smaller than the subnet of your internet interface. +See the Proxy ARP Subnet Mini HOWTO (http://www.tldp.org/HOWTO/mini/Proxy-ARP-Subnet/) + for details. In this case you will want to place "Yes" in the + HAVEROUTE column.
+ + + +Warning: Do not use Proxy ARP and + FreeS/Wan on the same system unless you are prepared to suffer the consequences. + If you start or restart Shorewall with an IPSEC tunnel active, + the proxied IP addresses are mistakenly assigned to the IPSEC tunnel + device (ipsecX) rather than to the interface that you specify +in the INTERFACE column of /etc/shorewall/proxyarp. I haven't had +the time to debug this problem so I can't say if it is a bug in the +Kernel or in FreeS/Wan.
+ +You might be able to work around this problem using the following + (I haven't tried it):
+ +In /etc/shorewall/init, include:
+ +qt service ipsec stop
+ +In /etc/shorewall/start, include:
+ +qt service ipsec start
+ + + +The /etc/shorewall/nat file is used to define static NAT. There is one + entry in the file for each static NAT relationship that you + wish to define. In order to make use of this feature, you must + have NAT enabled .
+ + + +- IMPORTANT: If - all you want to do - is forward ports - to servers behind - your firewall, you - do NOT want to use - static NAT. Port - forwarding -can be accomplished - with + color="#ff0000"> + IMPORTANT: If + all you want to do + is forward ports + to servers behind + your firewall, you + do NOT want to use + static NAT. Port + forwarding can +be accomplished + with simple entries in the @@ -2562,39 +2537,39 @@ can be accomplish to static NAT because the internal systems - are accessed -using -the same IP - address internally - and externally.
+ are accessed +using the +same IP + address internally + and externally. - +Columns in an entry are:
- +Look here for additional information and an example. - -
+ +Look here for additional information and an example. + +
- -The /etc/shorewall/tunnels file allows you to define IPSec, GRE, IPIP, -OpenVPN and PPTP tunnels - with end-points on your firewall. To use ipsec, you must install -version 1.9, 1.91 or the current FreeS/WAN development -snapshot.
- -Note: For kernels 2.4.4 and above, you will need to use version 1.91 - or a development snapshot as patching with version 1.9 results - in kernel compilation errors.
+ +The /etc/shorewall/tunnels file allows you to define IPSec, GRE, IPIP, + OpenVPN and PPTP +tunnels with end-points on your firewall. To use ipsec, you must + install version 1.9, 1.91 or the current FreeS/WAN development snapshot. +
- -Instructions for setting up IPSEC tunnels may - be found here, instructions for - IPIP and GRE tunnels are here, instructions for OpenVPN tunnels are here, and -instructions for PPTP tunnels are here.
- + + +Note: For kernels 2.4.4 and above, you will need to use version 1.91 + or a development snapshot as patching with version 1.9 results + in kernel compilation errors.
+ + + +Instructions for setting up IPSEC tunnels may + be found here, instructions for + IPIP and GRE tunnels are here, instructions for OpenVPN tunnels are here, and + instructions for PPTP tunnels are here.
+This file is used to set the following firewall parameters:
- +ZONE | -HOSTS | -BROADCAST | -OPTIONS | -
loc | -eth1 | -- | -dhcp | -
- | -ppp+ | - - |
- - |
-
- Hosts File:
-
ZONE | -HOSTS | -
loc | -ppp+:192.168.12.0/24 | -
- With MERGE_HOSTS=No, the loc zone
- consists of only ppp+:192.168.12.0/24; with MERGE_HOSTS=Yes,
- it includes eth1:0.0.0.0/0 and ppp+:192.168.12.0/24.
-
Rules not meeting those criteria will continue to generate an individual - rule for each listed port or port range.
-Rules not meeting those criteria will continue to generate an individual + rule for each listed port or port range.
+The file /etc/shorewall/modules contains commands for loading the kernel - modules required by Shorewall-defined firewall rules. Shorewall - will source this file during start/restart provided that it -exists and that the directory specified by the MODULESDIR parameter -exists (see /etc/shorewall/shorewall.conf -above).
+ +The file /etc/shorewall/modules contains commands for loading the kernel + modules required by Shorewall-defined firewall rules. Shorewall + will source this file during start/restart provided that it +exists and that the directory specified by the MODULESDIR parameter +exists (see /etc/shorewall/shorewall.conf above).
- -The file that is released with Shorewall calls the Shorewall function - "loadmodule" for the set of modules that I load.
+ +The file that is released with Shorewall calls the Shorewall function + "loadmodule" for the set of modules that I load.
- +The loadmodule function is called as follows:
- -- - - -- - - +loadmodule - <modulename> - [ <module parameters> ]
-
+ + + + ++ + + +loadmodule + <modulename> + [ <module parameters> ]
+
where
- -+ +- -++<modulename>
- -- - - - -+ +is the name of the modules without the trailing ".o" (example - ip_conntrack).
-- ++ + + + +is the name of the modules without the trailing ".o" (example + ip_conntrack).
+<module parameters>
- -+ ++- + +-Optional parameters to the insmod utility.
-
The function determines if the module named by <modulename> - is already loaded and if not then the function determines - if the ".o" file corresponding to the module exists in the moduledirectory; - if so, then the following command is executed:
+ +The function determines if the module named by <modulename> + is already loaded and if not then the function determines + if the ".o" file corresponding to the module exists in the moduledirectory; + if so, then the following command is executed:
- -+ +-- -- - - - -insmod moduledirectory/<modulename>.o <module - parameters>
-If the file doesn't exist, the function determines of the ".o.gz" - file corresponding to the module exists in the moduledirectory. -If it does, the function assumes that the running configuration supports -compressed modules and execute the following command:
- - - - -- - - - -- - - - -insmod moduledirectory/<modulename>.o.gz <module - parameters>
-- /etc/shorewall/tos Configuration
+ +insmod moduledirectory/<modulename>.o <module + parameters>
+
The /etc/shorewall/tos file allows you to set the Type of Service field - in packet headers based on packet source, packet destination, - protocol, source port and destination port. In order for this - file to be processed by Shorewall, you must have If the file doesn't exist, the function determines of the ".o.gz" +file corresponding to the module exists in the moduledirectory. If +it does, the function assumes that the running configuration supports compressed + modules and execute the following command:
+ + + + ++ + + + ++ + + + +insmod moduledirectory/<modulename>.o.gz <module + parameters>
+
The /etc/shorewall/tos file allows you to set the Type of Service field + in packet headers based on packet source, packet destination, + protocol, source port and destination port. In order for this + file to be processed by Shorewall, you must have mangle support enabled .
- +Entries in the file have the following columns:
- +- - - -- - - -- - - --Minimize-Delay (16)
-
- Maximize-Throughput (8)
- Maximize-Reliability (4)
- Minimize-Cost (2)
- Normal-Service (0)
The /etc/shorewall/tos file that is included with Shorewall contains - the following entries.
- - - ++ + ++ + + ++ + + + ++Minimize-Delay (16)
+
+ Maximize-Throughput (8)
+ Maximize-Reliability (4)
+ Minimize-Cost (2)
+ Normal-Service (0)
The /etc/shorewall/tos file that is included with Shorewall contains + the following entries.
+ + + +++ - -- + -
-- -SOURCE -DEST -PROTOCOL -SOURCE -
- PORT(S)DEST PORT(S) -TOS -- -all -all -tcp -- -ssh -16 -- -all -all -tcp -ssh -- -16 -- -all -all -tcp -- -ftp -16 -- -all -all -tcp -ftp -- -16 -- -all -all -tcp -- -ftp-data -8 -- +all -all -tcp -ftp-data -- -8 -+ +SOURCE +DEST +PROTOCOL +SOURCE +
+ PORT(S)DEST PORT(S) +TOS ++ +all +all +tcp +- +ssh +16 ++ +all +all +tcp +ssh +- +16 ++ +all +all +tcp +- +ftp +16 ++ +all +all +tcp +ftp +- +16 ++ +all +all +tcp +- +ftp-data +8 ++ - - + + - +all +all +tcp +ftp-data +- +8 +
WARNING: Users have reported that odd routing problems result from - adding the ESP and AH protocols to the /etc/shorewall/tos file. -
+ +WARNING: Users have reported that odd routing problems result from + adding the ESP and AH protocols to the /etc/shorewall/tos file. +
- +Each - line - in - /etc/shorewall/blacklist - contains - - an - IP - address, a MAC address in Shorewall Format - or - subnet - address. - - Example:
+ +Each + line + in + /etc/shorewall/blacklist + contains - + an + IP + address, a MAC address in Shorewall Format + or + subnet + address. + + Example:
+ +130.252.100.69- -
206.124.146.0/24
Packets - from - hosts - listed - in - - the - blacklist - file - will - be + +
Packets
+ from
+ hosts
+ listed
+ in
- disposed
- of
- according
- to
- the
+ the
+ blacklist
+ file
+ will
- value
- assigned
- to
- the BLACKLIST_DISPOSITION
-
- and BLACKLIST_LOGLEVEL variables
+be
+ disposed
+ of
+ according
+ to
+ the
- in
- /etc/shorewall/shorewall.conf.
- Only
- packets
-
- arriving
- on
- interfaces
- that
- have
+ value
+ assigned
+ to
+ the BLACKLIST_DISPOSITION
- the
- 'blacklist'
- option
+ and BLACKLIST_LOGLEVEL variables
- in
- /etc/shorewall/interfaces
- are
- checked
+ in
+ /etc/shorewall/shorewall.conf.
+ Only
+ packets
- against
- the
- blacklist. The black list is designed to prevent
- listed hosts/subnets from accessing services on your
- network.
-
Beginning with Shorewall 1.3.8, the blacklist file has three columns:
-
Shorewall also has a dynamic blacklist - capability.
+ +Shorewall also has a dynamic blacklist + capability.
- -IMPORTANT: The Shorewall blacklist file is NOT
- designed to police your users' web browsing -- to do that, I
+
+ IMPORTANT: The Shorewall blacklist file is NOT
+ designed to police your users' web browsing -- to do that, I
suggest that you install and configure Squid (http://www.squid-cache.org). This file lists the subnets affected by the norfc1918
- interface option. Columns in the file are: This file lists the subnets affected by the norfc1918
+ interface option. Columns in the file are: This file defines the hosts that are accessible from the firewall when
- the firewall is stopped. Columns in the file are: This file defines the hosts that are accessible from the firewall when
+ the firewall is stopped. Columns in the file are: Example: When your firewall is stopped, you want firewall accessibility
- from local hosts 192.168.1.0/24 and from your DMZ. Your DMZ interfaces
- through eth1 and your local hosts through eth2. Example: When your firewall is stopped, you want firewall accessibility
+ from local hosts 192.168.1.0/24 and from your DMZ. Your DMZ interfaces
+ through eth1 and your local hosts through eth2. Updated 2/18/2003 - Tom Eastep
+ Updated 3/4/2003 - Tom Eastep
- Copyright © 2001, 2002, 2003 Thomas M. Eastep./etc/shorewall/rfc1918 (Added in Version 1.3.1)
-
-
-
-
-
-
- /etc/shorewall/routestopped (Added in Version
- 1.3.4)
+
+/etc/shorewall/routestopped (Added in Version
+ 1.3.4)
-
-
-
-
-
+
+
-
-
-
-
-
-
-
+
+
+
+
+
+
+
-
-
+
+
+
-
+
- INTERFACE
+ INTERFACE
- HOST(S)
+ HOST(S)
-
+
-
+
- eth2
+ eth2
- 192.168.1.0/24
+ 192.168.1.0/24
-
+
-
+
+
+
+
+
+
+
+ eth1
+ eth1
- -
+ -
- /etc/shorewall/maclist (Added in Version 1.3.10)
+ This file is described in the MAC Validation Documentation.
+
+
+/etc/shorewall/maclist (Added in Version 1.3.10)
- This file is described in the MAC Validation Documentation.
-
-
-
-
-
-
-
-
-
-
-
-
-
+
+ |
-
+
Shorewall FAQs- |
-
1a. Ok -- I followed those instructions
- but it doesn't work.
-
1a. Ok -- I followed those instructions
+ but it doesn't work.
+
1b. I'm still having problems with - port forwarding
- - + +1b. I'm still having problems with + port forwarding
+ + - - + + - -3. I want to use Netmeeting - or MSN Instant Messenger with Shorewall. What do - I do?
+ +3. I want to use Netmeeting + or MSN Instant Messenger with Shorewall. What +do I do?
- - + + - -4a. I just ran an nmap UDP scan - of my firewall and it showed 100s of ports as open!!!!
+ +4a. I just ran an nmap UDP scan + of my firewall and it showed 100s of ports as open!!!!
- -5. I've installed Shorewall and now - I can't ping through the firewall
+ +5. I've installed Shorewall and now + I can't ping through the firewall
- -6. Where are the log messages - written and how do I change the destination?
+ +6. Where are the log messages + written and how do I change the destination?
- -6a. Are there any log parsers - that work with Shorewall?
- + +6a. Are there any log parsers + that work with Shorewall?
+6b. DROP messages on port 10619 are flooding the logs with their connect
- requests. Can i exclude these error messages for this port temporarily
-from logging in Shorewall?
-
8. When I try to start Shorewall - on RedHat I get messages about insmod failing -- what's - wrong?
+ +8. When I try to start Shorewall + on RedHat I get messages about insmod failing -- +what's wrong?
- -9. Why can't Shorewall detect - my interfaces properly?
+ +9. Why can't Shorewall detect + my interfaces properly?
- -10. What distributions does - it work with?
+ +10. What distributions does + it work with?
- -11. What features does it -support?
+ +11. What features does it + support?
- +12. Is there a GUI?
- +13. Why do you call it "Shorewall"?
- - + + - - + + - -15. My local systems can't see - out to the net
+ +15. My local systems can't see + out to the net
- -16. Shorewall is writing log messages
- all over my console making it unusable!
-
16. Shorewall is writing log messages
+ all over my console making it unusable!
+
Answer: The first example in the rules file documentation shows how to - do port forwarding under Shorewall. The format of a port-forwarding - rule to a local system is as follows:
+ href="Documentation.htm#Rules">rules file documentation shows how to + do port forwarding under Shorewall. The format of a port-forwarding + rule to a local system is as follows: - -- + +- -++- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -SOURCE PORT -ORIG. DEST. -- + +DNAT -net -loc:<local IP address>[:<local - port>] -<protocol> -<port #> --
--
-+ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +SOURCE PORT +ORIG. DEST. ++ - - - + + +DNAT +net +loc:<local IP address>[:<local + port>] +<protocol> +<port #> ++
++
+
So to forward UDP port 7777 to internal system 192.168.1.5, - the rule is:
+ +So to forward UDP port 7777 to internal system 192.168.1.5, + the rule is:
- -- + +- -++- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -SOURCE PORT -ORIG. DEST. -- + +DNAT -net -loc:192.168.1.5 -udp -7777 --
--
-+ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +SOURCE PORT +ORIG. DEST. ++ - - - + + +DNAT +net +loc:192.168.1.5 +udp +7777 ++
++
+
- + +-Finally, if you need to forward a range of ports, in the PORT column specify -the range as low-port:high-port.++- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -SOURCE PORT -ORIG. DEST. -- + +DNAT -net -loc:<local IP address>[:<local - port>] -<protocol> -<port #> -- -<external IP> -+ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +SOURCE PORT +ORIG. DEST. ++ - - - + + +DNAT +net +loc:<local IP address>[:<local + port>] +<protocol> +<port #> +- +<external IP> +
Answer: That is usually the result of one of two things:
- +Answer: I have two objections to this setup.
- +If you insist on an IP solution to the accessibility problem - rather than a DNS solution, then assuming that your external - interface is eth0 and your internal interface is eth1 and - that eth1 has IP address 192.168.1.254 with subnet 192.168.1.0/24, - do the following:
- -a) In /etc/shorewall/interfaces, specify "multi" as an option - for eth1 (No longer required as of Shorewall version 1.3.9).
+ +If you insist on an IP solution to the accessibility problem + rather than a DNS solution, then assuming that your +external interface is eth0 and your internal interface +is eth1 and that eth1 has IP address 192.168.1.254 with subnet +192.168.1.0/24, in /etc/shorewall/rules, add:
- -b) In /etc/shorewall/rules, add:
-- + +++++-- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -SOURCE PORT -ORIG. DEST. -- + +DNAT -loc:192.168.1.0/24 -loc:192.168.1.5 -tcp -www -- -130.151.100.69:192.168.1.254 -+ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +SOURCE PORT +ORIG. DEST. ++ - - - + + +DNAT +loc:192.168.1.0/24 +loc:192.168.1.5 +tcp +www +- +130.151.100.69:192.168.1.254 +
That rule only works of course if you have a static external - IP address. If you have a dynamic IP address and are running - Shorewall 1.3.4 or later then include this in /etc/shorewall/params:
-That rule only works of course if you have a static external + IP address. If you have a dynamic IP address and are + running Shorewall 1.3.4 or later then include this in /etc/shorewall/params:
+ETH0_IP=`find_interface_address eth0`-
and make your DNAT rule:
-- + +++++-- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -SOURCE PORT -ORIG. DEST. -- + +DNAT -loc:192.168.1.0/24 -loc:192.168.1.5 -tcp -www -- -$ETH0_IP:192.168.1.254 -+ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +SOURCE PORT +ORIG. DEST. ++ - - - + + +DNAT +loc:192.168.1.0/24 +loc:192.168.1.5 +tcp +www +- +$ETH0_IP:192.168.1.254 +
Using this technique, you will want to configure your DHCP/PPPoE - client to automatically restart Shorewall each time that - you get a new IP address.
-Using this technique, you will want to configure your DHCP/PPPoE + client to automatically restart Shorewall each time +that you get a new IP address.
+Answer: This is another problem that is best solved - using Bind Version 9 "views". It allows both external and - internal clients to access a NATed host using the host's DNS - name.
+ +Answer: This is another problem that is best solved + using Bind Version 9 "views". It allows both external +and internal clients to access a NATed host using the host's + DNS name.
- -Another good way to approach this problem is to switch from - static NAT to Proxy ARP. That way, the hosts in Z have -non-RFC1918 addresses and can be accessed externally and + +
Another good way to approach this problem is to switch from + static NAT to Proxy ARP. That way, the hosts in Z have + non-RFC1918 addresses and can be accessed externally and internally using the same address.
- -If you don't like those solutions and prefer routing all Z->Z -traffic through your firewall then:
+ +If you don't like those solutions and prefer routing all +Z->Z traffic through your firewall then:
- -a) Specify "multi" on the entry for Z's interface in /etc/shorewall/interfaces
- (If you are running a Shorewall version earlier than 1.3.9).
- b) Set the Z->Z policy to ACCEPT.
- c) Masquerade Z to itself.
-
- Example:
a) Set the Z->Z policy to ACCEPT.
+ b) Masquerade Z to itself.
+
+ Example:
Zone: dmz
- Interface: eth2
- Subnet: 192.168.2.0/24
In /etc/shorewall/interfaces:
- -- + +- +++- -
-- -ZONE -INTERFACE -BROADCAST -OPTIONS -- + +dmz -eth2 -192.168.2.255 -multi -+ +ZONE +INTERFACE +BROADCAST +OPTIONS ++ - - - + + +dmz +eth2 +192.168.2.255 ++
+
In /etc/shorewall/policy:
- -- + +- +++- -
-- -SOURCE -DESTINATION -POLICY -LIMIT:BURST -- + +dmz -dmz -ACCEPT --
-+ +SOURCE +DESTINATION +POLICY +LIMIT:BURST ++ - - - + + +dmz +dmz +ACCEPT ++
+
In /etc/shorewall/masq:
+ ++ ++ + ++ +
++ +INTERFACE + +SUBNET +ADDRESS ++ + + + + + + +eth2 +192.168.2.0/24 ++
+
Answer: There is an H.323 connection + tracking/NAT module that may help with Netmeeting. + Look here for a solution + for MSN IM but be aware that there are significant security risks involved + with this solution. Also check the Netfilter mailing list +archives at http://www.netfilter.org. +
+ + +Answer: The common.def included with version 1.3.x + always rejects connection requests on TCP port 113 +rather than dropping them. This is necessary to prevent +outgoing connection problems to services that use the 'Auth' +mechanism for identifying requesting users. Shorewall also +rejects TCP ports 135, 137 and 139 as well as UDP ports 137-139. + These are ports that are used by Windows (Windows can +be configured to use the DCE cell locator on port 135). Rejecting +these connection requests rather than dropping them cuts down +slightly on the amount of Windows chatter on LAN segments connected + to the Firewall.
+ + +If you are seeing port 80 being 'closed', that's probably + your ISP preventing you from running a web server +in violation of your Service Agreement.
+ + +Answer: Take a deep breath and read the nmap man page + section about UDP scans. If nmap gets nothing + back from your firewall then it reports the port as open. + If you want to see which UDP ports are really open, temporarily + change your net->all policy to REJECT, restart Shorewall +and do the nmap UDP scan again.
+ + +Answer: If you want your firewall to be totally open + for "ping",
+ + +a) Create /etc/shorewall/common if it doesn't already exist.
+
+ b) Be sure that the first command
+in the file is ". /etc/shorewall/common.def"
+ c) Add the following to /etc/shorewall/common
+
+ ++ For a complete description of Shorewall 'ping' management, + see this page. + +run_iptables -A icmpdef -p ICMP --icmp-type echo-request + -j ACCEPT
+
+
Answer: NetFilter uses the kernel's equivalent of +syslog (see "man syslog") to log messages. It always uses the LOG_KERN (kern) +facility (see "man openlog") and you get to choose the log level (again, +see "man syslog") in your policies + and rules. The destination for messaged + logged by syslog is controlled by /etc/syslog.conf (see "man syslog.conf"). + When you have changed /etc/syslog.conf, be sure to restart + syslogd (on a RedHat system, "service syslog restart").
+ + +By default, older versions of Shorewall ratelimited log messages + through settings +in /etc/shorewall/shorewall.conf -- If you want to log +all messages, set:
+ + +LOGLIMIT=""+
LOGBURST=""
Beginning with Shorewall version 1.3.12, you can set up Shorewall to log all of its messages to a separate file.
Answer: Here are several links that may be helpful: +
+ + ++ ++ I personnaly use Logwatch. It emails me a report each + day from my various systems with each report summarizing the logged + activity on the corresponding system. + +http://www.shorewall.net/pub/shorewall/parsefw/
+
+ http://www.fireparse.com
+ http://cert.uni-stuttgart.de/projects/fwlogwatch
+ http://www.logwatch.org
+ http://gege.org/iptables
+
DROP net fw udp 10619+ +
Jan 8 15:50:48 norcomix kernel: Shorewall:net2all:DROP:IN=eth0 OUT= MAC=00:40:c7:2e:09:c0:00:01:64:4a:70:00:08:00+ Answer: There are two possibilities:
SRC=208.138.130.16 DST=24.237.22.45 LEN=53 TOS=0x00 PREC=0x00
TTL=251 ID=8288 DF PROTO=UDP SPT=53 DPT=40275 LEN=33
++ The above file is also include in all of my sample configurations + available in the Quick Start +Guides and in the common.def file in Shorewall 1.4.0 and later.#+
# Include the standard common.def file
#
. /etc/shorewall/common.def
#
# The following rule is non-standard and compensates for tardy
# DNS replies
#
run_iptables -A common -p udp --sport 53 -mstate --state NEW -j DROP
The 'stop' command is intended to place your firewall into + a safe state whereby only those hosts listed in /etc/shorewall/routestopped' + are activated. If you want to totally open up your firewall, + you must use the 'shorewall clear' command.
+ + +Answer: The output you will see looks something like + this:
+ + +/lib/modules/2.4.17/kernel/net/ipv4/netfilter/ip_tables.o: init_module: Device or resource busy+ + +
Hint: insmod errors can be caused by incorrect module parameters, including invalid IO or IRQ parameters
/lib/modules/2.4.17/kernel/net/ipv4/netfilter/ip_tables.o: insmod
/lib/modules/2.4.17/kernel/net/ipv4/netfilter/ip_tables.o failed
/lib/modules/2.4.17/kernel/net/ipv4/netfilter/ip_tables.o: insmod ip_tables failed
iptables v1.2.3: can't initialize iptables table `nat': iptables who? (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.
This is usually cured by the following sequence of commands: +
+ + +service ipchains stop+
chkconfig --delete ipchains
rmmod ipchains
Also, be sure to check the errata + for problems concerning the version of iptables (v1.2.3) + shipped with RH7.2.
+I just installed Shorewall and when I issue the start command, + I see the following:
+ + +Processing /etc/shorewall/shorewall.conf ...+
Processing /etc/shorewall/params ...
Starting Shorewall...
Loading Modules...
Initializing...
Determining Zones...
Zones: net loc
Validating interfaces file...
Validating hosts file...
Determining Hosts in Zones...
Net Zone: eth0:0.0.0.0/0
Local Zone: eth1:0.0.0.0/0
Deleting user chains...
Creating input Chains...
...
Why can't Shorewall detect my interfaces properly?
+Answer: The above output is perfectly normal. The +Net zone is defined as all hosts that are connected through eth0 and the +local zone is defined as all hosts connected through eth1
+Shorewall works with any GNU/Linux distribution that includes + the proper +prerequisites.
+ + +Answer: See the Shorewall + Feature List.
+ + +Answer: Yes. Shorewall support is included in Webmin + 1.060 and later versions. See http://www.webmin.com +
+ + +Answer: Shorewall is a concatenation of "Shoreline" + (the city + where I live) and "Firewall". The full name of + the product is actually "Shoreline Firewall" but "Shorewall" is must + more commonly used.
+ + +Is there any way it can add a rule before the rfc1918 blocking + that will let all traffic to and from the 192.168.100.1 + address of the modem in/out but still block all other rfc1918 + addresses?
+ + +Answer: If you are running a version of Shorewall +earlier than 1.3.1, create /etc/shorewall/start and in it, place the +following:
+ + +run_iptables -I rfc1918 -s 192.168.100.1 -j ACCEPT+
If you are running version 1.3.1 or later, simply add the + following to /etc/shorewall/rfc1918:
++ +++ +
++ +SUBNET +TARGET ++ + + + + + + +192.168.100.1 +RETURN +
Be sure that you add the entry ABOVE the entry for 192.168.0.0/16.
+
Note: If you add a second IP address to your external firewall
+ interface to correspond to the modem address, you must
+also make an entry in /etc/shorewall/rfc1918 for that address.
+For example, if you configure the address 192.168.100.2 on your
+firewall, then you would add two entries to /etc/shorewall/rfc1918:
+
+
-+ Example:+
- --
- - - -- -INTERFACE - -SUBNET -ADDRESS -- - - - - - - -eth2 -192.168.2.0/24 --
-3. I want to use Netmeeting or MSN Instant - Messenger with Shorewall. What do I do?
- - -Answer: There is an H.323 connection - tracking/NAT module that may help with Netmeeting. Look - here for a solution for -MSN IM but be aware that there are significant security risks involved with -this solution. Also check the Netfilter mailing list archives - at http://www.netfilter.org. -
- - -4. I just used an online port scanner - to check my firewall and it shows some ports as 'closed' - rather than 'blocked'. Why?
- - -Answer: The common.def included with version 1.3.x - always rejects connection requests on TCP port 113 rather - than dropping them. This is necessary to prevent outgoing - connection problems to services that use the 'Auth' mechanism - for identifying requesting users. Shorewall also rejects TCP - ports 135, 137 and 139 as well as UDP ports 137-139. These are - ports that are used by Windows (Windows can be configured - to use the DCE cell locator on port 135). Rejecting these connection - requests rather than dropping them cuts down slightly on the amount - of Windows chatter on LAN segments connected to the Firewall.
- - -If you are seeing port 80 being 'closed', that's probably - your ISP preventing you from running a web server in -violation of your Service Agreement.
- - -4a. I just ran an nmap UDP scan of my - firewall and it showed 100s of ports as open!!!!
- - -Answer: Take a deep breath and read the nmap man page - section about UDP scans. If nmap gets nothing -back from your firewall then it reports the port as open. -If you want to see which UDP ports are really open, temporarily - change your net->all policy to REJECT, restart Shorewall and - do the nmap UDP scan again.
- - -5. I've installed Shorewall and now I - can't ping through the firewall
- - -Answer: If you want your firewall to be totally open - for "ping":
- - -a) Do NOT specify 'noping' on any interface in /etc/shorewall/interfaces.
- - -
- b) Copy /etc/shorewall/icmp.def to -/etc/shorewall/icmpdef
- c) Add the following to /etc/shorewall/icmpdef: -- -- For a complete description of Shorewall 'ping' management, -see this page. - -run_iptables -A icmpdef -p ICMP --icmp-type echo-request - -j ACCEPT
-
-6. Where are the log messages written - and how do I change the destination?
- - -Answer: NetFilter uses the kernel's equivalent of syslog -(see "man syslog") to log messages. It always uses the LOG_KERN (kern) facility -(see "man openlog") and you get to choose the log level (again, see "man -syslog") in your policies and rules. The destination for messaged -logged by syslog is controlled by /etc/syslog.conf (see "man syslog.conf"). - When you have changed /etc/syslog.conf, be sure to restart - syslogd (on a RedHat system, "service syslog restart").
- - -By default, older versions of Shorewall ratelimited log messages - through settings in - /etc/shorewall/shorewall.conf -- If you want to log all messages, - set:
- - --- - -LOGLIMIT=""-
LOGBURST=""
Beginning with Shorewall version 1.3.12, you can set up Shorewall to log all of its messages to a separate file.6a. Are there any log parsers that work - with Shorewall?
- - -Answer: Here are several links that may be helpful: -
- - -- -- I personnaly use Logwatch. It emails me a report each -day from my various systems with each report summarizing the logged -activity on the corresponding system. - -http://www.shorewall.net/pub/shorewall/parsefw/
-
- http://www.fireparse.com
- http://cert.uni-stuttgart.de/projects/fwlogwatch
- http://www.logwatch.org
- http://gege.org/iptables
-6b. DROP messages on port 10619 - are flooding the logs with their connect requests. Can i exclude - these error messages for this port temporarily from logging in Shorewall?
- Temporarily add the following rule:
- -DROP net fw udp 10619- -6c. All day long I get a steady flow - of these DROP messages from port 53 to some high numbered port. They -get dropped, but what the heck are they?
- -Jan 8 15:50:48 norcomix kernel: Shorewall:net2all:DROP:IN=eth0 OUT= MAC=00:40:c7:2e:09:c0:00:01:64:4a:70:00:08:00- Answer: There are two possibilities:
SRC=208.138.130.16 DST=24.237.22.45 LEN=53 TOS=0x00 PREC=0x00
TTL=251 ID=8288 DF PROTO=UDP SPT=53 DPT=40275 LEN=33
- --
- You can distinguish the difference by setting the logunclean -option (/etc/shorewall/interfaces) - on your external interface (eth0 in the above example). If they get logged - twice, they are corrupted. I solve this problem by using an /etc/shorewall/common - file like this:- They are late-arriving replies to DNS queries.
-- They are corrupted reply packets.
- -
- --- The above file is also include in all of my sample configurations available - in the Quick Start Guides.#-
# Include the standard common.def file
#
. /etc/shorewall/common.def
#
# The following rule is non-standard and compensates for tardy
# DNS replies
#
run_iptables -A common -p udp --sport 53 -mstate --state NEW -j DROP
- -6d. Why is the MAC address in -Shorewall log messages so long? I thought MAC addresses were only 6 bytes -in length. What is labeled as the MAC address in a Shorewall log message -is actually the Ethernet frame header. In contains:
-
--
- Example:- the destination MAC address (6 bytes)
-- the source MAC address (6 bytes)
-- the ethernet frame type (2 bytes)
-
-
- MAC=00:04:4c:dc:e2:28:00:b0:8e:cf:3c:4c:08:00
- --
-- Destination MAC address = 00:04:4c:dc:e2:28
-- Source MAC address = 00:b0:8e:cf:3c:4c
-- Ethernet Frame Type = 08:00 (IP Version 4)
-7. When I stop Shorewall using 'shorewall - stop', I can't connect to anything. Why doesn't that command - work?
- - -The 'stop' command is intended to place your firewall into - a safe state whereby only those hosts listed in /etc/shorewall/routestopped' - are activated. If you want to totally open up your firewall, - you must use the 'shorewall clear' command.
- - -8. When I try to start Shorewall on RedHat, - I get messages about insmod failing -- what's wrong?
- - -Answer: The output you will see looks something like - this:
- - -/lib/modules/2.4.17/kernel/net/ipv4/netfilter/ip_tables.o: init_module: Device or resource busy- - -
Hint: insmod errors can be caused by incorrect module parameters, including invalid IO or IRQ parameters
/lib/modules/2.4.17/kernel/net/ipv4/netfilter/ip_tables.o: insmod
/lib/modules/2.4.17/kernel/net/ipv4/netfilter/ip_tables.o failed
/lib/modules/2.4.17/kernel/net/ipv4/netfilter/ip_tables.o: insmod ip_tables failed
iptables v1.2.3: can't initialize iptables table `nat': iptables who? (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.This is usually cured by the following sequence of commands: -
- - --- - -service ipchains stop-
chkconfig --delete ipchains
rmmod ipchains-- - -Also, be sure to check the errata - for problems concerning the version of iptables (v1.2.3) - shipped with RH7.2.
-- -
9. Why can't Shorewall detect my interfaces - properly?
- - -I just installed Shorewall and when I issue the start command, - I see the following:
- - --- - -Processing /etc/shorewall/shorewall.conf ...-
Processing /etc/shorewall/params ...
Starting Shorewall...
Loading Modules...
Initializing...
Determining Zones...
Zones: net loc
Validating interfaces file...
Validating hosts file...
Determining Hosts in Zones...
Net Zone: eth0:0.0.0.0/0
Local Zone: eth1:0.0.0.0/0
Deleting user chains...
Creating input Chains...
...-- - -Why can't Shorewall detect my interfaces properly?
--- - -Answer: The above output is perfectly normal. The Net - zone is defined as all hosts that are connected through eth0 and the local - zone is defined as all hosts connected through eth1
-10. What Distributions does it work - with?
- - -Shorewall works with any GNU/Linux distribution that includes - the proper prerequisites.
- -11. What Features does it have?
- - -Answer: See the Shorewall - Feature List.
- -12. Is there a GUI?
- - -Answer: Yes. Shorewall support is included in Webmin -1.060 and later versions. See http://www.webmin.com -
- -13. Why do you call it "Shorewall"?
- - -Answer: Shorewall is a concatenation of "Shoreline" - (the city -where I live) and "Firewall". The full name of the -product is actually "Shoreline Firewall" but "Shorewall" is must more -commonly used.
- -14. I'm connected via a cable modem - and it has an internal web server that allows me to configure/monitor - it but as expected if I enable rfc1918 blocking for my eth0 - interface (the internet one), it also blocks the cable modems - web server.
- - -Is there any way it can add a rule before the rfc1918 blocking - that will let all traffic to and from the 192.168.100.1 -address of the modem in/out but still block all other rfc1918 -addresses?
- - -Answer: If you are running a version of Shorewall earlier -than 1.3.1, create /etc/shorewall/start and in it, place the following:
- --- - -run_iptables -I rfc1918 -s 192.168.100.1 -j ACCEPT--- - -If you are running version 1.3.1 or later, simply add the - following to /etc/shorewall/rfc1918:
--+ + - -- --- -
-- SUBNET -TARGET ++ SUBNET +
+TARGET
+- +192.168.100.1 -RETURN +192.168.100.1 +
+RETURN +
++ - - + +192.168.100.2 +
+RETURN
+-+ +Be sure that you add the entry ABOVE the entry for 192.168.0.0/16.
- -
-Note: If you add a second IP address to your external firewall - interface to correspond to the modem address, you must also - make an entry in /etc/shorewall/rfc1918 for that address. For - example, if you configure the address 192.168.100.2 on your firewall, - then you would add two entries to /etc/shorewall/rfc1918:
- -
-- --15. My local systems can't see out to + the net
- --+ +14a. Even though it assigns public IP - addresses, my ISP's DHCP server has an RFC 1918 address. If I enable RFC -1918 filtering on my external interface, my DHCP client cannot renew its -lease.
-Answer: Every time I read "systems can't see out to + the net", I wonder where the poster bought computers +with eyes and what those computers will "see" when things +are working properly. That aside, the most common causes of +this problem are:
- --- - -The solution is the same as FAQ 14 above. Simply substitute - the IP address of your ISPs DHCP server.
-15. My local systems can't see out to - the net
- - -Answer: Every time I read "systems can't see out to - the net", I wonder where the poster bought computers with - eyes and what those computers will "see" when things are working - properly. That aside, the most common causes of this problem - are:
- - +-
- -- +
- - -
-The default gateway on each local system isn't set to - the IP address of the local firewall interface.
-- + +
+The default gateway on each local system isn't set to + the IP address of the local firewall interface.
+- - -
-The entry for the local network in the /etc/shorewall/masq - file is wrong or missing.
-- + +
+The entry for the local network in the /etc/shorewall/masq + file is wrong or missing.
+- - -
+ +The DNS settings on the local systems are wrong or the - user is running a DNS server on the firewall and hasn't - enabled UDP and TCP port 53 from the firewall to the internet.
-The DNS settings on the local systems are wrong or the + user is running a DNS server on the firewall and hasn't + enabled UDP and TCP port 53 from the firewall to the +internet.
+ - +16. Shorewall is writing log messages - all over my console making it unusable!
+ +16. Shorewall is writing log messages + all over my console making it unusable!
- -Answer: "man dmesg" -- add a suitable 'dmesg' command - to your startup scripts or place it in /etc/shorewall/start. - Under RedHat, the max log level that is sent to the console - is specified in /etc/sysconfig/init in the LOGLEVEL variable.
- -
-17. How do I find out why this traffic is getting - logged?
- Answer: Logging occurs out of a number - of chains (as indicated in the log message) in Shorewall:
- + +Answer: "man dmesg" -- add a suitable 'dmesg' command + to your startup scripts or place it in /etc/shorewall/start. + Under RedHat, the max log level that is sent to the +console is specified in /etc/sysconfig/init in the LOGLEVEL +variable.
+ +
+17. How do I find out why this traffic is getting + logged?
+ Answer: Logging occurs out of +a number of chains (as indicated in the log message) in Shorewall:
+-
- -- man1918 - The destination address - is listed in /etc/shorewall/rfc1918 with a logdrop target - -- see /etc/shorewall/rfc1918.
-- rfc1918 - The source address - is listed in /etc/shorewall/rfc1918 with a logdrop target - -- see /etc/shorewall/rfc1918.
-- all2<zone>, <zone>2all - or all2all - You have a policy that specifies a log level - and this packet is being logged under that policy. If you intend - to ACCEPT this traffic then you need a man1918 - The destination + address is listed in /etc/shorewall/rfc1918 with a logdrop + target -- see /etc/shorewall/rfc1918.
+- rfc1918 - The source address + is listed in /etc/shorewall/rfc1918 with a logdrop target + -- see /etc/shorewall/rfc1918.
+- all2<zone>, <zone>2all + or all2all - You have a policy that specifies a log level + and this packet is being logged under that policy. If you intend + to ACCEPT this traffic then you need a rule to that effect.
-
-- <zone1>2<zone2> - - Either you have a policy for - <zone1> to <zone2> that specifies - a log level and this packet is being logged under that policy - or this packet matches a rule - that includes a log level.
-- <interface>_mac - The packet -is being logged under the maclist +
- <zone1>2<zone2> + - Either you have a +policy for <zone1> to <zone2> +that specifies a log level and this packet is being logged +under that policy or this packet matches a rule that includes a log level.
+- <interface>_mac - The packet + is being logged under the maclist interface option.
-
-- logpkt - The packet is being - logged under the logunclean +
+- logpkt - The packet is being + logged under the logunclean interface option.
-- badpkt - The packet is being - logged under the dropunclean interface option as specified - in the LOGUNCLEAN setting in /etc/shorewall/shorewall.conf.
-- blacklst - The packet is being - logged because the source IP is blacklisted in thebadpkt - The packet is being + logged under the dropunclean interface option as specified + in the LOGUNCLEAN setting in /etc/shorewall/shorewall.conf.
+- blacklst - The packet is +being logged because the source IP is blacklisted in the /etc/shorewall/blacklist file.
-- newnotsyn - The packet is being - logged because it is a TCP packet that is not part of any current - connection yet it is not a syn packet. Options affecting the logging - of such packets include NEWNOTSYN and LOGNEWNOTSYN - in /etc/shorewall/shorewall.conf.
-- INPUT or FORWARD - The - packet has a source IP address that isn't in any of your defined - zones ("shorewall check" and look at the printed zone definitions) - or the chain is FORWARD and the destination IP isn't in any of your - defined zones.
-- logflags - The packet is being logged -because it failed the checks implemented by the tcpflags newnotsyn - The packet is + being logged because it is a TCP packet that is not part +of any current connection yet it is not a syn packet. Options +affecting the logging of such packets include NEWNOTSYN + and LOGNEWNOTSYN in /etc/shorewall/shorewall.conf.
+- INPUT or FORWARD - +The packet has a source IP address that isn't in any of your +defined zones ("shorewall check" and look at the printed zone +definitions) or the chain is FORWARD and the destination IP isn't +in any of your defined zones.
+- logflags - The packet is being logged + because it failed the checks implemented by the tcpflags interface option.
- +
-18. Is there any way to use aliased ip addresses - with Shorewall, and maintain separate rulesets for different - IPs?
- Answer: Yes. You simply use the IP address - in your rules (or if you use NAT, use the local IP address in - your rules). Note: The ":n" notation (e.g., eth0:0) is deprecated - and will disappear eventually. Neither iproute (ip and tc) nor - iptables supports that notation so neither does Shorewall.
-
- Example 1:
-
- /etc/shorewall/rules - + +18. Is there any way to use aliased ip addresses + with Shorewall, and maintain separate rulesets for different + IPs?
+ Answer: Yes. You simply use the IP +address in your rules (or if you use NAT, use the local IP address +in your rules). Note: The ":n" notation (e.g., eth0:0) +is deprecated and will disappear eventually. Neither iproute + (ip and tc) nor iptables supports that notation so neither does + Shorewall.
+
+ Example 1:
+
+ /etc/shorewall/rules +# Accept AUTH but only on address 192.0.2.125- Example - 2 (NAT):
ACCEPT net fw:192.0.2.125 tcp auth
-
- /etc/shorewall/nat
- + Example + 2 (NAT):
+
+ /etc/shorewall/nat
+192.0.2.126 eth0 10.1.1.126- /etc/shorewall/rules - + /etc/shorewall/rules +# Accept HTTP on 192.0.2.126 (a.k.a. 10.1.1.126)- Example 3 (DNAT):
ACCEPT net loc:10.1.1.126 tcp www
- + Example 3 (DNAT):
+# Forward SMTP on external address 192.0.2.127 to local system 10.1.1.127+ +
DNAT net loc:10.1.1.127 tcp smtp - 192.0.2.12719. I have added entries to /etc/shorewall/tcrules + but they don't seem to do anything. Why?
+ You probably haven't set TC_ENABLED=Yes in /etc/shorewall/shorewall.conf + so the contents of the tcrules file are simply being ignored.
+ +20. I have just set up a server. Do I have + to change Shorewall to allow access to my server from the internet?
+ Yes. Consult the QuickStart guide that you +used during your initial setup for information about how to set up +rules for your server.
+
-19. I have added entries to /etc/shorewall/tcrules - but they don't seem to do anything. Why?
- You probably haven't set TC_ENABLED=Yes in /etc/shorewall/shorewall.conf - so the contents of the tcrules file are simply being ignored.
- -20. I have just set up a server. Do I have - to change Shorewall to allow access to my server from the internet?
- Yes. Consult the QuickStart guide that -you used during your initial setup for information about how to set - up rules for your server.
-
- -21. I see these strange log entries occasionally; - what are they?
- -
-- ++ 192.0.2.3 is external on my firewall... 172.16.0.0/24 + is my internal LAN21. I see these strange log entries occasionally; + what are they?
+ +
++- 192.0.2.3 is external on my firewall... 172.16.0.0/24 - is my internal LANNov 25 18:58:52 linux kernel: Shorewall:net2all:DROP:IN=eth1 OUT= MAC=00:60:1d:f0:a6:f9:00:60:1d:f6:35:50:08:00-
SRC=206.124.146.179 DST=192.0.2.3 LEN=56 TOS=0x00 PREC=0x00 TTL=110 ID=18558 PROTO=ICMP TYPE=3 CODE=3
[SRC=192.0.2.3 DST=172.16.1.10 LEN=128 TOS=0x00 PREC=0x00 TTL=47 ID=0 DF PROTO=UDP SPT=53 DPT=2857 LEN=108 ]
-
- Answer: While most people associate the Internet - Control Message Protocol (ICMP) with 'ping', ICMP is a key piece - of the internet. ICMP is used to report problems back to the sender - of a packet; this is what is happening here. Unfortunately, where NAT - is involved (including SNAT, DNAT and Masquerade), there are a lot -of broken implementations. That is what you are seeing with these messages.
-
- Here is my interpretation of what is happening -- to -confirm this analysis, one would have to have packet sniffers placed -a both ends of the connection.
-
- Host 172.16.1.10 behind NAT gateway 206.124.146.179 -sent a UDP DNS query to 192.0.2.3 and your DNS server tried to -send a response (the response information is in the brackets -- note -source port 53 which marks this as a DNS reply). When the response was -returned to to 206.124.146.179, it rewrote the destination IP TO 172.16.1.10 -and forwarded the packet to 172.16.1.10 who no longer had a connection -on UDP port 2857. This causes a port unreachable (type 3, code 3) to -be generated back to 192.0.2.3. As this packet is sent back through 206.124.146.179, - that box correctly changes the source address in the packet to 206.124.146.179 - but doesn't reset the DST IP in the original DNS response similarly. - When the ICMP reaches your firewall (192.0.2.3), your firewall has -no record of having sent a DNS reply to 172.16.1.10 so this ICMP doesn't - appear to be related to anything that was sent. The final result is - that the packet gets logged and dropped in the all2all chain. I have also - seen cases where the source IP in the ICMP itself isn't set back to the - external IP of the remote NAT gateway; that causes your firewall to log - and drop the packet out of the rfc1918 chain because the source IP is - reserved by RFC 1918.
- -22. I have some iptables commands that - I want to run when Shorewall starts. Which file do I put them - in?
- You can place these commands in one of the Shorewall Extension Scripts. -Be sure that you look at the contents of the chain(s) that you will be modifying - with your commands to be sure that the commands will do what they -are intended. Many iptables commands published in HOWTOs and other -instructional material use the -A command which adds the rules to the -end of the chain. Most chains that Shorewall constructs end with an -unconditional DROP, ACCEPT or REJECT rule and any rules that you add -after that will be ignored. Check "man iptables" and look at the -I (--insert) -command.
+
+
+ Answer: While most people associate the Internet + Control Message Protocol (ICMP) with 'ping', ICMP is a key piece + of the internet. ICMP is used to report problems back to the sender + of a packet; this is what is happening here. Unfortunately, where +NAT is involved (including SNAT, DNAT and Masquerade), there are +a lot of broken implementations. That is what you are seeing with these +messages.
+
+ Here is my interpretation of what is happening -- +to confirm this analysis, one would have to have packet sniffers +placed a both ends of the connection.
+
+ Host 172.16.1.10 behind NAT gateway 206.124.146.179 + sent a UDP DNS query to 192.0.2.3 and your DNS server tried to +send a response (the response information is in the brackets -- note +source port 53 which marks this as a DNS reply). When the response was +returned to to 206.124.146.179, it rewrote the destination IP TO 172.16.1.10 + and forwarded the packet to 172.16.1.10 who no longer had a connection + on UDP port 2857. This causes a port unreachable (type 3, code 3) +to be generated back to 192.0.2.3. As this packet is sent back through + 206.124.146.179, that box correctly changes the source address in +the packet to 206.124.146.179 but doesn't reset the DST IP in the original + DNS response similarly. When the ICMP reaches your firewall (192.0.2.3), + your firewall has no record of having sent a DNS reply to 172.16.1.10 +so this ICMP doesn't appear to be related to anything that was sent. +The final result is that the packet gets logged and dropped in the +all2all chain. I have also seen cases where the source IP in the ICMP +itself isn't set back to the external IP of the remote NAT gateway; that +causes your firewall to log and drop the packet out of the rfc1918 chain +because the source IP is reserved by RFC 1918.
+ +22. I have some iptables commands that + I want to run when Shorewall starts. Which file do I put them + in?
+ You can place these commands in one of the Shorewall Extension Scripts. Be +sure that you look at the contents of the chain(s) that you will be modifying + with your commands to be sure that the commands will do what they +are intended. Many iptables commands published in HOWTOs and other instructional + material use the -A command which adds the rules to the end of the +chain. Most chains that Shorewall constructs end with an unconditional +DROP, ACCEPT or REJECT rule and any rules that you add after that will +be ignored. Check "man iptables" and look at the -I (--insert) command.
+ +23. Why do you use such ugly fonts on your + web site?
+ The Shorewall web site is almost font neutral (it doesn't +explicitly specify fonts except on a few pages) so the fonts you see +are largely the default fonts configured in your browser. If you don't +like them then reconfigure your browser.
+ +24. How can I allow conections to let's say + the ssh port only from specific IP Addresses on the internet?
+ In the SOURCE column of the rule, follow "net" by a colon and +a list of the host/subnet addresses as a comma-separated list.
-23. Why do you use such ugly fonts on your - web site?
- The Shorewall web site is almost font neutral (it doesn't explicitly - specify fonts except on a few pages) so the fonts you see are largely - the default fonts configured in your browser. If you don't like them -then reconfigure your browser.
- -24. How can I allow conections to let's say - the ssh port only from specific IP Addresses on the internet?
- In the SOURCE column of the rule, follow "net" by a colon and a -list of the host/subnet addresses as a comma-separated list.
-net:<ip1>,<ip2>,...- Example:
- + Example:
+ACCEPT net:192.0.2.16/28,192.0.2.44 fw tcp 22+ - +- Last updated 2/6/2003 - Tom Eastep - -Copyright -© 2001, 2002, 2003 Thomas M. Eastep.
+ Last updated 2/18/2003 - Tom Eastep + +
-Copyright © +2001, 2002, 2003 Thomas M. Eastep.
+
+
+
+
diff --git a/Shorewall-docs/MAC_Validation.html b/Shorewall-docs/MAC_Validation.html index c4770f15b..76184b5cc 100644 --- a/Shorewall-docs/MAC_Validation.html +++ b/Shorewall-docs/MAC_Validation.html @@ -2,110 +2,109 @@MAC Verification - + - + - +- -
-- +- + + - - + ++ -MAC Verification
-
-
-
+ + + +
- Beginning with Shorewall version 1.3.10, all traffic from an interface - or from a subnet on an interface can be verified to originate from a defined - set of MAC addresses. Furthermore, each MAC address may be optionally -associated with one or more IP addresses.
-
- You must have the iproute package (ip utility) installed to use MAC -Verification and your kernel must include MAC match support (CONFIG_IP_NF_MATCH_MAC +
+ Beginning with Shorewall version 1.3.10, all traffic from an interface + or from a subnet on an interface can be verified to originate from a defined + set of MAC addresses. Furthermore, each MAC address may be optionally associated + with one or more IP addresses.
+
+ You must have the iproute package (ip utility) installed to use MAC +Verification and your kernel must include MAC match support (CONFIG_IP_NF_MATCH_MAC - module name ipt_mac.o).
-
- There are four components to this facility.
- +
+ There are four components to this facility.
+-
- The columns in /etc/shorewall/maclist are:- The maclist interface option in /etc/shorewall/interfaces. When -this option is specified, all traffic arriving on the interface is subjet -to MAC verification.
-- The maclist option in /etc/shorewall/hosts. When this option -is specified for a subnet, all traffic from that subnet is subject to MAC +
- The maclist interface option in /etc/shorewall/interfaces. When this +option is specified, all traffic arriving on the interface is subjet to MAC verification.
-- The /etc/shorewall/maclist file. This file is used to associate - MAC addresses with interfaces and to optionally associate IP addresses with - MAC addresses.
-- The MACLIST_DISPOSITION and MACLIST_LOG_LEVEL variables - in /etc/shorewall/shorewall.conf. -The MACLIST_DISPOSITION variable has the value DROP, REJECT or ACCEPT and -determines the disposition of connection requests that fail MAC verification. -The MACLIST_LOG_LEVEL variable gives the syslogd level at which connection -requests that fail verification are to be logged. If set the the empty value +
- The maclist option in /etc/shorewall/hosts. When this option + is specified for a subnet, all traffic from that subnet is subject to MAC + verification.
+- The /etc/shorewall/maclist file. This file is used to associate + MAC addresses with interfaces and to optionally associate IP addresses +with MAC addresses.
+- The MACLIST_DISPOSITION and MACLIST_LOG_LEVEL variables + in /etc/shorewall/shorewall.conf. +The MACLIST_DISPOSITION variable has the value DROP, REJECT or ACCEPT and +determines the disposition of connection requests that fail MAC verification. +The MACLIST_LOG_LEVEL variable gives the syslogd level at which connection +requests that fail verification are to be logged. If set the the empty value (e.g., MACLIST_LOG_LEVEL="") then failing connection requests are not logged.
- + +
-
- + The columns in /etc/shorewall/maclist are:
+-
- +- INTERFACE - The name of an ethernet interface on the Shorewall +
- INTERFACE - The name of an ethernet interface on the Shorewall system.
-- MAC - The MAC address of a device on the ethernet segment connected - by INTERFACE. It is not necessary to use the Shorewall MAC format in this +
- MAC - The MAC address of a device on the ethernet segment connected + by INTERFACE. It is not necessary to use the Shorewall MAC format in this column although you may use that format if you so choose.
-- IP Address - An optional comma-separated list of IP addresses -for the device whose MAC is listed in the MAC column.
- +- IP Address - An optional comma-separated list of IP addresses + for the device whose MAC is listed in the MAC column.
+Example 1: Here are my files:
- /etc/shorewall/shorewall.conf:
- + /etc/shorewall/shorewall.conf:
+MACLIST_DISPOSITION=REJECT- /etc/shorewall/interfaces:
MACLIST_LOG_LEVEL=info
- -#ZONE INTERFACE BROADCAST OPTIONS- /etc/shorewall/maclist:
net eth0 206.124.146.255 norfc1918,filterping,dhcp,blacklist
loc eth2 192.168.1.255 dhcp,filterping,maclist
dmz eth1 192.168.2.255 filterping
net eth3 206.124.146.255 filterping,blacklist
- texas 192.168.9.255 filterping
loc ppp+ - filterping
- + /etc/shorewall/interfaces:
+ +#ZONE INTERFACE BROADCAST OPTIONS+ /etc/shorewall/maclist:
net eth0 206.124.146.255 norfc1918,dhcp,blacklist
loc eth2 192.168.1.255 dhcp,maclist
dmz eth1 192.168.2.255
net eth3 206.124.146.255 blacklist
- texas 192.168.9.255
loc ppp+
+#INTERFACE MAC IP ADDRESSES (Optional)- As shown above, I use MAC Verification on my -local zone.
eth2 00:A0:CC:63:66:89 192.168.1.3 #Wookie
eth2 00:10:B5:EC:FD:0B 192.168.1.4 #Tarry
eth2 00:A0:CC:DB:31:C4 192.168.1.5 #Ursa
eth2 00:A0:CC:DB:31:C4 192.168.1.128/26 #PPTP Clients to server on Ursa
eth2 00:06:25:aa:a8:0f 192.168.1.7 #Eastept1 (Wireless)
eth2 00:04:5A:0E:85:B9 192.168.1.250 #Wap
- + As shown above, I use MAC Verification on my local zone.
+Example 2: Router in Local Zone
- Suppose now that I add a second ethernet segment to my local zone and - gateway that segment via a router with MAC address 00:06:43:45:C6:15 and - IP address 192.168.1.253. Hosts in the second segment have IP addresses -in the subnet 192.168.2.0/24. I would add the following entry to my /etc/shorewall/maclist + Suppose now that I add a second ethernet segment to my local zone +and gateway that segment via a router with MAC address 00:06:43:45:C6:15 +and IP address 192.168.1.253. Hosts in the second segment have IP addresses + in the subnet 192.168.2.0/24. I would add the following entry to my /etc/shorewall/maclist file:
- +eth2 00:06:43:45:C6:15 192.168.1.253,192.168.2.0/24- This entry accomodates traffic from the router itself (192.168.1.253) - and from the second LAN segment (192.168.2.0/24). Remember that all traffic - being sent to my firewall from the 192.168.2.0/24 segment will be forwarded - by the router so that traffic's MAC address will be that of the router -(00:06:43:45:C6:15) and not that of the host sending the traffic. - -Updated 1/7/2002 - Tom Eastep -
+ This entry accomodates traffic from the router itself (192.168.1.253) + and from the second LAN segment (192.168.2.0/24). Remember that all traffic + being sent to my firewall from the 192.168.2.0/24 segment will be forwarded + by the router so that traffic's MAC address will be that of the router (00:06:43:45:C6:15) + and not that of the host sending the traffic. +Updated 2/18/2002 - Tom Eastep +
- - +
diff --git a/Shorewall-docs/News.htm b/Shorewall-docs/News.htm index e27dd03e3..35e3ef5b0 100644 --- a/Shorewall-docs/News.htm +++ b/Shorewall-docs/News.htm @@ -3,2158 +3,2293 @@ - +Shorewall News - + + - + - +- -
- -- ++ + + + - - + +- + + -Shorewall News Archive
-2/8/2003 - Shoreawll 1.3.14
+ +3/14/2003 - Shorewall 1.4.0
+ Shorewall 1.4 represents the next + step in the evolution of Shorewall. The main thrust of the initial release + is simply to remove the cruft that has accumulated in Shorewall over time. +
+ Function from 1.3 that has been omitted from this version include:
+ ++
+ Changes for 1.4 include:- The MERGE_HOSTS variable in shorewall.conf is no longer supported. +Shorewall 1.4 behavior is the same as 1.3 with MERGE_HOSTS=Yes.
+
+
+- Interface names of the form <device>:<integer> in /etc/shorewall/interfaces + now generate an error.
+
+
+- Shorewall 1.4 implements behavior consistent with OLD_PING_HANDLING=No. + OLD_PING_HANDLING=Yes will generate an error at startup as will specification + of the 'noping' or 'filterping' interface options.
+
+
+- The 'routestopped' option in the /etc/shorewall/interfaces and /etc/shorewall/hosts + files is no longer supported and will generate an error at startup if specified.
+
+
+- The Shorewall 1.2 syntax for DNAT and REDIRECT rules is no longer +accepted.
+
+
+- The ALLOWRELATED variable in shorewall.conf is no longer supported. + Shorewall 1.4 behavior is the same as 1.3 with ALLOWRELATED=Yes.
+
+
+- The icmp.def file has been removed.
+ +
+
+ ++
+ +- The /etc/shorewall/shorewall.conf file has been completely reorganized + into logical sections.
+
+
+- LOG is now a valid action for a rule (/etc/shorewall/rules).
+
+
+- The firewall script and version file are now installed in /usr/share/shorewall.
+
+
+- Late arriving DNS replies are now silently dropped in the common +chain by default.
+
+
+- In addition to behaving like OLD_PING_HANDLING=No, Shorewall 1.4 +no longer unconditionally accepts outbound ICMP packets. So if you want +to 'ping' from the firewall, you will need the appropriate rule or policy. +
+ +2/8/2003 - Shoreawall 1.3.14
+New features include
+-
-- An OLD_PING_HANDLING option has been added to shorewall.conf. When - set to Yes, Shorewall ping handling is as it has always been (see http://www.shorewall.net/ping.html).
-
-
- When OLD_PING_HANDLING=No, icmp echo (ping) is handled via rules and -policies just like any other connection request. The FORWARDPING=Yes option -in shorewall.conf and the 'noping' and 'filterping' options in /etc/shorewall/interfaces -will all generate an error.
-
-- It is now possible to direct Shorewall to create a "label" such as - "eth0:0" for IP addresses that it creates under ADD_IP_ALIASES=Yes and ADD_SNAT_ALIASES=Yes. - This is done by specifying the label instead of just the interface name:
-
-
- a) In the INTERFACE column of /etc/shorewall/masq
- b) In the INTERFACE column of /etc/shorewall/nat
-- Support for OpenVPN Tunnels.
-
-
-- Support for VLAN devices with names of the form $DEV.$VID (e.g., eth0.0)
-
-
-- When an interface name is entered in the SUBNET column of the /etc/shorewall/masq - file, Shorewall previously masqueraded traffic from only the first subnet - defined on that interface. It did not masquerade traffic from:
-
-
- a) The subnets associated with other addresses on the interface.
- b) Subnets accessed through local routers.
-
- Beginning with Shorewall 1.3.14, if you enter an interface name in the - SUBNET column, shorewall will use the firewall's routing table to construct - the masquerading/SNAT rules.
-
- Example 1 -- This is how it works in 1.3.14.
-
- -[root@gateway test]# cat /etc/shorewall/masq- -
#INTERFACE SUBNET ADDRESS
eth0 eth2 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE[root@gateway test]# ip route show dev eth2- -
192.168.1.0/24 scope link
192.168.10.0/24 proto kernel scope link src 192.168.10.254[root@gateway test]# shorewall start-
...
Masqueraded Subnets and Hosts:
To 0.0.0.0/0 from 192.168.1.0/24 through eth0 using 206.124.146.176
To 0.0.0.0/0 from 192.168.10.0/24 through eth0 using 206.124.146.176
Processing /etc/shorewall/tos...
- When upgrading to Shorewall 1.3.14, if you have multiple local subnets - connected to an interface that is specified in the SUBNET column of an /etc/shorewall/masq - entry, your /etc/shorewall/masq file will need changing. In most cases, -you will simply be able to remove redundant entries. In some cases though, -you might want to change from using the interface name to listing specific -subnetworks if the change described above will cause masquerading to occur -on subnetworks that you don't wish to masquerade.
-
- Example 2 -- Suppose that your current config is as follows:
-
- -[root@gateway test]# cat /etc/shorewall/masq- -
#INTERFACE SUBNET ADDRESS
eth0 eth2 206.124.146.176
eth0 192.168.10.0/24 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE[root@gateway test]# ip route show dev eth2-
192.168.1.0/24 scope link
192.168.10.0/24 proto kernel scope link src 192.168.10.254
[root@gateway test]#
- In this case, the second entry in /etc/shorewall/masq is no longer - required.
-
- Example 3 -- What if your current configuration is like this?
-
- -[root@gateway test]# cat /etc/shorewall/masq- -
#INTERFACE SUBNET ADDRESS
eth0 eth2 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE[root@gateway test]# ip route show dev eth2-
192.168.1.0/24 scope link
192.168.10.0/24 proto kernel scope link src 192.168.10.254
[root@gateway test]#
- In this case, you would want to change the entry in /etc/shorewall/masq - to:
- -#INTERFACE SUBNET ADDRESS-
eth0 192.168.1.0/24 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE- -
-2/5/2003 - Shorewall Support included in Webmin 1.060Webmin version 1.060 now has Shorewall support included as standard. See -http://www.webmin.com.
- -
-
- 2/4/2003 - Shorewall 1.3.14-RC1Includes the Beta 2 content plus support for OpenVPN tunnels.
- -1/28/2003 - Shorewall 1.3.14-Beta2
- -Includes the Beta 1 content plus restores VLAN device names of the form - $dev.$vid (e.g., eth0.1)
- -1/25/2003 - Shorewall 1.3.14-Beta1
- -
-The Beta includes the following changes:
- -
--
- + +- An OLD_PING_HANDLING option has been added to shorewall.conf. -When set to Yes, Shorewall ping handling is as it has always been (see +
- An OLD_PING_HANDLING option has been added to shorewall.conf. +When set to Yes, Shorewall ping handling is as it has always been (see http://www.shorewall.net/ping.html).
-
-
- When OLD_PING_HANDLING=No, icmp echo (ping) is handled via rules and -policies just like any other connection request. The FORWARDPING=Yes option -in shorewall.conf and the 'noping' and 'filterping' options in /etc/shorewall/interfaces -will all generate an error.
-
-- It is now possible to direct Shorewall to create a "label" such - as "eth0:0" for IP addresses that it creates under ADD_IP_ALIASES=Yes -and ADD_SNAT_ALIASES=Yes. This is done by specifying the label instead -of just the interface name:
-
-
- a) In the INTERFACE column of /etc/shorewall/masq
- b) In the INTERFACE column of /etc/shorewall/nat
-- When an interface name is entered in the SUBNET column of the -/etc/shorewall/masq file, Shorewall previously masqueraded traffic from -only the first subnet defined on that interface. It did not masquerade +
+
+ When OLD_PING_HANDLING=No, icmp echo (ping) is handled via rules + and policies just like any other connection request. The FORWARDPING=Yes + option in shorewall.conf and the 'noping' and 'filterping' options in + /etc/shorewall/interfaces will all generate an error.
+
+- It is now possible to direct Shorewall to create a "label" such + as "eth0:0" for IP addresses that it creates under ADD_IP_ALIASES=Yes + and ADD_SNAT_ALIASES=Yes. This is done by specifying the label instead + of just the interface name:
+
+
+ a) In the INTERFACE column of /etc/shorewall/masq
+ b) In the INTERFACE column of /etc/shorewall/nat
+- Support for OpenVPN Tunnels.
+
+
+- Support for VLAN devices with names of the form $DEV.$VID (e.g., + eth0.0)
+
+
+- In /etc/shorewall/tcrules, the MARK value may be optionally followed + by ":" and either 'F' or 'P' to designate that the marking will occur in + the FORWARD or PREROUTING chains respectively. If this additional specification + is omitted, the chain used to mark packets will be determined by the setting + of the MARK_IN_FORWARD_CHAIN option in shorewall.conf.
+
+
+- When an interface name is entered in the SUBNET column of the +/etc/shorewall/masq file, Shorewall previously masqueraded traffic from +only the first subnet defined on that interface. It did not masquerade traffic from:
- + +
-
- a) The subnets associated with other addresses on the interface.
- b) Subnets accessed through local routers.
-
- Beginning with Shorewall 1.3.14, if you enter an interface name in the - SUBNET column, shorewall will use the firewall's routing table to construct - the masquerading/SNAT rules.
-
- Example 1 -- This is how it works in 1.3.14.
-
- +
+ a) The subnets associated with other addresses on the interface.
+ b) Subnets accessed through local routers.
+
+ Beginning with Shorewall 1.3.14, if you enter an interface name + in the SUBNET column, shorewall will use the firewall's routing table + to construct the masquerading/SNAT rules.
+
+ Example 1 -- This is how it works in 1.3.14.
+
+[root@gateway test]# cat /etc/shorewall/masq- +
#INTERFACE SUBNET ADDRESS
eth0 eth2 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE[root@gateway test]# ip route show dev eth2- +
192.168.1.0/24 scope link
192.168.10.0/24 proto kernel scope link src 192.168.10.254[root@gateway test]# shorewall start-
...
Masqueraded Subnets and Hosts:
To 0.0.0.0/0 from 192.168.1.0/24 through eth0 using 206.124.146.176
To 0.0.0.0/0 from 192.168.10.0/24 through eth0 using 206.124.146.176
Processing /etc/shorewall/tos...
- When upgrading to Shorewall 1.3.14, if you have multiple local subnets - connected to an interface that is specified in the SUBNET column of an /etc/shorewall/masq - entry, your /etc/shorewall/masq file will need changing. In most cases, -you will simply be able to remove redundant entries. In some cases though, -you might want to change from using the interface name to listing specific -subnetworks if the change described above will cause masquerading to occur -on subnetworks that you don't wish to masquerade.
-
- Example 2 -- Suppose that your current config is as follows:
-
- +
+ When upgrading to Shorewall 1.3.14, if you have multiple local +subnets connected to an interface that is specified in the SUBNET column +of an /etc/shorewall/masq entry, your /etc/shorewall/masq file will need +changing. In most cases, you will simply be able to remove redundant entries. +In some cases though, you might want to change from using the interface +name to listing specific subnetworks if the change described above will cause +masquerading to occur on subnetworks that you don't wish to masquerade.
+
+ Example 2 -- Suppose that your current config is as follows:
+
+[root@gateway test]# cat /etc/shorewall/masq- +
#INTERFACE SUBNET ADDRESS
eth0 eth2 206.124.146.176
eth0 192.168.10.0/24 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE[root@gateway test]# ip route show dev eth2-
192.168.1.0/24 scope link
192.168.10.0/24 proto kernel scope link src 192.168.10.254
[root@gateway test]#
- In this case, the second entry in /etc/shorewall/masq is no longer - required.
-
- Example 3 -- What if your current configuration is like this?
-
- +
+ In this case, the second entry in /etc/shorewall/masq is no +longer required.
+
+ Example 3 -- What if your current configuration is like this?
+
+[root@gateway test]# cat /etc/shorewall/masq- +
#INTERFACE SUBNET ADDRESS
eth0 eth2 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE[root@gateway test]# ip route show dev eth2-
192.168.1.0/24 scope link
192.168.10.0/24 proto kernel scope link src 192.168.10.254
[root@gateway test]#
- In this case, you would want to change the entry in /etc/shorewall/masq - to:
- +
+ In this case, you would want to change the entry in /etc/shorewall/masq + to:
+#INTERFACE SUBNET ADDRESS-
eth0 192.168.1.0/24 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE+ +
+ 2/5/2003 - Shorewall Support included in Webmin 1.060Webmin version 1.060 now has Shorewall support included as standard. See + http://www.webmin.com.
+ +
+
+ 2/4/2003 - Shorewall 1.3.14-RC1Includes the Beta 2 content plus support for OpenVPN tunnels.
+ +1/28/2003 - Shorewall 1.3.14-Beta2
+ +Includes the Beta 1 content plus restores VLAN device names of the form + $dev.$vid (e.g., eth0.1)
+ +1/25/2003 - Shorewall 1.3.14-Beta1
+ +
+The Beta includes the following changes:
+ +
++
+- An OLD_PING_HANDLING option has been added to shorewall.conf. + When set to Yes, Shorewall ping handling is as it has always been (see + http://www.shorewall.net/ping.html).
+
+
+ When OLD_PING_HANDLING=No, icmp echo (ping) is handled via rules + and policies just like any other connection request. The FORWARDPING=Yes + option in shorewall.conf and the 'noping' and 'filterping' options in + /etc/shorewall/interfaces will all generate an error.
+
+- It is now possible to direct Shorewall to create a "label" + such as "eth0:0" for IP addresses that it creates under ADD_IP_ALIASES=Yes + and ADD_SNAT_ALIASES=Yes. This is done by specifying the label instead + of just the interface name:
+
+
+ a) In the INTERFACE column of /etc/shorewall/masq
+ b) In the INTERFACE column of /etc/shorewall/nat
+- When an interface name is entered in the SUBNET column of + the /etc/shorewall/masq file, Shorewall previously masqueraded traffic + from only the first subnet defined on that interface. It did not masquerade + traffic from:
+ +
+
+ a) The subnets associated with other addresses on the interface.
+ b) Subnets accessed through local routers.
+
+ Beginning with Shorewall 1.3.14, if you enter an interface name + in the SUBNET column, shorewall will use the firewall's routing table + to construct the masquerading/SNAT rules.
+
+ Example 1 -- This is how it works in 1.3.14.
+
+ +[root@gateway test]# cat /etc/shorewall/masq+ +
#INTERFACE SUBNET ADDRESS
eth0 eth2 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE[root@gateway test]# ip route show dev eth2+ +
192.168.1.0/24 scope link
192.168.10.0/24 proto kernel scope link src 192.168.10.254[root@gateway test]# shorewall start+
...
Masqueraded Subnets and Hosts:
To 0.0.0.0/0 from 192.168.1.0/24 through eth0 using 206.124.146.176
To 0.0.0.0/0 from 192.168.10.0/24 through eth0 using 206.124.146.176
Processing /etc/shorewall/tos...
+ When upgrading to Shorewall 1.3.14, if you have multiple local +subnets connected to an interface that is specified in the SUBNET column +of an /etc/shorewall/masq entry, your /etc/shorewall/masq file will need +changing. In most cases, you will simply be able to remove redundant entries. +In some cases though, you might want to change from using the interface +name to listing specific subnetworks if the change described above will cause +masquerading to occur on subnetworks that you don't wish to masquerade.
+
+ Example 2 -- Suppose that your current config is as follows:
+
+ +[root@gateway test]# cat /etc/shorewall/masq+ +
#INTERFACE SUBNET ADDRESS
eth0 eth2 206.124.146.176
eth0 192.168.10.0/24 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE[root@gateway test]# ip route show dev eth2+
192.168.1.0/24 scope link
192.168.10.0/24 proto kernel scope link src 192.168.10.254
[root@gateway test]#
+ In this case, the second entry in /etc/shorewall/masq is no +longer required.
+
+ Example 3 -- What if your current configuration is like this?
+
+ +[root@gateway test]# cat /etc/shorewall/masq+ +
#INTERFACE SUBNET ADDRESS
eth0 eth2 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE[root@gateway test]# ip route show dev eth2+
192.168.1.0/24 scope link
192.168.10.0/24 proto kernel scope link src 192.168.10.254
[root@gateway test]#
+ In this case, you would want to change the entry in /etc/shorewall/masq + to:
+ +#INTERFACE SUBNET ADDRESS+
eth0 192.168.1.0/24 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE1/18/2003 - Shorewall 1.3.13 Documentation in PDF Format
- +Juraj Ontkanin has produced a PDF containing the Shorewall 1.3.13 documenation. - the PDF may be downloaded from
- + ftp://slovakia.shorewall.net/mirror/shorewall/pdf/
- http://slovakia.shorewall.net/pub/shorewall/pdf/ - -1/17/2003 - shorewall.net has MOVED
+1/17/2003 - shorewall.net has MOVED
+Thanks to the generosity of Alex Martin and Rett Consulting, www.shorewall.net and ftp.shorewall.net are now hosted on a system in Bellevue, Washington. A big thanks to Alex for making this happen.
- + +
-1/13/2003 - Shorewall 1.3.13
- + +
-Just includes a few things that I had on the burner:
- + +
--
- +- A new 'DNAT-' action has been added for entries in the /etc/shorewall/rules - file. DNAT- is intended for advanced users who wish to minimize the number - of rules that connection requests must traverse.
-
-
- A Shorewall DNAT rule actually generates two iptables rules: a header - rewriting rule in the 'nat' table and an ACCEPT rule in the 'filter' -table. A DNAT- rule only generates the first of these rules. This is -handy when you have several DNAT rules that would generate the same ACCEPT -rule.
-
- Here are three rules from my previous rules file:
-
- DNAT net dmz:206.124.146.177 tcp smtp - 206.124.146.178
- DNAT net dmz:206.124.146.177 tcp smtp - 206.124.146.179
- ACCEPT net dmz:206.124.146.177 tcp www,smtp,ftp,...
-
- These three rules ended up generating _three_ copies of
-
- ACCEPT net dmz:206.124.146.177 tcp smtp
-
- By writing the rules this way, I end up with only one copy of -the ACCEPT rule.
-
- DNAT- net dmz:206.124.146.177 tcp smtp - 206.124.146.178
- DNAT- net dmz:206.124.146.177 tcp smtp - 206.124.146.179
- ACCEPT net dmz:206.124.146.177 tcp www,smtp,ftp,....
-
-- The 'shorewall check' command now prints out the applicable - policy between each pair of zones.
-
-
-- A new CLEAR_TC option has been added to shorewall.conf. If -this option is set to 'No' then Shorewall won't clear the current traffic -control rules during [re]start. This setting is intended for use by people -that prefer to configure traffic shaping when the network interfaces come -up rather than when the firewall is started. If that is what you want to -do, set TC_ENABLED=Yes and CLEAR_TC=No and do not supply an /etc/shorewall/tcstart - file. That way, your traffic shaping rules can still use the 'fwmark' -classifier based on packet marking defined in /etc/shorewall/tcrules.
-
-
-- A new SHARED_DIR variable has been added that allows distribution - packagers to easily move the shared directory (default /usr/lib/shorewall). - Users should never have a need to change the value of this shorewall.conf - setting.
- +
-- A new 'DNAT-' action has been added for entries in the + /etc/shorewall/rules file. DNAT- is intended for advanced users who + wish to minimize the number of rules that connection requests must traverse.
+
+
+ A Shorewall DNAT rule actually generates two iptables rules: + a header rewriting rule in the 'nat' table and an ACCEPT rule in the + 'filter' table. A DNAT- rule only generates the first of these rules. + This is handy when you have several DNAT rules that would generate the + same ACCEPT rule.
+
+ Here are three rules from my previous rules file:
+
+ DNAT net dmz:206.124.146.177 tcp smtp - 206.124.146.178
+ DNAT net dmz:206.124.146.177 tcp smtp - 206.124.146.179
+ ACCEPT net dmz:206.124.146.177 tcp www,smtp,ftp,...
+
+ These three rules ended up generating _three_ copies of
+
+ ACCEPT net dmz:206.124.146.177 tcp smtp
+
+ By writing the rules this way, I end up with only one copy + of the ACCEPT rule.
+
+ DNAT- net dmz:206.124.146.177 tcp smtp - 206.124.146.178
+ DNAT- net dmz:206.124.146.177 tcp smtp - 206.124.146.179
+ ACCEPT net dmz:206.124.146.177 tcp www,smtp,ftp,....
+
+- The 'shorewall check' command now prints out the applicable + policy between each pair of zones.
+
+
+- A new CLEAR_TC option has been added to shorewall.conf. + If this option is set to 'No' then Shorewall won't clear the current + traffic control rules during [re]start. This setting is intended for +use by people that prefer to configure traffic shaping when the network +interfaces come up rather than when the firewall is started. If that is +what you want to do, set TC_ENABLED=Yes and CLEAR_TC=No and do not supply +an /etc/shorewall/tcstart file. That way, your traffic shaping rules +can still use the 'fwmark' classifier based on packet marking defined +in /etc/shorewall/tcrules.
+
+
+- A new SHARED_DIR variable has been added that allows +distribution packagers to easily move the shared directory (default +/usr/lib/shorewall). Users should never have a need to change the value +of this shorewall.conf setting.
+
+1/6/2003 - BURNOUT
- +Until further notice, I will not be involved in either Shorewall Development - or Shorewall Support
- + or Shorewall Support +-Tom Eastep
- + +
-12/30/2002 - Shorewall Documentation in PDF Format
- +Juraj Ontkanin has produced a PDF containing the Shorewall 1.3.12 documenation. - the PDF may be downloaded from
- + the PDF may be downloaded from +ftp://slovakia.shorewall.net/mirror/shorewall/pdf/
- + +
- http://slovakia.shorewall.net/pub/shorewall/pdf/
-12/27/2002 - Shorewall 1.3.12 Released
- +Features include:
- + +
--
- +- "shorewall refresh" now reloads the traffic shaping rules - (tcrules and tcstart).
-- "shorewall debug [re]start" now turns off debugging after - an error occurs. This places the point of the failure near the end of - the trace rather than up in the middle of it.
-- "shorewall [re]start" has been speeded up by more than -40% with my configuration. Your milage may vary.
-- A "shorewall show classifiers" command has been added which - shows the current packet classification filters. The output from this - command is also added as a separate page in "shorewall monitor"
-- ULOG (must be all caps) is now accepted as a valid syslog - level and causes the subject packets to be logged using the ULOG target - rather than the LOG target. This allows you to run ulogd (available - from http://www.gnumonks.org/projects/ulogd) - and log all Shorewall messages to - a separate log file.
-- If you are running a kernel that has a FORWARD chain in -the mangle table ("shorewall show mangle" will show you the chains -in the mangle table), you can set MARK_IN_FORWARD_CHAIN=Yes in shorewall.conf. This allows for marking - input packets based on their destination even when you are using -Masquerading or SNAT.
-- I have cluttered up the /etc/shorewall directory with empty - 'init', 'start', 'stop' and 'stopped' files. If you already have a - file with one of these names, don't worry -- the upgrade process won't - overwrite your file.
-- I have added a new RFC1918_LOG_LEVEL variable to shorewall.conf. This variable specifies - the syslog level at which packets are logged as a result of entries -in the /etc/shorewall/rfc1918 file. Previously, these packets were always - logged at the 'info' level.
- +
-- "shorewall refresh" now reloads the traffic shaping + rules (tcrules and tcstart).
+- "shorewall debug [re]start" now turns off debugging + after an error occurs. This places the point of the failure near +the end of the trace rather than up in the middle of it.
+- "shorewall [re]start" has been speeded up by more +than 40% with my configuration. Your milage may vary.
+- A "shorewall show classifiers" command has been added + which shows the current packet classification filters. The output + from this command is also added as a separate page in "shorewall + monitor"
+- ULOG (must be all caps) is now accepted as a valid + syslog level and causes the subject packets to be logged using +the ULOG target rather than the LOG target. This allows you to run +ulogd (available from http://www.gnumonks.org/projects/ulogd) + and log all Shorewall messages to a separate log file.
+- If you are running a kernel that has a FORWARD chain + in the mangle table ("shorewall show mangle" will show you the +chains in the mangle table), you can set MARK_IN_FORWARD_CHAIN=Yes +in shorewall.conf. This allows for + marking input packets based on their destination even when you are +using Masquerading or SNAT.
+- I have cluttered up the /etc/shorewall directory +with empty 'init', 'start', 'stop' and 'stopped' files. If you +already have a file with one of these names, don't worry -- the upgrade +process won't overwrite your file.
+- I have added a new RFC1918_LOG_LEVEL variable to + shorewall.conf. This variable specifies + the syslog level at which packets are logged as a result of entries + in the /etc/shorewall/rfc1918 file. Previously, these packets were +always logged at the 'info' level.
+
+12/20/2002 - Shorewall 1.3.12 Beta 3
- This version corrects a problem with Blacklist logging. In Beta - 2, if BLACKLIST_LOG_LEVEL was set to anything but ULOG, the firewall -would fail to start and "shorewall refresh" would also fail.
-
- + + This version corrects a problem with Blacklist logging. + In Beta 2, if BLACKLIST_LOG_LEVEL was set to anything but ULOG, the + firewall would fail to start and "shorewall refresh" would also fail.
+12/20/2002 - Shorewall 1.3.12 Beta 2
- +The first public Beta version of Shorewall 1.3.12 is now available (Beta - 1 was made available only to a limited audience).
- Features include:
-
- + 1 was made available only to a limited audience).
+ + Features include:
+-
- You may download the Beta from:- "shorewall refresh" now reloads the traffic shaping - rules (tcrules and tcstart).
-- "shorewall debug [re]start" now turns off debugging - after an error occurs. This places the point of the failure near -the end of the trace rather than up in the middle of it.
-- "shorewall [re]start" has been speeded up by more -than 40% with my configuration. Your milage may vary.
-- A "shorewall show classifiers" command has been added - which shows the current packet classification filters. The output -from this command is also added as a separate page in "shorewall monitor"
-- ULOG (must be all caps) is now accepted as a valid -syslog level and causes the subject packets to be logged using the -ULOG target rather than the LOG target. This allows you to run ulogd -(available from http://www.gnumonks.org/projects/ulogd) - and log all Shorewall messages to - a separate log file.
-- If you are running a kernel that has a FORWARD chain - in the mangle table ("shorewall show mangle" will show you the chains - in the mangle table), you can set MARK_IN_FORWARD_CHAIN=Yes in shorewall.conf. - This allows for marking input packets based on their destination even - when you are using Masquerading or SNAT.
-- I have cluttered up the /etc/shorewall directory with - empty 'init', 'start', 'stop' and 'stopped' files. If you already -have a file with one of these names, don't worry -- the upgrade process -won't overwrite your file.
- +- "shorewall refresh" now reloads the traffic +shaping rules (tcrules and tcstart).
+- "shorewall debug [re]start" now turns off debugging + after an error occurs. This places the point of the failure near + the end of the trace rather than up in the middle of it.
+- "shorewall [re]start" has been speeded up by +more than 40% with my configuration. Your milage may vary.
+- A "shorewall show classifiers" command has been + added which shows the current packet classification filters. The + output from this command is also added as a separate page in "shorewall + monitor"
+- ULOG (must be all caps) is now accepted as a +valid syslog level and causes the subject packets to be logged using +the ULOG target rather than the LOG target. This allows you to +run ulogd (available from http://www.gnumonks.org/projects/ulogd) + and log all Shorewall messages to a separate log file.
+- If you are running a kernel that has a FORWARD + chain in the mangle table ("shorewall show mangle" will show you + the chains in the mangle table), you can set MARK_IN_FORWARD_CHAIN=Yes + in shorewall.conf. This allows for marking input packets based on +their destination even when you are using Masquerading or SNAT.
+- I have cluttered up the /etc/shorewall directory + with empty 'init', 'start', 'stop' and 'stopped' files. If you already + have a file with one of these names, don't worry -- the upgrade process + won't overwrite your file.
+
- + You may download the Beta from:
+http://www.shorewall.net/pub/shorewall/Beta- + ftp://ftp.shorewall.net/pub/shorewall/Beta
- ftp://ftp.shorewall.net/pub/shorewall/Beta
-
+ +12/12/2002 - Mandrake Multi Network Firewall
- Shorewall is at the center of MandrakeSoft's recently-announced - + Shorewall is at the center of MandrakeSoft's recently-announced + Multi - Network Firewall (MNF) product. Here is the product. Here is the press - release.-
- + release.
+12/7/2002 - Shorewall Support for Mandrake 9.0
- +Two months and 3 days after I ordered Mandrake 9.0, it was finally delivered. - I have installed 9.0 on one of my systems and I am now in a position - to support Shorewall users who run Mandrake 9.0.
- + I have installed 9.0 on one of my systems and I am now in a position + to support Shorewall users who run Mandrake 9.0. +12/6/2002 - Debian 1.3.11a Packages Available
+ - +
-Apt-get sources listed at http://security.dsi.unimi.it/~lorenzo/debian.html.
- +12/3/2002 - Shorewall 1.3.11a
- +This is a bug-fix roll up which includes Roger Aich's fix for DNAT with - excluded subnets (e.g., "DNAT foo!bar ..."). Current 1.3.11 users - who don't need rules of this type need not upgrade to 1.3.11.
- + excluded subnets (e.g., "DNAT foo!bar ..."). Current 1.3.11 +users who don't need rules of this type need not upgrade to 1.3.11. +11/24/2002 - Shorewall 1.3.11
- +In this version:
- +-
- +- A 'tcpflags' option has been added to entries - in /etc/shorewall/interfaces. - This option causes Shorewall to make a set of sanity check on TCP packet - header flags.
-- It is now allowed to use 'all' in the SOURCE - or DEST column in a rule. - When used, 'all' must appear by itself (in may not be qualified) and - it does not enable intra-zone traffic. For example, the rule
-
-
- ACCEPT loc all tcp 80
-
- does not enable http traffic from 'loc' to 'loc'.- Shorewall's use of the 'echo' command is now - compatible with bash clones such as ash and dash.
-- fw->fw policies now generate a startup error. - fw->fw rules generate a warning and are ignored
- +- A 'tcpflags' option has been added to +entries in /etc/shorewall/interfaces. + This option causes Shorewall to make a set of sanity check on TCP packet + header flags.
+- It is now allowed to use 'all' in the +SOURCE or DEST column in a rule. When used, 'all' must appear + by itself (in may not be qualified) and it does not enable intra-zone + traffic. For example, the rule
+
+
+ ACCEPT loc all tcp 80
+
+ does not enable http traffic from 'loc' to +'loc'.- Shorewall's use of the 'echo' command +is now compatible with bash clones such as ash and dash.
+- fw->fw policies now generate a startup + error. fw->fw rules generate a warning and are ignored
+11/14/2002 - Shorewall Documentation in PDF Format
- +Juraj Ontkanin has produced a PDF containing the Shorewall 1.3.10 documenation. - the PDF may be downloaded from
- + the PDF may be downloaded from +ftp://slovakia.shorewall.net/mirror/shorewall/pdf/
- + +
- http://slovakia.shorewall.net/pub/shorewall/pdf/
-11/09/2002 - Shorewall is Back at SourceForge
- +The main Shorewall 1.3 web site is now back at SourceForge at http://shorewall.sf.net.
+ - +
-11/09/2002 - Shorewall 1.3.10
- +In this version:
- +-
- +- You may now define - the contents of a zone dynamically with the "shorewall add" and "shorewall - delete" commands. These commands are expected to be used - primarily within You may now define the contents of a zone dynamically + with the "shorewall add" +and "shorewall delete" commands. These commands are expected + to be used primarily within FreeS/Wan updown scripts.
-- Shorewall can now doShorewall can now do MAC verification on ethernet segments. You can specify the set of allowed MAC addresses on the segment and you can optionally tie each MAC address to one or more IP addresses.
-- PPTP Servers and Clients running on the -firewall system may now be defined in the -/etc/shorewall/tunnels file.
-- A new 'ipsecnat' tunnel type is supported - for use when the remote IPSEC endpoint - is behind a NAT gateway.
-- The PATH used by Shorewall may now be specified - in /etc/shorewall/shorewall.conf.
-- The main firewall script is now /usr/lib/shorewall/firewall. - The script in /etc/init.d/shorewall is very small and uses /sbin/shorewall - to do the real work. This change makes custom distributions such - as for Debian and for Gentoo easier to manage since it is /etc/init.d/shorewall - that tends to have distribution-dependent code
- +- PPTP Servers and Clients running on + the firewall system may now be defined in the /etc/shorewall/tunnels file.
+- A new 'ipsecnat' tunnel type is supported + for use when the remote IPSEC endpoint + is behind a NAT gateway.
+- The PATH used by Shorewall may now +be specified in /etc/shorewall/shorewall.conf.
+- The main firewall script is now /usr/lib/shorewall/firewall. + The script in /etc/init.d/shorewall is very small and uses + /sbin/shorewall to do the real work. This change makes custom + distributions such as for Debian and for Gentoo easier to manage + since it is /etc/init.d/shorewall that tends to have distribution-dependent + code
+10/24/2002 - Shorewall is now in Gentoo Linux
- Alexandru Hartmann reports that his Shorewall - package is now a part of the -Gentoo Linux distribution. Thanks Alex!
-
- -10/23/2002 - Shorewall 1.3.10 Beta 1
- In this version:
+ + Alexandru Hartmann reports that his Shorewall + package is now a part of the + Gentoo Linux distribution. Thanks Alex!
- + +10/23/2002 - Shorewall 1.3.10 Beta 1
+ In this version:
+ +-
- You may download the Beta from:- You may now You may now define the contents of a zone dynamically -with the "shorewall add" and -"shorewall delete" commands. These commands are expected -to be used primarily within "shorewall add" +and "shorewall delete" commands. These commands are expected + to be used primarily within FreeS/Wan updown scripts.
-- Shorewall can now doShorewall can now do MAC verification on ethernet segments. - You can specify the set of allowed MAC addresses on the segment - and you can optionally tie each MAC address to one or more IP addresses.
-- PPTP Servers and Clients running on the -firewall system may now be defined in the -/etc/shorewall/tunnels file.
-- A new 'ipsecnat' tunnel type is supported - for use when the remote IPSEC endpoint - is behind a NAT gateway.
-- The PATH used by Shorewall may now be specified - in /etc/shorewall/shorewall.conf.
-- The main firewall script is now /usr/lib/shorewall/firewall. - The script in /etc/init.d/shorewall is very small and uses -/sbin/shorewall to do the real work. This change makes custom -distributions such as for Debian and for Gentoo easier to manage -since it is /etc/init.d/shorewall that tends to have distribution-dependent -code.
- + You can specify the set of allowed MAC addresses on the segment + and you can optionally tie each MAC address to one or more IP + addresses. +- PPTP Servers and Clients running +on the firewall system may now be defined in the /etc/shorewall/tunnels file.
+- A new 'ipsecnat' tunnel type is supported + for use when the remote IPSEC endpoint + is behind a NAT gateway.
+- The PATH used by Shorewall may now + be specified in /etc/shorewall/shorewall.conf.
+- The main firewall script is now /usr/lib/shorewall/firewall. + The script in /etc/init.d/shorewall is very small and uses + /sbin/shorewall to do the real work. This change makes custom + distributions such as for Debian and for Gentoo easier to manage + since it is /etc/init.d/shorewall that tends to have distribution-dependent + code.
+
- - - -10/10/2002 - Debian 1.3.9b Packages Available
+ You may download the Beta from:
-
- + + + +10/10/2002 - Debian 1.3.9b Packages Available
+ +
+Apt-get sources listed at http://security.dsi.unimi.it/~lorenzo/debian.html.
- +10/9/2002 - Shorewall 1.3.9b
- This release rolls up fixes to the installer - and to the firewall script.
- + This release rolls up fixes to the installer + and to the firewall script.
+10/6/2002 - Shorewall.net now running on RH8.0
- Roles up the fix for broken tunnels.
-
- The firewall and server here at shorewall.net - are now running RedHat release 8.0.
-
- 9/30/2002 - Shorewall 1.3.9a
- +
+ The firewall and server here at shorewall.net + are now running RedHat release 8.0.
+
+ 9/30/2002 - Shorewall 1.3.9a + Roles up the fix for broken tunnels.
+ +9/30/2002 - TUNNELS Broken in 1.3.9!!!
- There is an updated firewall script at ftp://www.shorewall.net/pub/shorewall/errata/1.3.9/firewall - -- copy that file to /usr/lib/shorewall/firewall.
- + -- copy that file to /usr/lib/shorewall/firewall.
+ +9/28/2002 - Shorewall 1.3.9
- + +In this version:
- + + +
--
- + +- DNS Names are now allowed in Shorewall config files (although I recommend against using them).
-- The connection SOURCE may now -be qualified by both interface and IP address in a Shorewall rule.
-- Shorewall startup is now disabled - after initial installation until the file /etc/shorewall/startup_disabled - is removed. This avoids nasty surprises during reboot for -users who install Shorewall but don't configure it.
-- The 'functions' and 'version' files - and the 'firewall' symbolic link have been moved from /var/lib/shorewall - to /usr/lib/shorewall to appease the LFS police at Debian.
- +
-- The connection SOURCE may + now be qualified by both interface and IP address in +a Shorewall rule.
+- Shorewall startup is now +disabled after initial installation until the file /etc/shorewall/startup_disabled + is removed. This avoids nasty surprises during reboot for + users who install Shorewall but don't configure it.
+- The 'functions' and 'version' + files and the 'firewall' symbolic link have been moved +from /var/lib/shorewall to /usr/lib/shorewall to appease +the LFS police at Debian.
+ +
+9/23/2002 - Full Shorewall Site/Mailing List Archive Search Capability - Restored
-
-
+ +- A couple of recent configuration -changes at www.shorewall.net broke the Search facility:
+ A couple of recent configuration + changes at www.shorewall.net broke the Search facility:
- +- + +- Hopefully these problems are now -corrected. + + Hopefully these problems are + now corrected.-
-- Mailing List Archive Search -was not available.
-- The Site Search index was incomplete
-- Only one page of matches was -presented.
+- Mailing List Archive Search + was not available.
+- The Site Search index +was incomplete
+- Only one page of matches + was presented.
- +9/23/2002 - Full Shorewall Site/Mailing List Archive Search Capability - Restored
- A couple of recent configuration changes - at www.shorewall.net had the negative effect of breaking - the Search facility:
-
+ Restored
+ + A couple of recent configuration + changes at www.shorewall.net had the negative effect +of breaking the Search facility:
- +-
- Hopefully these problems are now corrected.- Mailing List Archive Search was - not available.
-- The Site Search index was incomplete
-- Only one page of matches was -presented.
+- Mailing List Archive Search + was not available.
+- The Site Search index was + incomplete
+- Only one page of matches + was presented.
- +
+ Hopefully these problems are +now corrected.
- +9/18/2002 - Debian 1.3.8 Packages Available
+ - +
-Apt-get sources listed at http://security.dsi.unimi.it/~lorenzo/debian.html.
- +9/16/2002 - Shorewall 1.3.8
- +In this version:
- - -
--
+- A NEWNOTSYN option has been - added to shorewall.conf. This option determines whether Shorewall - accepts TCP packets which are not part of an established - connection and that are not 'SYN' packets (SYN flag on and ACK -flag off).
-- The need for the 'multi' option - to communicate between zones za and zb on the same interface - is removed in the case where the chain 'za2zb' and/or 'zb2za' - exists. 'za2zb' will exist if:
- - - --
- - -- There is a policy -for za to zb; or
-- There is at least one -rule for za to zb.
- - - --
- + +- The /etc/shorewall/blacklist - file now contains three columns. In addition to the SUBNET/ADDRESS - column, there are optional PROTOCOL and PORT columns to -block only certain applications from the blacklisted addresses.
+
-- A NEWNOTSYN option has been + added to shorewall.conf. This option determines whether Shorewall + accepts TCP packets which are not part of an established + connection and that are not 'SYN' packets (SYN flag on and +ACK flag off).
+- The need for the 'multi' + option to communicate between zones za and zb on the +same interface is removed in the case where the chain 'za2zb' + and/or 'zb2za' exists. 'za2zb' will exist if:
- + + ++
+ +- There is a +policy for za to zb; or
+- There is at least + one rule for za to zb.
+ + + ++
+ +- The /etc/shorewall/blacklist + file now contains three columns. In addition to the SUBNET/ADDRESS + column, there are optional PROTOCOL and PORT columns to + block only certain applications from the blacklisted addresses.
+ + +
+9/11/2002 - Debian 1.3.7c Packages Available
- +Apt-get sources listed at http://security.dsi.unimi.it/~lorenzo/debian.html.
- +9/2/2002 - Shorewall 1.3.7c
- +This is a role up of a fix for "DNAT" rules where the source zone is $FW - (fw).
+ (fw). - +8/31/2002 - I'm not available
- +I'm currently on vacation -- please respect my need for a couple of weeks free of Shorewall problem reports.
- +-Tom
- +8/26/2002 - Shorewall 1.3.7b
- +This is a role up of the "shorewall refresh" bug fix and the change which - reverses the order of "dhcp" and "norfc1918" checking.
+ reverses the order of "dhcp" and "norfc1918" checking. - +8/26/2002 - French FTP Mirror is Operational
- +ftp://france.shorewall.net/pub/mirrors/shorewall - is now available.
+ is now available. - +8/25/2002 - Shorewall Mirror in France
- +Thanks to a Shorewall user in Paris, the Shorewall web site is now mirrored - at http://france.shorewall.net.
- +8/25/2002 - Shorewall 1.3.7a Debian Packages Available
- +Lorenzo Martignoni reports that the packages for version 1.3.7a are available - at http://security.dsi.unimi.it/~lorenzo/debian.html.
- +8/22/2002 - Shorewall 1.3.7 Wins a Brown Paper Bag Award for its Author - -- Shorewall 1.3.7a released
+ - +-
1.3.7a corrects problems occurring in rules file processing when starting - Shorewall 1.3.7.
+ Shorewall 1.3.7. - +8/22/2002 - Shorewall 1.3.7 Released 8/13/2002
- +Features in this release include:
- +-
- +- The 'icmp.def' file is now - empty! The rules in that file were required in ipchains - firewalls but are not required in Shorewall. Users who have - ALLOWRELATED=No in shorewall.conf - should see the Upgrade Issues.
-- A 'FORWARDPING' option has - been added to shorewall.conf. - The effect of setting this variable to Yes is the same - as the effect of adding an ACCEPT rule for ICMP echo-request - in /etc/shorewall/icmpdef. - Users who have such a rule in icmpdef are encouraged - to switch to FORWARDPING=Yes.
-- The loopback CLASS A Network - (127.0.0.0/8) has been added to the rfc1918 file.
-- Shorewall now works with -iptables 1.2.7
-- The documentation and web - site no longer uses FrontPage themes.
+- The 'icmp.def' file + is now empty! The rules in that file were required in + ipchains firewalls but are not required in Shorewall. + Users who have ALLOWRELATED=No in shorewall.conf should see the + Upgrade Issues.
+- A 'FORWARDPING' option + has been added to shorewall.conf. + The effect of setting this variable to Yes is the +same as the effect of adding an ACCEPT rule for ICMP +echo-request in /etc/shorewall/icmpdef. + Users who have such a rule in icmpdef are encouraged + to switch to FORWARDPING=Yes.
+- The loopback CLASS +A Network (127.0.0.0/8) has been added to the rfc1918 + file.
+- Shorewall now works + with iptables 1.2.7
+- The documentation +and web site no longer uses FrontPage themes.
- +I would like to thank John Distler for his valuable input regarding TCP - SYN and ICMP treatment in Shorewall. That input has -led to marked improvement in Shorewall in the last two releases.
+ SYN and ICMP treatment in Shorewall. That input has + led to marked improvement in Shorewall in the last two + releases. - +8/13/2002 - Documentation in the CVS Repository
- +The Shorewall-docs project now contains just the HTML and image files - the Frontpage files have been removed.
- +8/7/2002 - STABLE branch added to CVS Repository
- +This branch will only be updated after I release a new version of Shorewall - so you can always update from this branch to get the - latest stable tree.
+ so you can always update from this branch to get +the latest stable tree. - +8/7/2002 - Upgrade Issues section added to the Errata Page
- +Now there is one place to go to look for issues involved with upgrading - to recent versions of Shorewall.
+ to recent versions of Shorewall. - +8/7/2002 - Shorewall 1.3.6
- +This is primarily a bug-fix rollup with a couple of new features:
- +-
- +- The latest The latest QuickStart Guides including the Shorewall Setup Guide.
-- Shorewall will now DROP -TCP packets that are not part of or related to an existing - connection and that are not SYN packets. These "New not - SYN" packets may be optionally logged by setting the LOGNEWNOTSYN - option in /etc/shorewall/shorewall.conf.
-- The processing of "New not - SYN" packets may be extended by commands in the new - newnotsyn extension script.
+- Shorewall will now +DROP TCP packets that are not part of or related to +an existing connection and that are not SYN packets. These + "New not SYN" packets may be optionally logged by setting + the LOGNEWNOTSYN option in /etc/shorewall/shorewall.conf.
+- The processing of +"New not SYN" packets may be extended by commands in + the new newnotsyn +extension script.
- +7/30/2002 - Shorewall 1.3.5b Released
- +This interim release:
- +-
- +- Causes the firewall script - to remove the lock file if it is killed.
-- Once again allows lists -in the second column of the Causes the firewall + script to remove the lock file if it is killed.
+- Once again allows +lists in the second column of the /etc/shorewall/hosts file.
-- Includes the latest QuickStart Guides.
+- Includes the latest + QuickStart Guides.
- +7/29/2002 - New Shorewall Setup Guide Available
- +The first draft of this guide is available at http://www.shorewall.net/shorewall_setup_guide.htm. - The guide is intended for use by people who are setting - up Shorewall to manage multiple public IP addresses and - by people who want to learn more about Shorewall than is described - in the single-address guides. Feedback on the new guide is -welcome.
+ The guide is intended for use by people who are setting + up Shorewall to manage multiple public IP addresses +and by people who want to learn more about Shorewall than +is described in the single-address guides. Feedback on the +new guide is welcome. - +7/28/2002 - Shorewall 1.3.5 Debian Package Available
- +Lorenzo Martignoni reports that the packages are version 1.3.5a and are - available at http://security.dsi.unimi.it/~lorenzo/debian.html.
- +7/27/2002 - Shorewall 1.3.5a Released
- +This interim release restores correct handling of REDIRECT rules.
- +7/26/2002 - Shorewall 1.3.5 Released
- +This will be the last Shorewall release for a while. I'm going to be focusing on rewriting a lot of the documentation.
- +In this version:
- +-
- +- Empty and invalid source -and destination qualifiers are now detected in the -rules file. It is a good idea to use the 'shorewall check' command - before you issue a 'shorewall restart' command be be sure - that you don't have any configuration problems that will prevent - a successful restart.
-- Added MERGE_HOSTS -variable in shorewall.conf -to provide saner behavior of the /etc/shorewall/hosts - file.
-- The time that the counters - were last reset is now displayed in the heading of the - 'status' and 'show' commands.
-- A proxyarp option -has been added for entries in Empty and invalid +source and destination qualifiers are now detected +in the rules file. It is a good idea to use the 'shorewall + check' command before you issue a 'shorewall restart' + command be be sure that you don't have any configuration problems + that will prevent a successful restart.
+- Added MERGE_HOSTS + variable in shorewall.conf + to provide saner behavior of the /etc/shorewall/hosts + file.
+- The time that the +counters were last reset is now displayed in the + heading of the 'status' and 'show' commands.
+- A proxyarp option + has been added for entries in /etc/shorewall/interfaces. This option facilitates Proxy ARP sub-netting as described in the Proxy ARP subnetting mini-HOWTO (http://www.tldp.org/HOWTO/mini/Proxy-ARP-Subnet/). - Specifying the proxyarp option for an interface causes - Shorewall to set /proc/sys/net/ipv4/conf/<interface>/proxy_arp.
-- The Samples have been updated - to reflect the new capabilities in this release.
+ Specifying the proxyarp option for an interface + causes Shorewall to set /proc/sys/net/ipv4/conf/<interface>/proxy_arp. +- The Samples have been + updated to reflect the new capabilities in this + release.
- +7/16/2002 - New Mirror in Argentina
- +Thanks to Arturo "Buanzo" Busleiman, there is now a Shorewall mirror in - Argentina. Thanks Buanzo!!!
+ Argentina. Thanks Buanzo!!! - +7/16/2002 - Shorewall 1.3.4 Released
- +In this version:
- +-
- +- A new A new /etc/shorewall/routestopped - file has been added. This file is intended to eventually - replace the routestopped option in the /etc/shorewall/interface - and /etc/shorewall/hosts files. This new file makes -remote firewall administration easier by allowing any IP or -subnet to be enabled while Shorewall is stopped.
-- An /etc/shorewall/stopped - extension script has been - added. This script is invoked after Shorewall has - stopped.
-- A DETECT_DNAT_ADDRS option - has been added to /etc/shoreall/shorewall.conf. - When this option is selected, DNAT rules only apply - when the destination address is the external interface's + file has been added. This file is intended to eventually + replace the routestopped option in the + /etc/shorewall/interface and /etc/shorewall/hosts files. + This new file makes remote firewall administration easier +by allowing any IP or subnet to be enabled while Shorewall +is stopped.
+- An /etc/shorewall/stopped + extension script has + been added. This script is invoked after Shorewall has + stopped.
+- A DETECT_DNAT_ADDRS + option has been added to /etc/shoreall/shorewall.conf. + When this option is selected, DNAT rules only apply when + the destination address is the external interface's primary IP address.
-- The The QuickStart Guide has - been broken into three guides and has been almost entirely - rewritten.
-- The Samples have been updated - to reflect the new capabilities in this release.
+ been broken into three guides and has been almost entirely + rewritten. +- The Samples have been + updated to reflect the new capabilities in this + release.
- +7/8/2002 - Shorewall 1.3.3 Debian Package Available
- +Lorenzo Marignoni reports that the packages are available at http://security.dsi.unimi.it/~lorenzo/debian.html.
- +7/6/2002 - Shorewall 1.3.3 Released
- +In this version:
- +-
- +- Entries in /etc/shorewall/interface - that use the wildcard character ("+") now have the -"multi" option assumed.
-- The 'rfc1918' chain in the - mangle table has been renamed 'man1918' to make log - messages generated from that chain distinguishable from those - generated by the 'rfc1918' chain in the filter table.
-- Interface names appearing - in the hosts file are now validated against the interfaces - file.
-- The TARGET column in the -rfc1918 file is now checked for correctness.
-- The chain structure in the - nat table has been changed to reduce the number of rules - that a packet must traverse and to correct problems with - NAT_BEFORE_RULES=No
-- The "hits" command has been - enhanced.
+- Entries in /etc/shorewall/interface + that use the wildcard character ("+") now have +the "multi" option assumed.
+- The 'rfc1918' chain + in the mangle table has been renamed 'man1918' to + make log messages generated from that chain distinguishable + from those generated by the 'rfc1918' chain in the +filter table.
+- Interface names appearing + in the hosts file are now validated against the + interfaces file.
+- The TARGET column +in the rfc1918 file is now checked for correctness.
+- The chain structure + in the nat table has been changed to reduce the +number of rules that a packet must traverse and to correct +problems with NAT_BEFORE_RULES=No
+- The "hits" command +has been enhanced.
- +6/25/2002 - Samples Updated for 1.3.2
- +The comments in the sample configuration files have been updated to reflect - new features introduced in Shorewall 1.3.2.
+ new features introduced in Shorewall 1.3.2. - +6/25/2002 - Shorewall 1.3.1 Debian Package Available
- +Lorenzo Marignoni reports that the package is available at http://security.dsi.unimi.it/~lorenzo/debian.html.
- +6/19/2002 - Documentation Available in PDF Format
- +Thanks to Mike Martinez, the Shorewall Documentation is now available for download in Adobe PDF format.
- +6/16/2002 - Shorewall 1.3.2 Released
- +In this version:
- +-
- +- A A logwatch command has been added to /sbin/shorewall.
-- A A dynamic blacklist facility has been added.
-- Support for the Support for the Netfilter multiport match function - has been added.
-- The files firewall, functions - and version have been moved from - /etc/shorewall to /var/lib/shorewall.
+ has been added. +- The files firewall, + functions and version have been moved + from /etc/shorewall to /var/lib/shorewall.
- +6/6/2002 - Why CVS Web access is Password Protected
- +Last weekend, I installed the CVS Web package to provide brower-based access to the Shorewall CVS repository. Since then, I have had several instances where my server was almost unusable due to the high load generated by website copying tools like HTTrack and WebStripper. These mindless tools:
- +-
- +- Ignore robot.txt files.
-- Recursively copy everything - that they find.
-- Should be classified as -weapons rather than tools.
+- Ignore robot.txt files.
+- Recursively copy everything + that they find.
+- Should be classified + as weapons rather than tools.
- +These tools/weapons are particularly damaging when combined with CVS Web - because they doggedly follow every link in the cgi-generated - HTML resulting in 1000s of executions of the cvsweb.cgi - script. Yesterday, I spend several hours implementing measures - to block these tools but unfortunately, these measures resulted - in my server OOM-ing under even moderate load.
+ because they doggedly follow every link in the cgi-generated + HTML resulting in 1000s of executions of the cvsweb.cgi + script. Yesterday, I spend several hours implementing + measures to block these tools but unfortunately, these measures + resulted in my server OOM-ing under even moderate load. - +Until I have the time to understand the cause of the OOM (or until I buy - more RAM if that is what is required), CVS Web access - will remain Password Protected.
+ more RAM if that is what is required), CVS Web access + will remain Password Protected. - +6/5/2002 - Shorewall 1.3.1 Debian Package Available
- +Lorenzo Marignoni reports that the package is available at http://security.dsi.unimi.it/~lorenzo/debian.html.
- +6/2/2002 - Samples Corrected
- +The 1.3.0 samples configurations had several serious problems that prevented - DNS and SSH from working properly. These problems have - been corrected in the 1.3.1 samples.
- +6/1/2002 - Shorewall 1.3.1 Released
- +Hot on the heels of 1.3.0, this release:
- +-
- +- Corrects a serious problem - with "all <zone> CONTINUE" policies. - This problem is present in all versions of Shorewall that - support the CONTINUE policy. These previous versions optimized - away the "all2<zone>" chain and replaced it with - the "all2all" chain with the usual result that a policy of REJECT - was enforced rather than the intended CONTINUE policy.
-- Adds an Corrects a serious +problem with "all <zone> CONTINUE" +policies. This problem is present in all versions of Shorewall + that support the CONTINUE policy. These previous versions + optimized away the "all2<zone>" chain and +replaced it with the "all2all" chain with the usual result that a + policy of REJECT was enforced rather than the intended CONTINUE policy.
+- Adds an /etc/shorewall/rfc1918 file for defining the exact behavior of the 'norfc1918' interface option.
- +5/29/2002 - Shorewall 1.3.0 Released
- +In addition to the changes in Beta 1, Beta 2 and RC1, Shorewall 1.3.0 includes:
- +-
- +- A 'filterping' interface -option that allows ICMP echo-request (ping) requests -addressed to the firewall to be handled by entries in /etc/shorewall/rules - and /etc/shorewall/policy.
+- A 'filterping' interface + option that allows ICMP echo-request (ping) requests + addressed to the firewall to be handled by entries in +/etc/shorewall/rules and /etc/shorewall/policy.
- +5/23/2002 - Shorewall 1.3 RC1 Available
- +In addition to the changes in Beta 1 and Beta 2, RC1 (Version 1.2.92) incorporates the following:
- +-
- +- Support for the /etc/shorewall/whitelist - file has been withdrawn. If you need whitelisting, -see these instructions.
+- Support for the /etc/shorewall/whitelist + file has been withdrawn. If you need whitelisting, + see these instructions.
- +5/19/2002 - Shorewall 1.3 Beta 2 Available
- +In addition to the changes in Beta 1, this release which carries the designation 1.2.91 adds:
- +-
- +- The structure of the firewall - is changed markedly. There is now an INPUT and a FORWARD - chain for each interface; this reduces the number of rules - that a packet must traverse, especially in complicated setups.
-- The structure of the + firewall is changed markedly. There is now an INPUT + and a FORWARD chain for each interface; this reduces the + number of rules that a packet must traverse, especially in + complicated setups.
+- Sub-zones may now be excluded - from DNAT and REDIRECT rules.
-- The names of the columns -in a number of the configuration files have been changed - to be more consistent and self-explanatory and the documentation - has been updated accordingly.
-- The sample configurations - have been updated for 1.3.
+ from DNAT and REDIRECT rules. +- The names of the columns + in a number of the configuration files have been +changed to be more consistent and self-explanatory and the + documentation has been updated accordingly.
+- The sample configurations + have been updated for 1.3.
- +5/17/2002 - Shorewall 1.3 Beta 1 Available
- +Beta 1 carries the version designation 1.2.90 and implements the following - features:
+ features: - +-
- +- Simplified rule syntax which - makes the intent of each rule clearer and hopefully -makes Shorewall easier to learn.
-- Upward compatibility with - 1.2 configuration files has been maintained so that - current users can migrate to the new syntax at their convenience.
-- Simplified rule syntax + which makes the intent of each rule clearer and hopefully + makes Shorewall easier to learn.
+- Upward compatibility + with 1.2 configuration files has been maintained so + that current users can migrate to the new syntax at their + convenience.
+- WARNING: Compatibility with the old parameterized sample configurations has NOT been maintained. Users still running those configurations should migrate - to the new sample configurations before upgrading to 1.3 -Beta 1.
+ to the new sample configurations before upgrading to +1.3 Beta 1. - +5/4/2002 - Shorewall 1.2.13 is Available
- +In this version:
- +-
- +- White-listing is supported.
-- SYN-flood protection is - added.
-- IP addresses added under - ADD_IP_ALIASES and ADD_SNAT_ALIASES - now inherit the VLSM and Broadcast Address of the interface's - primary IP address.
-- The order in which port -forwarding DNAT and Static DNAT +
- IP addresses added +under ADD_IP_ALIASES and ADD_SNAT_ALIASES + now inherit the VLSM and Broadcast Address of the + interface's primary IP address.
+- The order in which +port forwarding DNAT and Static DNAT can now be reversed so that port forwarding rules can override the contents of /etc/shorewall/nat.
- +4/30/2002 - Shorewall Debian News
- +Lorenzo Marignoni reports that Shorewall 1.2.12 is now in both the Debian Testing Branch and the Debian Unstable Branch.
- +4/20/2002 - Shorewall 1.2.12 is Available
- +-
- +- The 'try' command works -again
-- There is now a single RPM - that also works with SuSE.
+- The 'try' command +works again
+- There is now a single + RPM that also works with SuSE.
- +4/17/2002 - Shorewall Debian News
- +Lorenzo Marignoni reports that:
- +-
- +- Shorewall 1.2.10 is in the - Debian - Testing Branch
-- Shorewall 1.2.11 is in the - Debian - Unstable Branch
+- Shorewall 1.2.10 is + in the Debian + Testing Branch
+- Shorewall 1.2.11 is + in the Debian + Unstable Branch
- +Thanks, Lorenzo!
- +4/16/2002 - Shorewall 1.2.11 RPM Available for SuSE
- +Thanks to Stefan Mohr, there - is now a Shorewall 1.2.11 - SuSE RPM available.
+ SuSE RPM available. - +4/13/2002 - Shorewall 1.2.11 Available
- +In this version:
- +-
- +- The 'try' command now accepts - an optional timeout. If the timeout is given in the -command, the standard configuration will automatically be - restarted after the new configuration has been running for -that length of time. This prevents a remote admin from being -locked out of the firewall in the case where the new configuration - starts but prevents access.
-- Kernel route filtering may - now be enabled globally using the new ROUTE_FILTER -parameter in /etc/shorewall/shorewall.conf.
-- Individual IP source addresses - and/or subnets may now be excluded from masquerading/SNAT.
-- Simple "Yes/No" and "On/Off" - values are now case-insensitive in /etc/shorewall/shorewall.conf.
+- The 'try' command +now accepts an optional timeout. If the timeout is + given in the command, the standard configuration will automatically + be restarted after the new configuration has been running + for that length of time. This prevents a remote admin from + being locked out of the firewall in the case where the new configuration + starts but prevents access.
+- Kernel route filtering + may now be enabled globally using the new ROUTE_FILTER + parameter in /etc/shorewall/shorewall.conf.
+- Individual IP source + addresses and/or subnets may now be excluded from + masquerading/SNAT.
+- Simple "Yes/No" and + "On/Off" values are now case-insensitive in /etc/shorewall/shorewall.conf.
- +4/13/2002 - Hamburg Mirror now has FTP
- +Stefan now has an FTP mirror at ftp://germany.shorewall.net/pub/shorewall. - Thanks Stefan!
+ Thanks Stefan! - +4/12/2002 - New Mirror in Hamburg
- +Thanks to Stefan Mohr, there - is now a mirror of the Shorewall website at http://germany.shorewall.net. -
+ - +4/10/2002 - Shorewall QuickStart Guide Version 1.1 Available
- +Version 1.1 of the QuickStart - Guide is now available. Thanks to those who have - read version 1.0 and offered their suggestions. Corrections - have also been made to the sample scripts.
+ Guide is now available. Thanks to those who have + read version 1.0 and offered their suggestions. Corrections + have also been made to the sample scripts. - +4/9/2002 - Shorewall QuickStart Guide Version 1.0 Available
- +Version 1.0 of the QuickStart - Guide is now available. This Guide and its accompanying - sample configurations are expected to provide a replacement - for the recently withdrawn parameterized samples.
+ Guide is now available. This Guide and its accompanying + sample configurations are expected to provide a replacement + for the recently withdrawn parameterized samples. - +4/8/2002 - Parameterized Samples Withdrawn
- +Although the parameterized - samples have allowed people to get a firewall up - and running quickly, they have unfortunately set the wrong - level of expectation among those who have used them. I am - therefore withdrawing support for the samples and I am recommending - that they not be used in new Shorewall installations.
+ samples have allowed people to get a firewall + up and running quickly, they have unfortunately set the + wrong level of expectation among those who have used +them. I am therefore withdrawing support for the samples +and I am recommending that they not be used in new Shorewall installations. - +4/2/2002 - Updated Log Parser
- +John Lodge has provided an updated - version of his CGI-based - log parser with corrected date handling.
+ version of his CGI-based log parser + with corrected date handling. - +3/30/2002 - Shorewall Website Search Improvements
- +The quick search on the home page now excludes the mailing list archives. - The Extended Search -allows excluding the archives or restricting the search -to just the archives. An archive search form is also available -on the mailing - list information page.
+ The Extended Search + allows excluding the archives or restricting the search + to just the archives. An archive search form is also available + on the mailing + list information page. - +3/28/2002 - Debian Shorewall News (From Lorenzo Martignoni)
- +-
- +- The 1.2.10 Debian Package - is available at The 1.2.10 Debian +Package is available at http://security.dsi.unimi.it/~lorenzo/debian.html.
-- Shorewall 1.2.9 is now in - the Shorewall 1.2.9 is +now in the Debian Unstable Distribution.
- +3/25/2002 - Log Parser Available
- +John Lodge has provided a CGI-based log parser for Shorewall. Thanks - John.
+ John. - +3/20/2002 - Shorewall 1.2.10 Released
- +In this version:
- +-
- +- A "shorewall try" command - has been added (syntax: shorewall try <configuration - directory>). This command attempts "shorewall -c - <configuration directory> start" and if that results - in the firewall being stopped due to an error, a "shorewall -start" command is executed. The 'try' command allows you to -create a new configuration - and attempt to start it; if there is an error that leaves your - firewall in the stopped state, it will automatically be restarted - using the default configuration (in /etc/shorewall).
-- A new variable ADD_SNAT_ALIASES - has been added to /etc/shorewall/shorewall.conf. - If this variable is set to "Yes", Shorewall will -automatically add IP addresses listed in the third -column of the /etc/shorewall/masq -file.
-- Copyright notices have been - added to the documenation.
+- A "shorewall try" +command has been added (syntax: shorewall try + <configuration directory>). This command attempts + "shorewall -c <configuration directory> + start" and if that results in the firewall being stopped due + to an error, a "shorewall start" command is executed. The + 'try' command allows you to create a new configuration and attempt + to start it; if there is an error that leaves your firewall + in the stopped state, it will automatically be restarted using + the default configuration (in /etc/shorewall).
+- A new variable ADD_SNAT_ALIASES + has been added to /etc/shorewall/shorewall.conf. + If this variable is set to "Yes", Shorewall will + automatically add IP addresses listed in the third + column of the /etc/shorewall/masq + file.
+- Copyright notices +have been added to the documenation.
- +3/11/2002 - Shorewall 1.2.9 Released
- +In this version:
- +-
- +- Filtering by Filtering by MAC address has been added. MAC addresses may be used as the source address in: - + +
--
-- Filtering rules (/etc/shorewall/rules)
-- Traffic Control Classification - Rules (/etc/shorewall/tcrules)
-- TOS Rules (Filtering rules +(/etc/shorewall/rules)
+- Traffic Control +Classification Rules (/etc/shorewall/tcrules)
+- TOS Rules (/etc/shorewall/tos)
-- Blacklist (Blacklist (/etc/shorewall/blacklist)
- +- Several bugs have been fixed
-- The 1.2.9 Debian Package -is also available at +
- Several bugs have +been fixed
+- The 1.2.9 Debian Package + is also available at http://security.dsi.unimi.it/~lorenzo/debian.html.
- +3/1/2002 - 1.2.8 Debian Package is Available
- +See http://security.dsi.unimi.it/~lorenzo/debian.html
- +2/25/2002 - New Two-interface Sample
- +I've enhanced the two interface sample to allow access from the firewall - to servers in the local zone - - http://www.shorewall.net/pub/shorewall/LATEST.samples/two-interfaces.tgz
+ http://www.shorewall.net/pub/shorewall/LATEST.samples/two-interfaces.tgz - +2/23/2002 - Shorewall 1.2.8 Released
- +Do to a serious problem with 1.2.7, I am releasing 1.2.8. It corrects problems associated with the lock file used to prevent multiple state-changing - operations from occuring simultaneously. My apologies - for any inconvenience my carelessness may have caused.
+ operations from occuring simultaneously. My apologies + for any inconvenience my carelessness may have caused. - +2/22/2002 - Shorewall 1.2.7 Released
- +In this version:
- +-
- +- UPnP probes (UDP destination - port 1900) are now silently dropped in the common - chain
-- RFC 1918 checking in the -mangle table has been streamlined to no longer require -packet marking. RFC 1918 checking in the filter table has -been changed to require half as many rules as previously.
-- A 'shorewall check' command - has been added that does a cursory validation of the - zones, interfaces, hosts, rules and policy files.
+- UPnP probes (UDP destination + port 1900) are now silently dropped in the common + chain
+- RFC 1918 checking +in the mangle table has been streamlined to no longer + require packet marking. RFC 1918 checking in the filter + table has been changed to require half as many rules as previously.
+- A 'shorewall check' + command has been added that does a cursory validation + of the zones, interfaces, hosts, rules and policy files.
- +2/18/2002 - 1.2.6 Debian Package is Available
- +See http://security.dsi.unimi.it/~lorenzo/debian.html
- +2/8/2002 - Shorewall 1.2.6 Released
- +In this version:
- +-
- +- $-variables may now be used - anywhere in the configuration files except /etc/shorewall/zones.
-- The interfaces and hosts -files now have their contents validated before any -changes are made to the existing Netfilter configuration. The -appearance of a zone name that isn't defined in /etc/shorewall/zones - causes "shorewall start" and "shorewall restart" to abort without - changing the Shorewall state. Unknown options in either file -cause a warning to be issued.
-- A problem occurring when -BLACKLIST_LOGLEVEL was not set has been corrected.
+- $-variables may now + be used anywhere in the configuration files except + /etc/shorewall/zones.
+- The interfaces and +hosts files now have their contents validated before + any changes are made to the existing Netfilter configuration. + The appearance of a zone name that isn't defined in /etc/shorewall/zones + causes "shorewall start" and "shorewall restart" to abort + without changing the Shorewall state. Unknown options in either + file cause a warning to be issued.
+- A problem occurring + when BLACKLIST_LOGLEVEL was not set has been corrected.
- +2/4/2002 - Shorewall 1.2.5 Debian Package Available
- +see http://security.dsi.unimi.it/~lorenzo/debian.html
- +2/1/2002 - Shorewall 1.2.5 Released
- +Due to installation problems with Shorewall 1.2.4, I have released Shorewall - 1.2.5. Sorry for the rapid-fire development.
+ 1.2.5. Sorry for the rapid-fire development. - +In version 1.2.5:
- +-
- +- The installation problems -have been corrected.
-- The installation problems + have been corrected.
+- SNAT is now supported.
-- A "shorewall version" command - has been added
-- The default value of the -STATEDIR variable in /etc/shorewall/shorewall.conf has -been changed to /var/lib/shorewall in order to conform to -the GNU/Linux File Hierarchy Standard, Version 2.2.
+- A "shorewall version" + command has been added
+- The default value of + the STATEDIR variable in /etc/shorewall/shorewall.conf + has been changed to /var/lib/shorewall in order to +conform to the GNU/Linux File Hierarchy Standard, Version + 2.2.
- +1/28/2002 - Shorewall 1.2.4 Released
- +-
- +- The "fw" zone The "fw" zone may now be given a different name.
-- You may now place end-of-line - comments (preceded by '#') in any of the configuration - files
-- There is now protection against - against two state changing operations occuring concurrently. - This is implemented using the 'lockfile' utility if it - is available (lockfile is part of procmail); otherwise, a less - robust technique is used. The lockfile is created in the STATEDIR - defined in /etc/shorewall/shorewall.conf and has the name -"lock".
-- "shorewall start" no longer - fails if "detect" is specified in You may now place end-of-line + comments (preceded by '#') in any of the configuration + files
+- There is now protection + against against two state changing operations occuring + concurrently. This is implemented using the 'lockfile' utility + if it is available (lockfile is part of procmail); otherwise, + a less robust technique is used. The lockfile is created + in the STATEDIR defined in /etc/shorewall/shorewall.conf + and has the name "lock".
+- "shorewall start" no + longer fails if "detect" is specified in /etc/shorewall/interfaces for an interface with subnet mask 255.255.255.255.
- +1/27/2002 - Shorewall 1.2.3 Debian Package Available -- see http://security.dsi.unimi.it/~lorenzo/debian.html
- +1/20/2002 - Corrected firewall script available
- +Corrects a problem with BLACKLIST_LOGLEVEL. See the - errata for details.
+ errata for details. - +1/19/2002 - Shorewall 1.2.3 Released
- +This is a minor feature and bugfix release. The single new feature is:
- +-
- +- Support for TCP MSS Clamp -to PMTU -- This support is usually required when the -internet connection is via PPPoE or PPTP and may be enabled -using the CLAMPMSS option -in /etc/shorewall/shorewall.conf.
+- Support for TCP MSS +Clamp to PMTU -- This support is usually required when + the internet connection is via PPPoE or PPTP and may be +enabled using the CLAMPMSS + option in /etc/shorewall/shorewall.conf.
- +The following problems were corrected:
- +-
- +- The "shorewall status" command - no longer hangs.
-- The "shorewall monitor" command - now displays the icmpdef chain
-- The CLIENT PORT(S) column -in tcrules is no longer ignored
+- The "shorewall status" + command no longer hangs.
+- The "shorewall monitor" + command now displays the icmpdef chain
+- The CLIENT PORT(S) +column in tcrules is no longer ignored
- +1/18/2002 - Shorewall 1.2.2 packaged with new LEAF release
- +Jacques Nilo and Eric Wolzak have released a kernel 2.4.16 LEAF distribution - that includes Shorewall 1.2.2. See http://leaf.sourceforge.net/devel/jnilo - for details.
+ for details. - +1/11/2002 - Debian Package (.deb) Now Available - Thanks to Lorenzo Martignoni, a 1.2.2 - Shorewall Debian package is now available. There is a -link to Lorenzo's site from the Shorewall - download page.
+ Shorewall Debian package is now available. There is + a link to Lorenzo's site from the Shorewall download page. - +1/9/2002 - Updated 1.2.2 /sbin/shorewall available - This corrected version restores - the "shorewall status" command to health.
+ the "shorewall status" command to health. - +1/8/2002 - Shorewall 1.2.2 Released
- +In version 1.2.2
- +-
- +- Support for IP blacklisting - has been added +
- Support for IP blacklisting + has been added - +
--
-- You specify whether you -want packets from blacklisted hosts dropped or -rejected using the You specify whether + you want packets from blacklisted hosts dropped or + rejected using the BLACKLIST_DISPOSITION setting in /etc/shorewall/shorewall.conf
-- You specify whether you -want packets from blacklisted hosts logged and -at what syslog level using the You specify whether + you want packets from blacklisted hosts logged and + at what syslog level using the BLACKLIST_LOGLEVEL setting in /etc/shorewall/shorewall.conf
-- You list the IP addresses/subnets - that you wish to blacklist in You list the IP addresses/subnets + that you wish to blacklist in /etc/shorewall/blacklist
-- You specify the interfaces - you want checked against the blacklist using -the new "blacklist" - option in /etc/shorewall/interfaces.
-- The black list is refreshed - from /etc/shorewall/blacklist by the "shorewall - refresh" command.
+- You specify the interfaces + you want checked against the blacklist using + the new "blacklist" + option in /etc/shorewall/interfaces.
+- The black list is +refreshed from /etc/shorewall/blacklist by the + "shorewall refresh" command.
- +- Use of TCP RST replies has - been expanded +
+- Use of TCP RST replies + has been expanded - +
--
-- TCP connection requests -rejected because of a REJECT policy are now replied -with a TCP RST packet.
-- TCP connection requests -rejected because of a protocol=all rule in /etc/shorewall/rules - are now replied with a TCP RST packet.
+- TCP connection requests + rejected because of a REJECT policy are now replied + with a TCP RST packet.
+- TCP connection requests + rejected because of a protocol=all rule in /etc/shorewall/rules + are now replied with a TCP RST packet.
- +- A +
- +- A LOGFILE specification has been added to /etc/shorewall/shorewall.conf. LOGFILE is used to tell the /sbin/shorewall program where to look for Shorewall - messages.
+ messages.1/5/2002 - New Parameterized Samples (version 1.2.0) released. These are minor updates - to the previously-released samples. There are two new -rules added:
+ to the previously-released samples. There are two new + rules added: - +-
- +- Unless you have explicitly - enabled Auth connections (tcp port 113) to your firewall, - these connections will be REJECTED rather than DROPPED. - This speeds up connection establishment to some servers.
-- Orphan DNS replies are now - silently dropped.
+- Unless you have explicitly + enabled Auth connections (tcp port 113) to your + firewall, these connections will be REJECTED rather than + DROPPED. This speeds up connection establishment to some +servers.
+- Orphan DNS replies +are now silently dropped.
- +See the README file for upgrade instructions.
- +1/1/2002 - Shorewall Mailing List Moving
- +The Shorewall mailing list hosted at - Sourceforge is moving to Shorewall.net. If you are - a current subscriber to the list at Sourceforge, please see these instructions. - If you would like to subscribe to the new list, visit -http://www.shorewall.net/mailman/listinfo/shorewall-users.
+ Sourceforge is moving to Shorewall.net. If you + are a current subscriber to the list at Sourceforge, please + see these instructions. + If you would like to subscribe to the new list, visit + http://www.shorewall.net/mailman/listinfo/shorewall-users. - +12/31/2001 - Shorewall 1.2.1 Released
- +In version 1.2.1:
- +-
- +- Logging of Mangled/Invalid - Packets is added.
-- The tunnel - script has been corrected.
-- 'shorewall show tc' now correctly - handles tunnels.
+ Packets is added. +- The tunnel script has been corrected.
+- 'shorewall show tc' +now correctly handles tunnels.
- +12/21/2001 - Shorewall 1.2.0 Released! - I couldn't resist releasing 1.2 on 12/21/2001
- +Version 1.2 contains the following new features:
- +-
- +- Support for Support for Traffic Control/Shaping
-- Support for Support for Filtering of Mangled/Invalid Packets
-- Support for Support for GRE Tunnels
- +For the next month or so, I will continue to provide corrections to version - 1.1.18 as necessary so that current version 1.1.x users - will not be forced into a quick upgrade to 1.2.0 just to -have access to bug fixes.
+ 1.1.18 as necessary so that current version 1.1.x + users will not be forced into a quick upgrade to 1.2.0 +just to have access to bug fixes. - +For those of you who have installed one of the Beta RPMS, you will need - to use the "--oldpackage" option when upgrading to 1.2.0:
+ to use the "--oldpackage" option when upgrading to + 1.2.0: - +- -- + +rpm -Uvh --oldpackage shorewall-1.2-0.noarch.rpm
-rpm -Uvh --oldpackage shorewall-1.2-0.noarch.rpm
+ + +12/19/2001 - Thanks to Steve - Cowles, there is now a Shorewall mirror in Texas. - This web site is mirrored at , there is now a Shorewall mirror in Texas. + This web site is mirrored at http://www.infohiiway.com/shorewall - and the ftp site is at ftp://ftp.infohiiway.com/pub/mirrors/shorewall.
- +11/30/2001 - A new set of the parameterized Sample Configurations has been released. In this version:
- +-
- +- Ping is now allowed between - the zones.
-- In the three-interface configuration, - it is now possible to configure the internet services - that are to be available to servers in the DMZ.
+- Ping is now allowed +between the zones.
+- In the three-interface + configuration, it is now possible to configure the + internet services that are to be available to servers in +the DMZ.
- +11/20/2001 - The current version of Shorewall is 1.1.18.
- +In this version:
- +-
- +- The spelling of ADD_IP_ALIASES - has been corrected in the shorewall.conf file
-- The logic for deleting user-defined - chains has been simplified so that it avoids a bug in - the LRP version of the 'cut' utility.
-- The /var/lib/lrpkg/shorwall.conf - file has been corrected to properly display the NAT - entry in that file.
+- The spelling of ADD_IP_ALIASES + has been corrected in the shorewall.conf file
+- The logic for deleting + user-defined chains has been simplified so that it + avoids a bug in the LRP version of the 'cut' utility.
+- The /var/lib/lrpkg/shorwall.conf + file has been corrected to properly display the +NAT entry in that file.
- +11/19/2001 - Thanks to Juraj - Ontkanin, there is now a Shorewall mirror -in the Slovak Republic. The website is now mirrored -at http://www.nrg.sk/mirror/shorewall - and the FTP site is mirrored at , there is now a Shorewall mirror + in the Slovak Republic. The website is now mirrored + at http://www.nrg.sk/mirror/shorewall + and the FTP site is mirrored at ftp://ftp.nrg.sk/mirror/shorewall.
- +11/2/2001 - Announcing Shorewall Parameter-driven Sample Configurations. - There are three sample configurations:
+ There are three sample configurations: - +-
- +- One Interface -- for a standalone - system.
-- Two Interfaces -- A masquerading - firewall.
-- Three Interfaces -- A masquerading - firewall with DMZ.
+- One Interface -- for + a standalone system.
+- Two Interfaces -- A +masquerading firewall.
+- Three Interfaces -- +A masquerading firewall with DMZ.
- +Samples may be downloaded from ftp://ftp.shorewall.net/pub/shorewall/samples-1.1.17 - . See the README file for instructions.
+ . See the README file for instructions. - +11/1/2001 - The current version of Shorewall is 1.1.17. I intend - this to be the last of the 1.1 Shorewall releases.
+ this to be the last of the 1.1 Shorewall +releases. - +In this version:
- +-
- +- The handling of The handling of ADD_IP_ALIASES has - been corrected.
+ been corrected. - +10/22/2001 - The current version of Shorewall is 1.1.16. In this - version:
+ version: - +-
- +- A new "shorewall show connections" - command has been added.
-- In the "shorewall monitor" - output, the currently tracked connections are now -shown on a separate page.
-- Prior to this release, Shorewall - unconditionally added the external IP adddress(es) - specified in /etc/shorewall/nat. Beginning with version - 1.1.16, a new parameter (ADD_IP_ALIASES) - may be set to "no" (or "No") to inhibit this behavior. - This allows IP aliases created using your distribution's - network configuration tools to be used in static +
- A new "shorewall show + connections" command has been added.
+- In the "shorewall monitor" + output, the currently tracked connections are now + shown on a separate page.
+- Prior to this release, + Shorewall unconditionally added the external IP + adddress(es) specified in /etc/shorewall/nat. Beginning + with version 1.1.16, a new parameter (ADD_IP_ALIASES) may be + set to "no" (or "No") to inhibit this behavior. +This allows IP aliases created using your distribution's + network configuration tools to be used in static NAT.
- +10/15/2001 - The current version of Shorewall is 1.1.15. In this - version:
+ version: - +-
- +- Support for nested zones -has been improved. See - the documentation for details
-- Shorewall now correctly checks - the alternate configuration directory for the 'zones' - file.
+- Support for nested +zones has been improved. See the documentation for +details
+- Shorewall now correctly + checks the alternate configuration directory for + the 'zones' file.
- +10/4/2001 - The current version of Shorewall is 1.1.14. In this - version
+ version - +-
- +- Shorewall now supports alternate - configuration directories. When an alternate directory - is specified when starting or restarting Shorewall -(e.g., "shorewall -c /etc/testconf restart"), Shorewall will -first look for configuration files in the alternate directory then - in /etc/shorewall. To create an alternate configuration simply:
-
- 1. Create a New Directory
- 2. Copy to that directory any - of your configuration files that you want to change.
- 3. Modify the copied files -as needed.
- 4. Restart Shorewall specifying - the new directory.- The rules for allowing/disallowing - icmp echo-requests (pings) are now moved after rules - created when processing the rules file. This allows you to - add rules that selectively allow/deny ping based on source -or destination address.
-- Rules that specify multiple - client ip addresses or subnets no longer cause startup - failures.
-- Zone names in the policy -file are now validated against the zones file.
-- If you have Shorewall now supports + alternate configuration directories. When an alternate + directory is specified when starting or restarting Shorewall + (e.g., "shorewall -c /etc/testconf restart"), Shorewall + will first look for configuration files in the alternate directory + then in /etc/shorewall. To create an alternate configuration + simply:
+
+ 1. Create a New Directory
+ 2. Copy to that directory + any of your configuration files that you want to +change.
+ 3. Modify the copied +files as needed.
+ 4. Restart Shorewall +specifying the new directory.- The rules for allowing/disallowing + icmp echo-requests (pings) are now moved after +rules created when processing the rules file. This allows + you to add rules that selectively allow/deny ping based +on source or destination address.
+- Rules that specify +multiple client ip addresses or subnets no longer cause + startup failures.
+- Zone names in the policy + file are now validated against the zones file.
+- If you have packet mangling support - enabled, the "norfc1918" - interface option now logs and drops any incoming packets - on the interface that have an RFC 1918 destination address.
+ enabled, the "norfc1918" + interface option now logs and drops any incoming packets + on the interface that have an RFC 1918 destination + address. - +9/12/2001 - The current version of Shorewall is 1.1.13. In this - version
+ version - +-
- +- Shell variables can now be - used to parameterize Shorewall rules.
-- The second column in the -hosts file may now contain a comma-separated list.
-
-
- Example:
- sea eth0:130.252.100.0/24,206.191.149.0/24- Handling of multi-zone interfaces - has been improved. See the Shell variables can +now be used to parameterize Shorewall rules.
+- The second column in + the hosts file may now contain a comma-separated + list.
+
+
+ Example:
+ sea eth0:130.252.100.0/24,206.191.149.0/24- Handling of multi-zone + interfaces has been improved. See the documentation for the /etc/shorewall/interfaces - file.
+ file. - +8/28/2001 - The current version of Shorewall is 1.1.12. In this - version
+ version - +-
- +- Several columns in the rules - file may now contain comma-separated lists.
-- Shorewall is now more rigorous - in parsing the options in /etc/shorewall/interfaces.
-- Complementation using "!" -is now supported in rules.
+- Several columns in +the rules file may now contain comma-separated lists.
+- Shorewall is now more + rigorous in parsing the options in /etc/shorewall/interfaces.
+- Complementation using + "!" is now supported in rules.
- +7/28/2001 - The current version of Shorewall is 1.1.11. In this - version
+ version - +-
- +- A "shorewall refresh" command - has been added to allow for refreshing the rules associated - with the broadcast address on a dynamic interface. This - command should be used in place of "shorewall restart" when -the internet interface's IP address changes.
-- The /etc/shorewall/start -file (if any) is now processed after all temporary -rules have been deleted. This change prevents the accidental - removal of rules added during the processing of that file.
-- The "dhcp" interface option - is now applicable to firewall interfaces used by a DHCP - server running on the firewall.
-- The RPM can now be built -from the .tgz file using "rpm -tb"
+- A "shorewall refresh" + command has been added to allow for refreshing the + rules associated with the broadcast address on a dynamic + interface. This command should be used in place of "shorewall + restart" when the internet interface's IP address changes.
+- The /etc/shorewall/start + file (if any) is now processed after all temporary + rules have been deleted. This change prevents the accidental + removal of rules added during the processing of that + file.
+- The "dhcp" interface + option is now applicable to firewall interfaces used + by a DHCP server running on the firewall.
+- The RPM can now be +built from the .tgz file using "rpm -tb"
- +7/6/2001 - The current version of Shorewall is 1.1.10. In this version
- +-
- +- Shorewall now enables Ipv4 - Packet Forwarding by default. Packet forwarding may -be disabled by specifying IP_FORWARD=Off in /etc/shorewall/shorewall.conf. - If you don't want Shorewall to enable or disable packet - forwarding, add IP_FORWARDING=Keep to your /etc/shorewall/shorewall.conf - file.
-- The "shorewall hits" command - no longer lists extraneous service names in its last - report.
-- Erroneous instructions in -the comments at the head of the firewall script have -been corrected.
+- Shorewall now enables + Ipv4 Packet Forwarding by default. Packet forwarding + may be disabled by specifying IP_FORWARD=Off in /etc/shorewall/shorewall.conf. + If you don't want Shorewall to enable or disable packet + forwarding, add IP_FORWARDING=Keep to your /etc/shorewall/shorewall.conf + file.
+- The "shorewall hits" + command no longer lists extraneous service names +in its last report.
+- Erroneous instructions + in the comments at the head of the firewall script + have been corrected.
- +6/23/2001 - The current version of Shorewall is 1.1.9. In this version
- +-
- +- The "tunnels" file really - is in the RPM now.
-- SNAT can now be applied to - port-forwarded connections.
-- A bug which would cause firewall - start failures in some dhcp configurations has been - fixed.
-- The firewall script now issues - a message if you have the name of an interface in -the second column in an entry in /etc/shorewall/masq and -that interface is not up.
-- You can now configure Shorewall - so that it doesn't require the - NAT and/or mangle netfilter modules.
-- Thanks to Alex Polishchuk, - the "hits" command from seawall is now in shorewall.
-- Support for The "tunnels" file + really is in the RPM now.
+- SNAT can now be applied + to port-forwarded connections.
+- A bug which would cause + firewall start failures in some dhcp configurations + has been fixed.
+- The firewall script +now issues a message if you have the name of an interface + in the second column in an entry in /etc/shorewall/masq + and that interface is not up.
+- You can now configure + Shorewall so that it doesn't + require the NAT and/or mangle netfilter modules.
+- Thanks to Alex Polishchuk, + the "hits" command from seawall is now in shorewall.
+- Support for IPIP tunnels has been added.
- +6/18/2001 - The current version of Shorewall is 1.1.8. In this version
- +-
- +- A typo in the sample rules - file has been corrected.
-- It is now possible to restrict - masquerading by destination -host or subnet.
-- It is now possible to have - static NAT rules applied to packets - originating on the firewall itself.
+- A typo in the sample + rules file has been corrected.
+- It is now possible +to restrict masquerading by + destination host or subnet.
+- It is now possible +to have static NAT rules applied + to packets originating on the firewall itself.
- +6/2/2001 - The current version of Shorewall is 1.1.7. In this version
- +-
- +- The TOS rules are now deleted - when the firewall is stopped.
-- The .rpm will now install -regardless of which version of iptables is installed.
-- The .rpm will now install -without iproute2 being installed.
-- The documentation has been - cleaned up.
-- The sample configuration -files included in Shorewall have been formatted -to 80 columns for ease of editing on a VGA console.
+- The TOS rules are now + deleted when the firewall is stopped.
+- The .rpm will now install + regardless of which version of iptables is installed.
+- The .rpm will now install + without iproute2 being installed.
+- The documentation has + been cleaned up.
+- The sample configuration + files included in Shorewall have been formatted + to 80 columns for ease of editing on a VGA console.
- +5/25/2001 - The current version of Shorewall is 1.1.6. In this version
- +-
- +- You may now rate-limit the packet log.
-- Previous versions - of Shorewall have an implementation of Static NAT which violates - the principle of least surprise. NAT only occurs for packets - arriving at (DNAT) or send from (SNAT) the interface named - in the INTERFACE column of /etc/shorewall/nat. Beginning with - version 1.1.6, NAT effective regardless of which interface - packets come from or are destined to. To get compatibility with - prior versions, I have added a new "ALL Previous versions + of Shorewall have an implementation of Static NAT which + violates the principle of least surprise. NAT only occurs +for packets arriving at (DNAT) or send from (SNAT) the +interface named in the INTERFACE column of /etc/shorewall/nat. +Beginning with version 1.1.6, NAT effective regardless of +which interface packets come from or are destined to. To get +compatibility with prior versions, I have added a new "ALL "ALL INTERFACES" column to /etc/shorewall/nat. - By placing "no" or "No" in the new column, the NAT behavior - of prior versions may be retained.
-- The treatment of +
- The treatment of IPSEC Tunnels where the remote gateway is a standalone system has been improved. Previously, it was necessary to include an additional rule allowing UDP port 500 traffic @@ -2162,221 +2297,219 @@ to pass through the tunnel. Shorewall will now create this rule automatically when you place the name of the remote peer's zone in a new GATEWAY ZONE column in /etc/shorewall/tunnels.
- +5/20/2001 - The current version of Shorewall is 1.1.5. In this version
- +-
- +- You may now pass parameters when loading netfilter modules and you can specify the modules - to load.
-- Compressed modules are now - loaded. This requires that you modutils support loading - compressed modules.
-- +
- Compressed modules +are now loaded. This requires that you modutils support + loading compressed modules.
+- You may now set the Type of Service - (TOS) field in packets.
-- Corrected rules generated -for port redirection (again).
+ (TOS) field in packets. +- Corrected rules generated + for port redirection (again).
- +5/10/2001 - The current version of Shorewall is 1.1.4. In this version
- +-
- +- Accepting RELATED connections is now optional.
-- Corrected problem where if - "shorewall start" aborted early (due to kernel configuration - errors for example), superfluous 'sed' error messages - were reported.
-- Corrected rules generated -for port redirection.
-- The order in which iptables - kernel modules are loaded has been corrected (Thanks - to Mark Pavlidis).
+- Corrected problem where + if "shorewall start" aborted early (due to kernel +configuration errors for example), superfluous 'sed' error + messages were reported.
+- Corrected rules generated + for port redirection.
+- The order in which +iptables kernel modules are loaded has been corrected +(Thanks to Mark Pavlidis).
- +4/28/2001 - The current version of Shorewall is 1.1.3. In this version
- +-
- +- Correct message issued when - Proxy ARP address added (Thanks to Jason Kirtland).
-- /tmp/shorewallpolicy-$$ is - now removed if there is an error while starting the -firewall.
-- /etc/shorewall/icmp.def and - /etc/shorewall/common.def are now used to define the - icmpdef and common chains unless overridden by the presence - of /etc/shorewall/icmpdef or /etc/shorewall/common.
-- In the .lrp, the file /var/lib/lrpkg/shorwall.conf - has been corrected. An extra space after "/etc/shorwall/policy" - has been removed and "/etc/shorwall/rules" has been -added.
-- When a sub-shell encounters - a fatal error and has stopped the firewall, it now kills - the main shell so that the main shell will not continue.
-- A problem has been corrected - where a sub-shell stopped the firewall and main shell - continued resulting in a perplexing error message referring - to "common.so" resulted.
-- Previously, placing "-" in - the PORT(S) column in /etc/shorewall/rules resulted in - an error message during start. This has been corrected.
-- The first line of "install.sh" - has been corrected -- I had inadvertently deleted the -initial "#".
+- Correct message issued + when Proxy ARP address added (Thanks to Jason Kirtland).
+- /tmp/shorewallpolicy-$$ + is now removed if there is an error while starting +the firewall.
+- /etc/shorewall/icmp.def + and /etc/shorewall/common.def are now used to define + the icmpdef and common chains unless overridden by the + presence of /etc/shorewall/icmpdef or /etc/shorewall/common.
+- In the .lrp, the file + /var/lib/lrpkg/shorwall.conf has been corrected. An + extra space after "/etc/shorwall/policy" has been removed + and "/etc/shorwall/rules" has been added.
+- When a sub-shell encounters + a fatal error and has stopped the firewall, it now + kills the main shell so that the main shell will not continue.
+- A problem has been +corrected where a sub-shell stopped the firewall + and main shell continued resulting in a perplexing error +message referring to "common.so" resulted.
+- Previously, placing +"-" in the PORT(S) column in /etc/shorewall/rules resulted + in an error message during start. This has been corrected.
+- The first line of "install.sh" + has been corrected -- I had inadvertently deleted +the initial "#".
- +4/12/2001 - The current version of Shorewall is 1.1.2. In this version
- +-
- +- Port redirection now works - again.
-- The icmpdef and common chains - may now be user-defined.
-- The firewall no longer fails - to start if "routefilter" is specified for an interface - that isn't started. A warning message is now issued - in this case.
-- The LRP Version is renamed - "shorwall" for 8,3 MSDOS file system compatibility.
-- A couple of LRP-specific -problems were corrected.
+- Port redirection now + works again.
+- The icmpdef and common + chains may now be user-defined.
+- The firewall no longer + fails to start if "routefilter" is specified for +an interface that isn't started. A warning message is now + issued in this case.
+- The LRP Version is +renamed "shorwall" for 8,3 MSDOS file system compatibility.
+- A couple of LRP-specific + problems were corrected.
- +4/8/2001 - Shorewall is now affiliated with the Leaf Project
+ - +-
4/5/2001 - The current version of Shorewall is 1.1.1. In this version:
- +-
- +- The common chain is traversed - from INPUT, OUTPUT and FORWARD before logging occurs
-- The source has been cleaned - up dramatically
-- DHCP DISCOVER packets with - RFC1918 source addresses no longer generate log messages. - Linux DHCP clients generate such packets and it's - annoying to see them logged.
+- The common chain is +traversed from INPUT, OUTPUT and FORWARD before + logging occurs
+- The source has been +cleaned up dramatically
+- DHCP DISCOVER packets + with RFC1918 source addresses no longer generate +log messages. Linux DHCP clients generate such packets and + it's annoying to see them logged.
- +3/25/2001 - The current version of Shorewall is 1.1.0. In this version:
- +-
- +- Log messages now indicate -the packet disposition.
-- Error messages have been -improved.
-- The ability to define zones - consisting of an enumerated set of hosts and/or subnetworks - has been added.
-- The zone-to-zone chain matrix - is now sparse so that only those chains that contain - meaningful rules are defined.
-- 240.0.0.0/4 and 169.254.0.0/16 - have been added to the source subnetworks whose packets - are dropped under the norfc1918 interface - option.
-- Exits are now provided for - executing an user-defined script when a chain is -defined, when the firewall is initialized, when the firewall - is started, when the firewall is stopped and when the - firewall is cleared.
-- The Linux kernel's route -filtering facility can now be specified selectively -on network interfaces.
+- Log messages now indicate + the packet disposition.
+- Error messages have +been improved.
+- The ability to define + zones consisting of an enumerated set of hosts +and/or subnetworks has been added.
+- The zone-to-zone chain + matrix is now sparse so that only those chains + that contain meaningful rules are defined.
+- 240.0.0.0/4 and 169.254.0.0/16 + have been added to the source subnetworks whose +packets are dropped under the norfc1918 interface + option.
+- Exits are now provided + for executing an user-defined script when a chain + is defined, when the firewall is initialized, when the firewall + is started, when the firewall is stopped and when the + firewall is cleared.
+- The Linux kernel's +route filtering facility can now be specified + selectively on network interfaces.
- +3/19/2001 - The current version of Shorewall is 1.0.4. This version:
- +-
- +- Allows user-defined zones. - Shorewall now has only one pre-defined zone (fw) -with the remaining zones being defined in the new configuration - file /etc/shorewall/zones. The /etc/shorewall/zones - file released in this version provides behavior that -is compatible with Shorewall 1.0.3.
-- Adds the ability to specify - logging in entries in the /etc/shorewall/rules file.
-- Correct handling of the icmp-def - chain so that only ICMP packets are sent through -the chain.
-- Compresses the output of -"shorewall monitor" if awk is installed. Allows the -command to work if awk isn't installed (although it's -not pretty).
+- Allows user-defined +zones. Shorewall now has only one pre-defined zone +(fw) with the remaining zones being defined in the new configuration + file /etc/shorewall/zones. The /etc/shorewall/zones + file released in this version provides behavior that + is compatible with Shorewall 1.0.3.
+- Adds the ability to +specify logging in entries in the /etc/shorewall/rules + file.
+- Correct handling of +the icmp-def chain so that only ICMP packets are + sent through the chain.
+- Compresses the output + of "shorewall monitor" if awk is installed. Allows +the command to work if awk isn't installed (although it's + not pretty).
- +3/13/2001 - The current version of Shorewall is 1.0.3. This is a bug-fix - release with no new features.
+ release with no new features. - +-
- +- The PATH variable in the -firewall script now includes /usr/local/bin and -/usr/local/sbin.
-- DMZ-related chains are now - correctly deleted if the DMZ is deleted.
-- The interface OPTIONS for -"gw" interfaces are no longer ignored.
+- The PATH variable in + the firewall script now includes /usr/local/bin + and /usr/local/sbin.
+- DMZ-related chains +are now correctly deleted if the DMZ is deleted.
+- The interface OPTIONS + for "gw" interfaces are no longer ignored.
- +3/8/2001 - The current version of Shorewall is 1.0.2. It supports an - additional "gw" (gateway) zone for tunnels and it -supports IPSEC tunnels with end-points on the firewall. -There is also a .lrp available now.
+ additional "gw" (gateway) zone for tunnels and +it supports IPSEC tunnels with end-points on the firewall. + There is also a .lrp available now. - -Updated 2/7/2003 - Tom Eastep -
+ +Updated 2/13/2003 - Tom Eastep +
- +Copyright © 2001, 2002 Thomas M. Eastep.
-
-
-
-
-
+
diff --git a/Shorewall-docs/Shorewall_Squid_Usage.html b/Shorewall-docs/Shorewall_Squid_Usage.html index a310704f3..814a48dcd 100644 --- a/Shorewall-docs/Shorewall_Squid_Usage.html +++ b/Shorewall-docs/Shorewall_Squid_Usage.html @@ -2,368 +2,332 @@Shorewall Squid Usage - + - + - +- -
-- ++ + - -- -
-+
+Using Shorewall with Squid -
-+ - -
-
+ + + +
- This page covers Shorewall configuration to use with Squid running as a Transparent - Proxy.
-
-+ This page covers Shorewall configuration to use with Squid running as a Transparent + Proxy.
+
+- Please observe the following general requirements:
-
-- In all cases, Squid should be configured to run -as a transparent proxy as described at +
++ In all cases, Squid should be configured to run + as a transparent proxy as described at http://www.tldp.org/HOWTO/mini/TransparentProxy-4.html.
-
-- The following instructions mention the files /etc/shorewall/start - and /etc/shorewall/init -- if you don't have those files, siimply create -them.
-
-- When the Squid server is in the DMZ zone or in -the local zone, that zone must be defined ONLY by its interface -- no /etc/shorewall/hosts - file entries. That is because the packets being routed to the Squid server - still have their original destination IP addresses.
-
-- You must have iproute2 (ip utility) installed - on your firewall.
-
-- You must have iptables installed on your Squid -server.
-
-- You must have NAT and MANGLE enabled in your /etc/shorewall/conf - file
-
- NAT_ENABLED=Yes
- MANGLE_ENABLED=Yes
-
- Three different configurations are covered:
- +
++ The following instructions mention the files /etc/shorewall/start + and /etc/shorewall/init -- if you don't have those files, siimply create + them.
+
++ When the Squid server is in the DMZ zone or in + the local zone, that zone must be defined ONLY by its interface -- no /etc/shorewall/hosts + file entries. That is because the packets being routed to the Squid server + still have their original destination IP addresses.
+
++ You must have iproute2 (ip utility) installed + on your firewall.
+
++ You must have iptables installed on your Squid + server.
+
++ You must have NAT and MANGLE enabled in your +/etc/shorewall/conf file
+
+ NAT_ENABLED=Yes
+ MANGLE_ENABLED=Yes
+
+ Three different configurations are covered:
+-
- +- Squid running on the - Firewall.
-- Squid running in the +
- Squid running on +the Firewall.
+- Squid running in the local network
-- Squid running in the DMZ
- +- Squid running in the DMZ
+Squid Running on the Firewall
- You want to redirect all local www connection requests EXCEPT - those to your own - http server (206.124.146.177) - to a Squid transparent - proxy running on the firewall and listening on port 3128. Squid + You want to redirect all local www connection requests EXCEPT + those to your own + http server (206.124.146.177) + to a Squid transparent + proxy running on the firewall and listening on port 3128. Squid will of course require access to remote web servers.
-
- In /etc/shorewall/rules:
-
+
+ In /etc/shorewall/rules:
+
+ +++ ++ + +
++ +ACTION +SOURCE +DEST +PROTO +DEST +
+ PORT(S)SOURCE +
+ PORT(S)ORIGINAL + +
+ DEST+ +REDIRECT +loc +3128 +tcp +www +- +
+!206.124.146.177 ++ + + + + + + + + + +ACCEPT +fw +net +tcp +www ++
++
+
+Squid Running in the local network
+ You want to redirect all local www connection requests to a Squid + transparent proxy +running in your local zone at 192.168.1.3 and listening on port 3128. + Your local interface is eth1. There may also be a web server running on +192.168.1.3. It is assumed that web access is already enabled from the local +zone to the internet.
+ +WARNING: This setup may conflict with + other aspects of your gateway including but not limited to traffic shaping + and route redirection. For that reason, I don't recommend it.
+ +
++
+ +- On your firewall system, issue the following command
+ +
+++ +echo 202 www.out >> /etc/iproute2/rt_tables++
+ +- In /etc/shorewall/init, put:
+ +
+++ +if [ -z "`ip rule list | grep www.out`" ] ; then+
ip rule add fwmark 202 table www.out
ip route add default via 192.168.1.3 dev eth1 table www.out
ip route flush cache
echo 0 > /proc/sys/net/ipv4/conf/eth1/send_redirects
fi+
- In /etc/shorewall/rules:
+
+
+ ++ + +
++ +ACTION +SOURCE +DEST +PROTO +DEST +
+ PORT(S)SOURCE +
+ PORT(S)ORIGINAL + +
+ DEST+ + + + + + + + + + +ACCEPT +
+loc +loc +
+tcp +www ++
++
+
+- Alternativfely, you can have the following policy:
+
+
+ ++ +
++ +SOURCE +
+DESTINATION +
+POLICY +
+LOG LEVEL +
+BURST PARAMETERS +
++ + + +loc +
+loc +
+ACCEPT +
++
++
+
+- In /etc/shorewall/start add:
+ +
+--- - -
-- -ACTION -SOURCE -DEST -PROTO -DEST -
- PORT(S)SOURCE -
- PORT(S)ORIGINAL - -
- DEST- -REDIRECT -loc -3128 -tcp -www -- -
-!206.124.146.177 -- - - - - - - - - - -ACCEPT -fw -net -tcp -www --
--
-
+iptables -t mangle -A PREROUTING -i eth1 -s ! 192.168.1.3 -p tcp --dport 80 -j MARK --set-mark 202Squid Running in the local network
- You want to redirect all local www connection requests to a Squid - transparent proxy - running in your local zone at 192.168.1.3 and listening on port 3128. -Your local interface is eth1. There may also be a web server running on 192.168.1.3. -It is assumed that web access is already enabled from the local zone to the -internet.
- -WARNING: This setup may conflict with - other aspects of your gateway including but not limited to traffic shaping - and route redirection. For that reason, I don't recommend it.
-
--
- -- On your firewall system, issue the following command
- -
--- -echo 202 www.out >> /etc/iproute2/rt_tables--
- -- In /etc/shorewall/init, put:
- -
--- -if [ -z "`ip rule list | grep www.out`" ] ; then-
ip rule add fwmark 202 table www.out
ip route add default via 192.168.1.3 dev eth1 table www.out
ip route flush cache
echo 0 > /proc/sys/net/ipv4/conf/eth1/send_redirects
fi-
- -- In /etc/shorewall/rules:
-
-
- -- - -
-- -ACTION -SOURCE -DEST -PROTO -DEST -
- PORT(S)SOURCE -
- PORT(S)ORIGINAL - -
- DEST- - - - - - - - - - -ACCEPT -
-loc -loc -
-tcp -www --
--
-
-- Alternativfely, you can have the following policy:
-
-
- -- -
-- -SOURCE -
-DESTINATION -
-POLICY -
-LOG LEVEL -
-BURST PARAMETERS -
-- - - -loc -
-loc -
-ACCEPT -
--
--
-
-- In /etc/shorewall/start add:
- -
--- -iptables -t mangle -A PREROUTING -i eth1 -s ! 192.168.1.3 -p tcp --dport 80 -j MARK --set-mark 202--
- -- On 192.168.1.3, arrange for the following command to be executed +
- On 192.168.1.3, arrange for the following command to be executed after networking has come up
- + +
- +iptables -t nat -A PREROUTING -i eth0 -d ! 192.168.1.3 -p tcp --dport 80 -j REDIRECT --to-ports 3128-If you are running RedHat on the server, you can simply execute - the following commands after you have typed the iptables command above:-
-++If you are running RedHat on the server, you can simply execute + the following commands after you have typed the iptables command above:+ +
+- +- +iptables-save > /etc/sysconfig/iptables-
chkconfig --level 35 iptables start- +Squid Running in the DMZ (This is what I do)
- You have a single Linux system in your DMZ with IP address 192.0.2.177. - You want to run both a web server and Squid on that system. Your DMZ interface + You have a single Linux system in your DMZ with IP address 192.0.2.177. + You want to run both a web server and Squid on that system. Your DMZ interface is eth1 and your local interface is eth2.
- +-
- -- On your firewall system, issue the following command
- +
-- On your firewall system, issue the following command
+
++ ++- +echo 202 www.out >> /etc/iproute2/rt_tables--
+ +- In /etc/shorewall/init, put:
+
-- In /etc/shorewall/init, put:
+ +
+++ +if [ -z "`ip rule list | grep www.out`" ] ; then+
ip rule add fwmark 202 table www.out
ip route add default via 192.0.2.177 dev eth1 table www.out
ip route flush cache
fi+
- -- Do one of the following:
+
+ A) In /etc/shorewall/start add
+-- -if [ -z "`ip rule list | grep www.out`" ] ; then-
ip rule add fwmark 202 table www.out
ip route add default via 192.0.2.177 dev eth1 table www.out
ip route flush cache
fi-
- -- Do one of the following:
- -
-
-A) In /etc/shorewall/start add
-+ ++- -iptables -t nat -A PREROUTING -i eth2 -p tcp --dport 80 -j MARK --set-mark 202-B) Set MARK_IN_FORWARD_CHAIN=No in /etc/shorewall/shorewall.conf ++ +B) Set MARK_IN_FORWARD_CHAIN=No in /etc/shorewall/shorewall.conf and add the following entry in /etc/shorewall/tcrules:-
--+--C) Run Shorewall 1.3.14 or later and add the following entry in /etc/shorewall/tcrules:- -
-- -MARK -
-SOURCE -
-DESTINATION -
-PROTOCOL -
-PORT -
-CLIENT PORT -
-- - -202 -
-eth2 -
-0.0.0.0/0 -
-tcp -
-80 -
-- -
-
-+ C) Run Shorewall 1.3.14 or later and add the following entry in /etc/shorewall/tcrules:-@@ -383,7 +347,7 @@ C) Run Shorewall 1.3.14 or later and add the following entry in /etc/shorewall/t
- 202:P
+202
eth2 @@ -400,90 +364,130 @@ C) Run Shorewall 1.3.14 or later and add the following entry in /etc/shorewall/t
-
+ + ++++++ +
++ +MARK +
+SOURCE +
+DESTINATION +
+PROTOCOL +
+PORT +
+CLIENT PORT +
++ + + +202:P +
+eth2 +
+0.0.0.0/0 +
+tcp +
+80 +
+- +
+
+-
- -- In /etc/shorewall/rules, you will need:
- --- -- -
-- -ACTION -
-SOURCE -
-DEST -
-PROTO -
-DEST -
- PORT(S)
-CLIENT -
- PORT(2)
-ORIGINAL -
- DEST
-- - - -ACCEPT -
-dmz -
-net -
-tcp -
-80 -
--
--
-
--
- -- On 192.0.2.177 (your Web/Squid server), arrange for the following - command to be executed after networking has come up
+
- -iptables -t nat -A PREROUTING -i eth0 -d ! 192.0.2.177 -p tcp --dport 80 -j REDIRECT --to-ports 3128-- In /etc/shorewall/rules, you will need:
If you are running RedHat on the server, you can simply execute - the following commands after you have typed the iptables command above:- +
-++ ++ +
++ +ACTION +
+SOURCE +
+DEST +
+PROTO +
+DEST +
+ PORT(S)
+CLIENT +
+ PORT(2)
+ORIGINAL +
+ DEST
++ + + +ACCEPT +
+dmz +
+net +
+tcp +
+80 +
++
++
+
++
+ +- On 192.0.2.177 (your Web/Squid server), arrange for the following + command to be executed after networking has come up
+ +
+ +iptables -t nat -A PREROUTING -i eth0 -d ! 192.0.2.177 -p tcp --dport 80 -j REDIRECT --to-ports 3128+If you are running RedHat on the server, you can simply execute + the following commands after you have typed the iptables command above:+ +
+- + +- +iptables-save > /etc/sysconfig/iptables-
chkconfig --level 35 iptables start- -Updated 1/23/2003 - Tom Eastep -
+ +Updated 1/23/2003 - Tom Eastep +
- Copyright © 2003 Thomas M. Eastep.
-
-
-
+
+
+
+
diff --git a/Shorewall-docs/configuration_file_basics.htm b/Shorewall-docs/configuration_file_basics.htm index 2e6379b18..2ee3e74f0 100644 --- a/Shorewall-docs/configuration_file_basics.htm +++ b/Shorewall-docs/configuration_file_basics.htm @@ -1,343 +1,344 @@ - + - + - + - +Configuration File Basics - +- -
+ +- ++ + + + ++ + + +Configuration Files
+Warning: If you copy or edit your + configuration files on a system running Microsoft Windows, you must + run them through dos2unix + before you use them with Shorewall.
+ +Files
+ +Shorewall's configuration files are in the directory /etc/shorewall.
+ ++
+ +- /etc/shorewall/shorewall.conf - used to set +several firewall parameters.
+- /etc/shorewall/params - use this file to set +shell variables that you will expand in other files.
+- /etc/shorewall/zones - partition the firewall's + view of the world into zones.
+- /etc/shorewall/policy - establishes firewall +high-level policy.
+- /etc/shorewall/interfaces - describes the interfaces + on the firewall system.
+- /etc/shorewall/hosts - allows defining zones +in terms of individual hosts and subnetworks.
+- /etc/shorewall/masq - directs the firewall where + to use many-to-one (dynamic) Network Address Translation (a.k.a. + Masquerading) and Source Network Address Translation (SNAT).
+- /etc/shorewall/modules - directs the firewall + to load kernel modules.
+- /etc/shorewall/rules - defines rules that are + exceptions to the overall policies established in /etc/shorewall/policy.
+- /etc/shorewall/nat - defines static NAT rules.
+- /etc/shorewall/proxyarp - defines use of Proxy + ARP.
+- /etc/shorewall/routestopped (Shorewall 1.3.4 +and later) - defines hosts accessible when Shorewall is stopped.
+- /etc/shorewall/tcrules - defines marking of +packets for later use by traffic control/shaping or policy routing.
+- /etc/shorewall/tos - defines rules for setting + the TOS field in packet headers.
+- /etc/shorewall/tunnels - defines IPSEC, GRE +and IPIP tunnels with end-points on the firewall system.
+- /etc/shorewall/blacklist - lists blacklisted +IP/subnet/MAC addresses.
+- /etc/shorewall/init - commands that you wish to execute at the +beginning of a "shorewall start" or "shorewall restart".
+- /etc/shorewall/start - commands that you wish to execute at the +completion of a "shorewall start" or "shorewall restart"
+- /etc/shorewall/stop - commands that you wish to execute at the +beginning of a "shorewall stop".
+- /etc/shorewall/stopped - commands that you wish to execute at the + completion of a "shorewall stop".
+ +
+Comments
+ +You may place comments in configuration files by making the first non-whitespace + character a pound sign ("#"). You may also place comments at + the end of any line, again by delimiting the comment from the rest + of the line with a pound sign.
+ +Examples:
+ +# This is a comment+ +ACCEPT net fw tcp www #This is an end-of-line comment+ +Line Continuation
+ +You may continue lines in the configuration files using the usual backslash + ("\") followed immediately by a new line character.
+ +Example:
+ +ACCEPT net fw tcp \+ +
smtp,www,pop3,imap #Services running on the firewallUsing DNS Names
+ ++ +
WARNING: I personally recommend strongly against + using DNS names in Shorewall configuration files. If you use DNS names + and you are called out of bed at 2:00AM because Shorewall won't start + as a result of DNS problems then don't say that you were not forewarned. +
+ +
+-Tom
+ +
+Beginning with Shorwall 1.3.9, Host addresses in Shorewall + configuration files may be specified as either IP addresses or DNS + Names.
+ +
+
+ DNS names in iptables rules aren't nearly as useful as they + first appear. When a DNS name appears in a rule, the iptables utility + resolves the name to one or more IP addresses and inserts those +addresses into the rule. So changes in the DNS->IP address relationship + that occur after the firewall has started have absolutely no effect +on the firewall's ruleset.If your firewall rules include DNS names then:
+ ++
+ +- If your /etc/resolv.conf is wrong then your firewall + won't start.
+- If your /etc/nsswitch.conf is wrong then your firewall + won't start.
+- If your Name Server(s) is(are) down then your firewall + won't start.
+- If your startup scripts try to start your firewall +before starting your DNS server then your firewall won't start.
+
+- Factors totally outside your control (your ISP's router + is down for example), can prevent your firewall from starting.
+- You must bring up your network interfaces prior to starting + your firewall.
+ +
+Each DNS name much be fully qualified and include a minumum + of two periods (although one may be trailing). This restriction is + imposed by Shorewall to insure backward compatibility with existing + configuration files.
+ +
+
+ Examples of valid DNS names:
++
+ Examples of invalid DNS names:- mail.shorewall.net
+- shorewall.net. (note the trailing period).
+ +
+ ++
+ DNS names may not be used as:- mail (not fully qualified)
+- shorewall.net (only one period)
+ +
+ ++
+ These restrictions are not imposed by Shorewall simply for + your inconvenience but are rather limitations of iptables.- The server address in a DNAT rule (/etc/shorewall/rules + file)
+- In the ADDRESS column of an entry in /etc/shorewall/masq.
+- In the /etc/shorewall/nat file.
+ +
+ +Complementing an Address or Subnet
+ +Where specifying an IP address, a subnet or an interface, you can + precede the item with "!" to specify the complement of the item. For + example, !192.168.1.4 means "any host but 192.168.1.4". There must +be no white space following the "!".
+ +Comma-separated Lists
+ +Comma-separated lists are allowed in a number of contexts within the + configuration files. A comma separated list:
+ ++
+ +- Must not have any embedded white space.
+
+ Valid: routefilter,dhcp,norfc1918
+ Invalid: routefilter, dhcp, norfc1818- If you use line continuation to break a comma-separated + list, the continuation line(s) must begin in column 1 (or + there would be embedded white space)
+- Entries in a comma-separated list may appear +in any order.
+ +Port Numbers/Service Names
+ +Unless otherwise specified, when giving a port number you can use + either an integer or a service name from /etc/services.
+ +Port Ranges
+ +If you need to specify a range of ports, the proper syntax is <low + port number>:<high port number>. For example, + if you want to forward the range of tcp ports 4000 through 4100 to +local host 192.168.1.3, the entry in /etc/shorewall/rules is:
+ +
+DNAT net loc:192.168.1.3 tcp 4000:4100+ If you omit the low port number, a value of zero is assumed; if you omit +the high port number, a value of 65535 is assumed.
+ +Using Shell Variables
+ +You may use the /etc/shorewall/params file to set shell variables + that you can then use in some of the other configuration files.
+ +It is suggested that variable names begin with an upper case letter to distinguish them from variables used internally + within the Shorewall programs
+ +Example:
+ ++ ++ +NET_IF=eth0+
NET_BCAST=130.252.100.255
NET_OPTIONS=routefilter,norfc1918+ + +
+ Example (/etc/shorewall/interfaces record):+ ++ + +net $NET_IF $NET_BCAST $NET_OPTIONS+The result will be the same as if the record had been written
+ + ++ ++ -net eth0 130.252.100.255 routefilter,norfc1918+Configuration Files
- - - - -Warning: If you copy or edit your - configuration files on a system running Microsoft Windows, you must - run them through dos2unix - before you use them with Shorewall.
- -Files
- -Shorewall's configuration files are in the directory /etc/shorewall.
- --
- -- /etc/shorewall/shorewall.conf - used to set several - firewall parameters.
-- /etc/shorewall/params - use this file to set -shell variables that you will expand in other files.
-- /etc/shorewall/zones - partition the firewall's - view of the world into zones.
-- /etc/shorewall/policy - establishes firewall -high-level policy.
-- /etc/shorewall/interfaces - describes the interfaces - on the firewall system.
-- /etc/shorewall/hosts - allows defining zones -in terms of individual hosts and subnetworks.
-- /etc/shorewall/masq - directs the firewall where - to use many-to-one (dynamic) Network Address Translation -(a.k.a. Masquerading) and Source Network Address Translation -(SNAT).
-- /etc/shorewall/modules - directs the firewall -to load kernel modules.
-- /etc/shorewall/rules - defines rules that are -exceptions to the overall policies established in /etc/shorewall/policy.
-- /etc/shorewall/nat - defines static NAT rules.
-- /etc/shorewall/proxyarp - defines use of Proxy - ARP.
-- /etc/shorewall/routestopped (Shorewall 1.3.4 -and later) - defines hosts accessible when Shorewall is stopped.
-- /etc/shorewall/tcrules - defines marking of packets - for later use by traffic control/shaping or policy routing.
-- /etc/shorewall/tos - defines rules for setting - the TOS field in packet headers.
-- /etc/shorewall/tunnels - defines IPSEC, GRE and - IPIP tunnels with end-points on the firewall system.
-- /etc/shorewall/blacklist - lists blacklisted -IP/subnet/MAC addresses.
-- /etc/shorewall/init - commands that you wish to execute at the beginning - of a "shorewall start" or "shorewall restart".
-- /etc/shorewall/start - commands that you wish to execute at the -completion of a "shorewall start" or "shorewall restart"
-- /etc/shorewall/stop - commands that you wish to execute at the beginning - of a "shorewall stop".
-- /etc/shorewall/stopped - commands that you wish to execute at the - completion of a "shorewall stop".
- -
-Comments
- -You may place comments in configuration files by making the first non-whitespace - character a pound sign ("#"). You may also place comments at - the end of any line, again by delimiting the comment from the -rest of the line with a pound sign.
- -Examples:
- -# This is a comment- -ACCEPT net fw tcp www #This is an end-of-line comment- -Line Continuation
- -You may continue lines in the configuration files using the usual backslash - ("\") followed immediately by a new line character.
- -Example:
- -ACCEPT net fw tcp \- -
smtp,www,pop3,imap #Services running on the firewallUsing DNS Names
- -- -
WARNING: I personally recommend strongly against - using DNS names in Shorewall configuration files. If you use DNS -names and you are called out of bed at 2:00AM because Shorewall won't -start as a result of DNS problems then don't say that you were not forewarned. -
- -
--Tom
- -
-Beginning with Shorwall 1.3.9, Host addresses in Shorewall - configuration files may be specified as either IP addresses or DNS - Names.
- -
-
- DNS names in iptables rules aren't nearly as useful as they - first appear. When a DNS name appears in a rule, the iptables utility - resolves the name to one or more IP addresses and inserts those addresses - into the rule. So changes in the DNS->IP address relationship that - occur after the firewall has started have absolutely no effect on the - firewall's ruleset.If your firewall rules include DNS names then:
- --
- -- If your /etc/resolv.conf is wrong then your firewall -won't start.
-- If your /etc/nsswitch.conf is wrong then your firewall - won't start.
-- If your Name Server(s) is(are) down then your firewall - won't start.
-- If your startup scripts try to start your firewall before - starting your DNS server then your firewall won't start.
-
-- Factors totally outside your control (your ISP's router - is down for example), can prevent your firewall from starting.
-- You must bring up your network interfaces prior to starting - your firewall.
- -
-Each DNS name much be fully qualified and include a minumum - of two periods (although one may be trailing). This restriction is -imposed by Shorewall to insure backward compatibility with existing -configuration files.
- -
-
- Examples of valid DNS names:
--
- Examples of invalid DNS names:- mail.shorewall.net
-- shorewall.net. (note the trailing period).
- -
- --
- DNS names may not be used as:- mail (not fully qualified)
-- shorewall.net (only one period)
- -
- --
- These restrictions are not imposed by Shorewall simply for - your inconvenience but are rather limitations of iptables.- The server address in a DNAT rule (/etc/shorewall/rules - file)
-- In the ADDRESS column of an entry in /etc/shorewall/masq.
-- In the /etc/shorewall/nat file.
- -
- -Complementing an Address or Subnet
- -Where specifying an IP address, a subnet or an interface, you can - precede the item with "!" to specify the complement of the item. For - example, !192.168.1.4 means "any host but 192.168.1.4". There must be -no white space following the "!".
- -Comma-separated Lists
- -Comma-separated lists are allowed in a number of contexts within the - configuration files. A comma separated list:
- --
- -- Must not have any embedded white space.
-
- Valid: routestopped,dhcp,norfc1918
- Invalid: routestopped, dhcp, norfc1818- If you use line continuation to break a comma-separated - list, the continuation line(s) must begin in column 1 (or -there would be embedded white space)
-- Entries in a comma-separated list may appear -in any order.
- -Port Numbers/Service Names
- -Unless otherwise specified, when giving a port number you can use - either an integer or a service name from /etc/services.
- -Port Ranges
- -If you need to specify a range of ports, the proper syntax is <low - port number>:<high port number>. For example, - if you want to forward the range of tcp ports 4000 through 4100 to local - host 192.168.1.3, the entry in /etc/shorewall/rules is:
- -
-DNAT net loc:192.168.1.3 tcp 4000:4100-If you omit the low port number, a value of zero is assumed; if you omit -the high port number, a value of 65535 is assumed.
- -Using Shell Variables
- -You may use the /etc/shorewall/params file to set shell variables - that you can then use in some of the other configuration files.
- -It is suggested that variable names begin with an upper case letter to distinguish them from variables used internally - within the Shorewall programs
- -Example:
- -- -- -NET_IF=eth0-
NET_BCAST=130.252.100.255
NET_OPTIONS=noping,norfc1918- - -
- Example (/etc/shorewall/interfaces record):- -- - -net $NET_IF $NET_BCAST $NET_OPTIONS-The result will be the same as if the record had been written
- - -- -- - -net eth0 130.252.100.255 noping,norfc1918-Variables may be used anywhere in the other configuration - files.
- +Variables may be used anywhere in the other configuration + files.
+Using MAC Addresses
- -Media Access Control (MAC) addresses can be used to specify packet - source in several of the configuration files. To use this feature, - your kernel must have MAC Address Match support (CONFIG_IP_NF_MATCH_MAC) - included.
- -MAC addresses are 48 bits wide and each Ethernet Controller has a - unique MAC address.
-
- In GNU/Linux, MAC addresses are usually written as + +Media Access Control (MAC) addresses can be used to specify packet + source in several of the configuration files. To use this +feature, your kernel must have MAC Address Match support (CONFIG_IP_NF_MATCH_MAC) + included.
+ +MAC addresses are 48 bits wide and each Ethernet Controller has a + unique MAC address.
- -
+
+ In GNU/Linux, MAC addresses are usually written as a series of 6 hex numbers separated by colons. Example:
-
- [root@gateway root]# ifconfig eth0
- eth0 Link encap:Ethernet HWaddr 02:00:08:E3:FA:55
- inet addr:206.124.146.176 Bcast:206.124.146.255 - Mask:255.255.255.0
- UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
- RX packets:2398102 errors:0 dropped:0 overruns:0 - frame:0
- TX packets:3044698 errors:0 dropped:0 overruns:0 - carrier:0
- collisions:30394 txqueuelen:100
- RX bytes:419871805 (400.4 Mb) TX bytes:1659782221 - (1582.8 Mb)
- Interrupt:11 Base address:0x1800
-
- Because Shorewall uses colons as a separator for address - fields, Shorewall requires MAC addresses to be written in another - way. In Shorewall, MAC addresses begin with a tilde ("~") and -consist of 6 hex numbers separated by hyphens. In Shorewall, the +
+ [root@gateway root]# ifconfig eth0
+ eth0 Link encap:Ethernet HWaddr 02:00:08:E3:FA:55
+ inet addr:206.124.146.176 Bcast:206.124.146.255 + Mask:255.255.255.0
+ UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
+ RX packets:2398102 errors:0 dropped:0 overruns:0 + frame:0
+ TX packets:3044698 errors:0 dropped:0 overruns:0 + carrier:0
+ collisions:30394 txqueuelen:100
+ RX bytes:419871805 (400.4 Mb) TX bytes:1659782221 + (1582.8 Mb)
+ Interrupt:11 Base address:0x1800
+
+ Because Shorewall uses colons as a separator for address + fields, Shorewall requires MAC addresses to be written in another + way. In Shorewall, MAC addresses begin with a tilde ("~") and +consist of 6 hex numbers separated by hyphens. In Shorewall, the MAC address in the example above would be written "~02-00-08-E3-FA-55".
-Note: It is not necessary to use the special Shorewall notation - in the /etc/shorewall/maclist file.
- + + +
-Note: It is not necessary to use the special Shorewall notation + in the /etc/shorewall/maclist file.
+
+Shorewall Configurations
- -Shorewall allows you to have configuration directories other than /etc/shorewall. - The shorewall start and - restart commands allow you to specify an alternate configuration - directory and Shorewall will use the files in the alternate directory - rather than the corresponding files in /etc/shorewall. The alternate directory - need not contain a complete configuration; those files not in the alternate - directory will be read from /etc/shorewall.
- -This facility permits you to easily create a test or temporary configuration - by:
- + +Shorewall allows you to have configuration directories other than /etc/shorewall. + The shorewall start +and restart commands allow you to specify an alternate configuration + directory and Shorewall will use the files in the alternate directory + rather than the corresponding files in /etc/shorewall. The alternate +directory need not contain a complete configuration; those files not +in the alternate directory will be read from /etc/shorewall.
+ +This facility permits you to easily create a test or temporary configuration + by:
+-
- -- copying the files that need modification from - /etc/shorewall to a separate directory;
-- modify those files in the separate directory; - and
-- specifying the separate directory in a shorewall - start or shorewall restart command (e.g., shorewall -c /etc/testconfig - restart ).
- +- copying the files that need modification from + /etc/shorewall to a separate directory;
+- modify those files in the separate directory; + and
+- specifying the separate directory in a shorewall + start or shorewall restart command (e.g., shorewall -c /etc/testconfig + restart ).
+Updated 2/7/2003 - Tom Eastep + +
+ +Updated 2/7/2003 - Tom Eastep
- -Copyright - © 2001, 2002, 2003 Thomas M. Eastep.
+ +
-Copyright + © 2001, 2002, 2003 Thomas M. Eastep.
+
+
diff --git a/Shorewall-docs/errata.htm b/Shorewall-docs/errata.htm index 5a2a445dd..628748a58 100644 --- a/Shorewall-docs/errata.htm +++ b/Shorewall-docs/errata.htm @@ -2,657 +2,244 @@ - + -Shorewall 1.3 Errata +Shorewall 1.4 Errata - + + - + - + + + - +- -
- +- ++ + + + - - + +- + -Shorewall Errata/Upgrade Issues
-IMPORTANT
- +- +
-If you are installing Shorewall for the first time and plan to use the .tgz and install.sh script, you can untar the archive, replace the 'firewall' script in the untarred directory - with the one you downloaded below, and then run install.sh.
-- - -
-If you are running a Shorewall version earlier - than 1.3.11, when the instructions say to install a corrected firewall - script in /etc/shorewall/firewall, /usr/lib/shorewall/firewall - or /var/lib/shorewall/firewall, use the 'cp' (or 'scp') utility to -overwrite the existing file. DO NOT REMOVE OR RENAME THE OLD -/etc/shorewall/firewall or /var/lib/shorewall/firewall before -you do that. /etc/shorewall/firewall and /var/lib/shorewall/firewall - are symbolic links that point to the 'shorewall' file used by -your system initialization scripts to start Shorewall during -boot. It is that file that must be overwritten with the corrected -script. Beginning with Shorewall 1.3.11, you may rename the existing file -before copying in the new file.
-- - + with the one you downloaded below, and then run install.sh. +
+- + +
+When the instructions say to install a corrected + firewall script in /usr/share/shorewall/firewall, you may +rename the existing file before copying in the new file.
+- +
- + ON A RELEASE EARLIER THAN THE ONE THAT THEY ARE LISTED UNDER BELOW. + For example, do NOT install the 1.3.9a firewall script if you are running + 1.3.7c.DO NOT INSTALL CORRECTED COMPONENTS - ON A RELEASE EARLIER THAN THE ONE THAT THEY ARE LISTED UNDER BELOW. -For example, do NOT install the 1.3.9a firewall script if you are running - 1.3.7c.
-
-
+ + + - +-
- -- Upgrade Issues
-- Problems - in Version 1.3
-- Upgrade Issues
+- Problems in Version 1.4
+
+- Problems in Version 1.3
+- Problems in Version 1.2
-- Problems in Version 1.1
-- Problem with iptables version 1.2.3 - on RH7.2
-- +
- Problems with kernels >= 2.4.18 and RedHat iptables
-- Problems installing/upgrading - RPM on SuSE
-- Problems with iptables -version 1.2.7 and MULTIPORT=Yes
-- Problems with RH Kernel 2.4.18-10 and - NAT
- +
-- Problems installing/upgrading + RPM on SuSE
+- Problems with iptables + version 1.2.7 and MULTIPORT=Yes
+- Problems with RH Kernel 2.4.18-10 +and NAT
+
+
-Problems in Version 1.3
- - -Version 1.3.13
- --
- All three problems are corrected by this - firewall script which may be installed in /usr/lib/shorewall as described - above.- The 'shorewall add' command produces an error message referring -to 'find_interfaces_by_maclist'.
-- The 'shorewall delete' command can leave behind undeleted rules.
-- The 'shorewall add' command can fail with "iptables: Index of insertion -too big".
- -
-
- --
- -- VLAN interface names of the form "ethn.m" (e.g., eth0.1) -are not supported in this version or in 1.3.12. If you need such support, -post on the users list and I can provide you with a patched version.
- -
-Version 1.3.12
- --
- -- If RFC_1918_LOG_LEVEL is set to anything but ULOG, the effect is - the same as if RFC_1918_LOG_LEVEL=info had been specified. The problem -is corrected by this - firewall script which may be installed in /usr/lib/shorewall as described - above.
-- VLAN interface names of the form "ethn.m" (e.g., eth0.1) - are not supported in this version or in 1.3.13. If you need such support, - post on the users list and I can provide you with a patched version.
- -
-Version 1.3.12 LRP
- --
- -- The .lrp was missing the /etc/shorewall/routestopped file -- a -new lrp (shorwall-1.3.12a.lrp) has been released which corrects this problem.
- -
-Version 1.3.11a
- --
- -- This - copy of /etc/shorewall/rfc1918 reflects the recent allocation of 82.0.0.0/8.
- -
-Version 1.3.11
- --
- -- When installing/upgrading using the .rpm, you may receive -the following warnings:
-
-
- user teastep does not exist - using root
- group teastep does not exist - using root
-
- These warnings are harmless and may be ignored. Users downloading - the .rpm from shorewall.net or mirrors should no longer see these warnings - as the .rpm you will get from there has been corrected.- DNAT rules that exclude a source subzone (SOURCE column contains - ! followed by a sub-zone list) result in an error message and Shorewall - fails to start.
- -
-
- Install this - corrected script in /usr/lib/shorewall/firewall to correct this problem. - Thanks go to Roger Aich who analyzed this problem and provided a fix.
-
- This problem is corrected in version 1.3.11a.
-Version 1.3.10
- --
- -- If you experience problems connecting to a PPTP server running - on your firewall and you have a 'pptpserver' entry in /etc/shorewall/tunnels, - this - version of the firewall script may help. Please report any cases -where installing this script in /usr/lib/shorewall/firewall solved your -connection problems. Beginning with version 1.3.10, it is safe to save -the old version of /usr/lib/shorewall/firewall before copying in the -new one since /usr/lib/shorewall/firewall is the real script now and -not just a symbolic link to the real script.
- -
-Version 1.3.9a
- --
- -- If entries are used in /etc/shorewall/hosts and MERGE_HOSTS=No - then the following message appears during "shorewall [re]start":
- -recalculate_interfacess: command not found- -The updated firewall script at ftp://www.shorewall.net/pub/shorewall/errata/1.3.9/firewall - corrects this problem.Copy the script to /usr/lib/shorewall/firewall - as described above.- -
-Alternatively, edit /usr/lob/shorewall/firewall and change the - single occurence (line 483 in version 1.3.9a) of 'recalculate_interefacess' - to 'recalculate_interface'.- -
--
- -- The installer (install.sh) issues a misleading message -"Common functions installed in /var/lib/shorewall/functions" whereas -the file is installed in /usr/lib/shorewall/functions. The installer -also performs incorrectly when updating old configurations that had the -file /etc/shorewall/functions. Here - is an updated version that corrects these problems.
- -
-Version 1.3.9
- TUNNELS Broken in 1.3.9!!! There is an updated firewall - script at ftp://www.shorewall.net/pub/shorewall/errata/1.3.9/firewall - -- copy that file to /usr/lib/shorewall/firewall as described above.
-
- Version 1.3.8 --
- Installing - this corrected firewall script in /var/lib/shorewall/firewall - as described above corrects these -problems. -- Use of shell variables in the LOG LEVEL or SYNPARMS - columns of the policy file doesn't work.
-- A DNAT rule with the same original and new IP addresses - but with different port numbers doesn't work (e.g., "DNAT loc dmz:10.1.1.1:24 - tcp 25 - 10.1.1.1")
- -
-Version 1.3.7b
- -DNAT rules where the source zone is 'fw' ($FW) - result in an error message. Installing - - this corrected firewall script in /var/lib/shorewall/firewall - as described above corrects this -problem.
- -Version 1.3.7a
- -"shorewall refresh" is not creating the proper - rule for FORWARDPING=Yes. Consequently, after - "shorewall refresh", the firewall will not forward - icmp echo-request (ping) packets. Installing - - this corrected firewall script in /var/lib/shorewall/firewall - as described above corrects this -problem.
- -Version <= 1.3.7a
- -If "norfc1918" and "dhcp" are both specified as - options on a given interface then RFC 1918 - checking is occurring before DHCP checking. This - means that if a DHCP client broadcasts using an - RFC 1918 source address, then the firewall will - reject the broadcast (usually logging it). This - has two problems:
- --
- - -- If the firewall is -running a DHCP server, the client -won't be able to obtain an IP address - lease from that server.
-- With this order of -checking, the "dhcp" option cannot -be used as a noise-reduction measure -where there are both dynamic and static - clients on a LAN segment.
- -- This version of the 1.3.7a firewall script - corrects the problem. It must be installed - in /var/lib/shorewall as described - above.
- -Version 1.3.7
- -Version 1.3.7 dead on arrival -- please use - version 1.3.7a and check your version against - these md5sums -- if there's a difference, please - download again.
- -d2fffb7fb99bcc6cb047ea34db1df10 shorewall-1.3.7a.tgz- -
6a7fd284c8685b2b471a2f47b469fb94 shorewall-1.3.7a-1.noarch.rpm
3decd14296effcff16853106771f7035 shorwall-1.3.7a.lrpIn other words, type "md5sum <whatever package you downloaded> - and compare the result with what you see above.
- -I'm embarrassed to report that 1.2.7 was also DOA -- maybe I'll skip the - .7 version in each sequence from now on.
- -Version 1.3.6
- --
- -- - - -
-If ADD_SNAT_ALIASES=Yes is specified in /etc/shorewall/shorewall.conf, - an error occurs when the firewall script attempts to -add an SNAT alias.
-- - -
- -The logunclean and dropunclean options - cause errors during startup when Shorewall is run with iptables - 1.2.7.
-These problems are fixed in - this correct firewall script which must be installed in - /var/lib/shorewall/ as described above. These problems are also - corrected in version 1.3.7.
- -Two-interface Samples 1.3.6 (file two-interfaces.tgz)
- -A line was inadvertently deleted from the "interfaces - file" -- this line should be added back in if the version that you - downloaded is missing it:
- -net eth0 detect routefilter,dhcp,norfc1918
- -If you downloaded two-interfaces-a.tgz then the above - line should already be in the file.
- -Version 1.3.5-1.3.5b
- -The new 'proxyarp' interface option doesn't work :-( - This is fixed in - this corrected firewall script which must be installed in - /var/lib/shorewall/ as described above.
- -Versions 1.3.4-1.3.5a
- -Prior to version 1.3.4, host file entries such as the - following were allowed:
- --- -adm eth0:1.2.4.5,eth0:5.6.7.8--- -That capability was lost in version 1.3.4 so that it is only - possible to include a single host specification on each line. - This problem is corrected by this - modified 1.3.5a firewall script. Install the script in /var/lib/pub/shorewall/firewall - as instructed above.
--- -This problem is corrected in version 1.3.5b.
-Version 1.3.5
- -REDIRECT rules are broken in this version. Install - - this corrected firewall script in /var/lib/pub/shorewall/firewall - as instructed above. This problem is corrected in version - 1.3.5a.
- -Version 1.3.n, n < 4
- -The "shorewall start" and "shorewall restart" commands - to not verify that the zones named in the /etc/shorewall/policy -file have been previously defined in the /etc/shorewall/zones -file. The "shorewall check" command does perform this verification -so it's a good idea to run that command after you have made configuration - changes.
- -Version 1.3.n, n < 3
- -If you have upgraded from Shorewall 1.2 and after - "Activating rules..." you see the message: "iptables: No chains/target/match - by that name" then you probably have an entry in /etc/shorewall/hosts - that specifies an interface that you didn't include in - /etc/shorewall/interfaces. To correct this problem, you - must add an entry to /etc/shorewall/interfaces. Shorewall 1.3.3 -and later versions produce a clearer error message in this -case.
- -Version 1.3.2
- -Until approximately 2130 GMT on 17 June 2002, the - download sites contained an incorrect version of the .lrp file. That - file can be identified by its size (56284 bytes). The correct -version has a size of 38126 bytes.
- --
- -- The code to detect a duplicate interface - entry in /etc/shorewall/interfaces contained a typo that prevented - it from working correctly.
-- "NAT_BEFORE_RULES=No" was broken; it behaved - just like "NAT_BEFORE_RULES=Yes".
- -Both problems are corrected in - this script which should be installed in /var/lib/shorewall - as described above.
- --
- -- - - -
- -The IANA have just announced the allocation of subnet - 221.0.0.0/8. This - updated rfc1918 file reflects that allocation.
-Version 1.3.1
- --
- -- TCP SYN packets may be double counted -when LIMIT:BURST is included in a CONTINUE or ACCEPT policy -(i.e., each packet is sent through the limit chain twice).
-- An unnecessary jump to the policy chain - is sometimes generated for a CONTINUE policy.
-- When an option is given for more than -one interface in /etc/shorewall/interfaces then depending - on the option, Shorewall may ignore all but the first -appearence of the option. For example:
-
-
- net eth0 dhcp
- loc eth1 dhcp
-
- Shorewall will ignore the 'dhcp' on eth1.- Update 17 June 2002 - The bug described - in the prior bullet affects the following options: dhcp, - dropunclean, logunclean, norfc1918, routefilter, multi, - filterping and noping. An additional bug has been found - that affects only the 'routestopped' option.
- -
-
- Users who downloaded the corrected script -prior to 1850 GMT today should download and install -the corrected script again to ensure that this second -problem is corrected.These problems are corrected in - this firewall script which should be installed in /etc/shorewall/firewall - as described above.
- -Version 1.3.0
- --
- -- Folks who downloaded 1.3.0 from the links - on the download page before 23:40 GMT, 29 May 2002 may - have downloaded 1.2.13 rather than 1.3.0. The "shorewall - version" command will tell you which version that you - have installed.
-- The documentation NAT.htm file uses non-existent - wallpaper and bullet graphic files. The - corrected version is here.
- -
-Upgrade Issues
- -The upgrade issues have moved to a separate page.
- +
-Problem with - iptables version 1.2.3
- -- -- - -There are a couple of serious bugs in iptables 1.2.3 that - prevent it from working with Shorewall. Regrettably, RedHat - released this buggy iptables in RedHat 7.2.
- - -I have built a - corrected 1.2.3 rpm which you can download here and I have -also built an -iptables-1.2.4 rpm which you can download here. If you are currently - running RedHat 7.1, you can install either of these RPMs - before you upgrade to RedHat 7.2.
+Problems in Version 1.4
-Update 11/9/2001: RedHat - has released an iptables-1.2.4 RPM of their own which you can -download from http://www.redhat.com/support/errata/RHSA-2001-144.html. - I have installed this RPM on my firewall and it works -fine.
- - -If you would like to patch iptables 1.2.3 yourself, - the patches are available for download. This patch - which corrects a problem with parsing of the --log-level specification - while this patch - corrects a problem in handling the TOS target.
- - -To install one of the above patches:
- - --
-- cd iptables-1.2.3/extensions
-- patch -p0 < the-patch-file
- - -Problems with kernels >= 2.4.18 - and RedHat iptables
- --+ + None. +Users who use RedHat iptables RPMs and who upgrade to kernel 2.4.18/19 - may experience the following:
- - -- -- - -# shorewall start-
Processing /etc/shorewall/shorewall.conf ...
Processing /etc/shorewall/params ...
Starting Shorewall...
Loading Modules...
Initializing...
Determining Zones...
Zones: net
Validating interfaces file...
Validating hosts file...
Determining Hosts in Zones...
Net Zone: eth0:0.0.0.0/0
iptables: libiptc/libip4tc.c:380: do_check: Assertion
`h->info.valid_hooks == (1 << 0 | 1 << 3)' failed.
Aborted (core dumped)
iptables: libiptc/libip4tc.c:380: do_check: Assertion
`h->info.valid_hooks == (1 << 0 | 1 << 3)' failed.
Aborted (core dumped)The RedHat iptables RPM is compiled with debugging enabled but the - user-space debugging code was not updated to reflect recent changes in - the Netfilter 'mangle' table. You can correct the problem by -installing - this iptables RPM. If you are already running a 1.2.5 version - of iptables, you will need to specify the --oldpackage option to - rpm (e.g., "iptables -Uvh --oldpackage iptables-1.2.5-1.i386.rpm").
-
+Upgrade Issues
+ +The upgrade issues have moved to a separate page.
+ +
+Problem with + iptables version 1.2.3
+ ++ ++ + +There are a couple of serious bugs in iptables 1.2.3 that + prevent it from working with Shorewall. Regrettably, RedHat + released this buggy iptables in RedHat 7.2.
+I have built a + corrected 1.2.3 rpm which you can download here and I have + also built an +iptables-1.2.4 rpm which you can download here. If you are currently + running RedHat 7.1, you can install either of these RPMs + before you upgrade to RedHat 7.2.
+ + +Update 11/9/2001: RedHat + has released an iptables-1.2.4 RPM of their own which you can +download from http://www.redhat.com/support/errata/RHSA-2001-144.html. + I have installed this RPM on my firewall and it works + fine.
+ + +If you would like to patch iptables 1.2.3 yourself, + the patches are available for download. This patch + which corrects a problem with parsing of the --log-level specification + while this patch + corrects a problem in handling the TOS target.
+ + +To install one of the above patches:
+ + ++
+- cd iptables-1.2.3/extensions
+- patch -p0 < the-patch-file
+ + +Problems with kernels >= 2.4.18 + and RedHat iptables
+ ++ ++ +Users who use RedHat iptables RPMs and who upgrade to kernel 2.4.18/19 + may experience the following:
+ + ++ ++ + +# shorewall start+
Processing /etc/shorewall/shorewall.conf ...
Processing /etc/shorewall/params ...
Starting Shorewall...
Loading Modules...
Initializing...
Determining Zones...
Zones: net
Validating interfaces file...
Validating hosts file...
Determining Hosts in Zones...
Net Zone: eth0:0.0.0.0/0
iptables: libiptc/libip4tc.c:380: do_check: Assertion
`h->info.valid_hooks == (1 << 0 | 1 << 3)' failed.
Aborted (core dumped)
iptables: libiptc/libip4tc.c:380: do_check: Assertion
`h->info.valid_hooks == (1 << 0 | 1 << 3)' failed.
Aborted (core dumped)The RedHat iptables RPM is compiled with debugging enabled but the + user-space debugging code was not updated to reflect recent changes in + the Netfilter 'mangle' table. You can correct the problem by + installing + this iptables RPM. If you are already running a 1.2.5 version + of iptables, you will need to specify the --oldpackage option to + rpm (e.g., "iptables -Uvh --oldpackage iptables-1.2.5-1.i386.rpm").
+Problems installing/upgrading - RPM on SuSE
- + RPM on SuSE +If you find that rpm complains about a conflict with kernel <= 2.2 yet you have a 2.4 kernel installed, simply use the "--nodeps" option to rpm.
- +Installing: rpm -ivh --nodeps <shorewall rpm>
- +Upgrading: rpm -Uvh --nodeps <shorewall rpm>
- +Problems with iptables version 1.2.7 and MULTIPORT=Yes
- +The iptables 1.2.7 release of iptables has made an incompatible change to the syntax used to specify multiport match rules; as a consequence, if you install iptables 1.2.7 you must be running Shorewall 1.3.7a or later or:
- +-
- +- set MULTIPORT=No in - /etc/shorewall/shorewall.conf; or
-- if you are running -Shorewall 1.3.6 you may install - set MULTIPORT=No +in /etc/shorewall/shorewall.conf; or
+- if you are running + Shorewall 1.3.6 you may install + this firewall script in /var/lib/shorewall/firewall - as described above.
- + as described above. +Problems with RH Kernel 2.4.18-10 and NAT
- /etc/shorewall/nat entries of the following form will result - in Shorewall being unable to start:
-
-
- + + /etc/shorewall/nat entries of the following form will result + in Shorewall being unable to start:
+
+#EXTERNAL INTERFACE INTERNAL ALL INTERFACES LOCAL- Error message is:
192.0.2.22 eth0 192.168.9.22 yes yes
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE
- + Error message is:
+Setting up NAT...- The solution is to put "no" in the LOCAL column. Kernel support - for LOCAL=yes has never worked properly and 2.4.18-10 has disabled it. - The 2.4.19 kernel contains corrected support under a new kernel configuraiton + The solution is to put "no" in the LOCAL column. Kernel support + for LOCAL=yes has never worked properly and 2.4.18-10 has disabled +it. The 2.4.19 kernel contains corrected support under a new kernel configuraiton option; see http://www.shorewall.net/Documentation.htm#NAT
iptables: Invalid argument
Terminated
- +Last updated 2/8/2003 - Tom Eastep
- +Copyright © 2001, 2002, 2003 Thomas M. Eastep.
-
-
-
-
-
-
-
-
-
+
diff --git a/Shorewall-docs/mailing_list.htm b/Shorewall-docs/mailing_list.htm index 8fd3276af..094d29e17 100644 --- a/Shorewall-docs/mailing_list.htm +++ b/Shorewall-docs/mailing_list.htm @@ -2,152 +2,152 @@ - + - + - + - +Shorewall Mailing Lists - + + - +- -
- -- ++ + +- + + -+ -
-
- - + +
-
- + ++ -Shorewall Mailing Lists
-+ - -
- +
+ -
- + +
+-
-
- Powered by Postfix
-
+ Powered by Postfix
+ + + - - + +Not getting List Mail? -- Check Here
- -If you experience problems with any of these lists, please - let me know
- + + +If you experience problems with any of these lists, please + let me know
+Not able to Post Mail to shorewall.net?
- -You can report such problems by sending mail to tom dot eastep + +
You can report such problems by sending mail to tom dot eastep at hp dot com.
- +A Word about SPAM Filters
- -Before subscribing please read my policy - about list traffic that bounces. Also please note that the mail server + +
Before subscribing please read my policy + about list traffic that bounces. Also please note that the mail server at shorewall.net checks incoming mail:
- + +
--
- +- against Spamassassin +
- against Spamassassin (including Vipul's Razor).
-
-- to ensure that the sender address is fully qualified.
-- to verify that the sender's domain has an A or MX record - in DNS.
-- to ensure that the host name in the HELO/EHLO command - is a valid fully-qualified DNS name that resolves.
- + +- to ensure that the sender address is fully qualified.
+- to verify that the sender's domain has an A or MX +record in DNS.
+- to ensure that the host name in the HELO/EHLO command + is a valid fully-qualified DNS name that resolves.
+Please post in plain text
- A growing number of MTAs serving list subscribers are rejecting -all HTML traffic. At least one MTA has gone so far as to blacklist shorewall.net - "for continuous abuse" because it has been my policy to allow HTML in list - posts!!
-
- I think that blocking all HTML is a Draconian way to control spam - and that the ultimate losers here are not the spammers but the list subscribers - whose MTAs are bouncing all shorewall.net mail. As one list subscriber - wrote to me privately "These e-mail admin's need to get a (explitive - deleted) life instead of trying to rid the planet of HTML based e-mail". - Nevertheless, to allow subscribers to receive list posts as must as possible, - I have now configured the list server at shorewall.net to strip all HTML - from outgoing posts. This means that HTML-only posts will be bounced by + A growing number of MTAs serving list subscribers are rejecting + all HTML traffic. At least one MTA has gone so far as to blacklist shorewall.net + "for continuous abuse" because it has been my policy to allow HTML in +list posts!!
+
+ I think that blocking all HTML is a Draconian way to control spam + and that the ultimate losers here are not the spammers but the list +subscribers whose MTAs are bouncing all shorewall.net mail. As one list +subscriber wrote to me privately "These e-mail admin's need to get a (explitive + deleted) life instead of trying to rid the planet of HTML based e-mail". + Nevertheless, to allow subscribers to receive list posts as must as possible, + I have now configured the list server at shorewall.net to strip all HTML + from outgoing posts. This means that HTML-only posts will be bounced by the list server.
- -Note: The list server limits posts to 120kb.
+
-Note: The list server limits posts to 120kb.
+
+Other Mail Delivery Problems
- If you find that you are missing an occasional list post, your e-mail - admin may be blocking mail whose Received: headers contain the names - of certain ISPs. Again, I believe that such policies hurt more than they - help but I'm not prepared to go so far as to start stripping Received: + If you find that you are missing an occasional list post, your e-mail + admin may be blocking mail whose Received: headers contain the +names of certain ISPs. Again, I believe that such policies hurt more than +they help but I'm not prepared to go so far as to start stripping Received: headers to circumvent those policies.
- +Mailing Lists Archive Search
- - -Please do not try to download the entire -Archive -- it is 75MB (and growing daily) and my slow DSL line simply won't -stand the traffic. If I catch you, you will be blacklisted.
- + +
-Please do not try to download the +entire Archive -- it is 75MB (and growing daily) and my slow DSL line simply +won't stand the traffic. If I catch you, you will be blacklisted.
+
+Shorewall CA Certificate
- If you want to trust X.509 certificates issued by Shoreline - Firewall (such as the one used on my web site), you may download and install my CA certificate - in your browser. If you don't wish to trust my certificates then -you can either use unencrypted access when subscribing to Shorewall -mailing lists or you can use secure access (SSL) and accept the server's + If you want to trust X.509 certificates issued by Shoreline + Firewall (such as the one used on my web site), you may download and install my CA certificate + in your browser. If you don't wish to trust my certificates then +you can either use unencrypted access when subscribing to Shorewall +mailing lists or you can use secure access (SSL) and accept the server's certificate when prompted by your browser.
- +Shorewall Users Mailing List
- -The Shorewall Users Mailing list provides a way for users - to get answers to questions and to report problems. Information -of general interest to the Shorewall user community is also posted + +
The Shorewall Users Mailing list provides a way for users + to get answers to questions and to report problems. Information +of general interest to the Shorewall user community is also posted to this list.
- -Before posting a problem report to this list, please see - the problem reporting + +
Before posting a problem report to this list, please see + the problem reporting guidelines.
- -To subscribe to the mailing list:
- -
--
- -- Insecure: http://lists.shorewall.net/mailman/listinfo/shorewall-users
-- SSL: https//lists.shorewall.net/mailman/listinfo/shorewall-users
- -To post to the list, post to shorewall-users@lists.shorewall.net.
- -The list archives are at http://lists.shorewall.net/pipermail/shorewall-users.
- -Note that prior to 1/1/2002, the mailing list was hosted -at Sourceforge. The archives from that -list may be found at www.geocrawler.com/lists/3/Sourceforge/9327/0/.
- -Shorewall Announce Mailing List
- -This list is for announcements of general interest to the - Shorewall community. To subscribe:
- - - -
--
- -- Insecure: http://lists.shorewall.net/mailman/listinfo/shorewall-announce
-- SSL: https//lists.shorewall.net/mailman/listinfo/shorewall-announce.
- -- -
- The list archives are at http://lists.shorewall.net/pipermail/shorewall-announce.Shorewall Development Mailing List
- -The Shorewall Development Mailing list provides a forum for - the exchange of ideas about the future of Shorewall and for coordinating - ongoing Shorewall Development.
- +To subscribe to the mailing list:
- +
-
+ +- Insecure: Insecure: http://lists.shorewall.net/mailman/listinfo/shorewall-users
+- SSL: https//lists.shorewall.net/mailman/listinfo/shorewall-users
+ +To post to the list, post to shorewall-users@lists.shorewall.net.
+ +The list archives are at http://lists.shorewall.net/pipermail/shorewall-users.
+ +Note that prior to 1/1/2002, the mailing list was hosted at +Sourceforge. The archives from that list +may be found at www.geocrawler.com/lists/3/Sourceforge/9327/0/.
+ +Shorewall Announce Mailing List
+ +This list is for announcements of general interest to the + Shorewall community. To subscribe:
+ + + +
++
+ +- Insecure: http://lists.shorewall.net/mailman/listinfo/shorewall-announce
+- SSL: https//lists.shorewall.net/mailman/listinfo/shorewall-announce.
+ ++ +
+ The list archives are at http://lists.shorewall.net/pipermail/shorewall-announce.Shorewall Development Mailing List
+ +The Shorewall Development Mailing list provides a forum for + the exchange of ideas about the future of Shorewall and for coordinating + ongoing Shorewall Development.
+ +To subscribe to the mailing list:
+ +
++
- +- Insecure: http://lists.shorewall.net/mailman/listinfo/shorewall-devel
-- SSL: SSL: https//lists.shorewall.net/mailman/listinfo/shorewall-devel.
- +To post to the list, post to shorewall-devel@lists.shorewall.net.
- +The list archives are at http://lists.shorewall.net/pipermail/shorewall-devel.
- -How to Unsubscribe from one of + +
How to Unsubscribe from one of the Mailing Lists
- -There seems to be near-universal confusion about unsubscribing - from Mailman-managed lists although Mailman 2.1 has attempted -to make this less confusing. To unsubscribe:
- + +There seems to be near-universal confusion about unsubscribing + from Mailman-managed lists although Mailman 2.1 has attempted to + make this less confusing. To unsubscribe:
+-
- -- - -
Follow the same link above that you used to subscribe +
- + +
-Follow the same link above that you used to subscribe to the list.
-- - -
-Down at the bottom of that page is the following text: - " To unsubscribe from <list name>, get a password - reminder, or change your subscription options enter your subscription - email address:". Enter your email address in the box and click - on the "Unsubscribe or edit options" button.
-- - -
+There will now be a box where you can enter your password - and click on "Unsubscribe"; if you have forgotten your password, - there is another button that will cause your password to be emailed +
- + +
+Down at the bottom of that page is the following text: + " To unsubscribe from <list name>, get a password + reminder, or change your subscription options enter your subscription + email address:". Enter your email address in the box and +click on the "Unsubscribe or edit options" button.
+- + +
- + +There will now be a box where you can enter your password + and click on "Unsubscribe"; if you have forgotten your password, + there is another button that will cause your password to be emailed to you.
-
+ +
Frustrated by having to Rebuild Mailman to use it with Postfix?
- + - -Last updated 2/3/2003 - Last updated 2/18/2003 - Tom Eastep
- -Copyright © -2001, 2002, 2003 Thomas M. Eastep.
+ +
-Copyright +© 2001, 2002, 2003 Thomas M. Eastep.
+
+
diff --git a/Shorewall-docs/myfiles.htm b/Shorewall-docs/myfiles.htm deleted file mode 100644 index e43a34778..000000000 --- a/Shorewall-docs/myfiles.htm +++ /dev/null @@ -1,190 +0,0 @@ - - - - - -My Shorewall Configuration - - - - - - - - - -- -
- -- - - -- - -About My Network
-- -My Current Network
- --- -Warning: I -use a combination of Static NAT and Proxy ARP, neither of which are relevant -to a simple configuration with a single public IP address. -If you have just a single public IP address, most of what you see here won't -apply to your setup so beware of copying parts of this configuration and expecting -them to work for you. What you copy may or may not work in your setup.
- -
-I have DSL service and have 5 static IP addresses (206.124.146.176-180). - My DSL "modem" (Fujitsu Speedport) - is connected to eth0. I have a local network connected to eth2 (subnet - 192.168.1.0/24) and a DMZ connected to eth1 (192.168.2.0/24).
- -I use:
- -
--
- -- Static NAT for ursa (my XP System) - Internal address 192.168.1.5 - and external address 206.124.146.178.
-- Proxy ARP for wookie (my Linux System). This system has two - IP addresses: 192.168.1.3/24 and 206.124.146.179/24.
-- SNAT through the primary gateway address (206.124.146.176) - for my Wife's system (tarry) and the Wireless Access Point (wap)
- -The firewall runs on a 128MB PII/233 with RH7.2 and Kernel 2.4.20-pre6.
- -Wookie runs Samba and acts as the a WINS server. Wookie is in its - own 'whitelist' zone called 'me'.
- -My laptop (eastept1) is connected to eth3 using a cross-over cable. - It runs its own Sygate firewall -software and is managed by Proxy ARP. It connects to the local network -through the PopTop server running on my firewall.
- -The single system in the DMZ (address 206.124.146.177) runs postfix, - Courier IMAP (imaps and pop3), DNS, a Web server (Apache) and an FTP -server (Pure-ftpd). The system also runs fetchmail to fetch our email -from our old and current ISPs. That server is managed through Proxy ARP.
- -The firewall system itself runs a DHCP server that serves the local - network.
- -All administration and publishing is done using ssh/scp.
- -I run an SNMP server on my firewall to serve MRTG running - in the DMZ.
- -- -
-
- -
The ethernet interface in the Server is configured - with IP address 206.124.146.177, netmask - 255.255.255.0. The server's default gateway is - 206.124.146.254 (Router at my ISP. This is the same - default gateway used by the firewall itself). On the firewall, - Shorewall automatically adds a host route to - 206.124.146.177 through eth1 (192.168.2.1) because - of the entry in /etc/shorewall/proxyarp (see - below).
- -A similar setup is used on eth3 (192.168.3.1) which - interfaces to my laptop (206.124.146.180).
- -
-Ursa (192.168.1.5 AKA 206.124.146.178) runs a PPTP server for Road Warrior - access.
- - -
-Shorewall.conf
- -SUBSYSLOCK=/var/lock/subsys/shorewall- -
STATEDIR=/var/state/shorewall
LOGRATE=
LOGBURST=
ADD_IP_ALIASES="Yes"
CLAMPMSS=Yes
MULTIPORT=YesZones File:
- -#ZONE DISPLAY COMMENTS- -
net Internet Internet
me Eastep My Workstation
loc Local Local networks
dmz DMZ Demilitarized zone
tx Texas Peer Network in Dallas Texas
#LAST LINE - ADD YOUR ENTRIES ABOVE THIS ONE - DO NOT REMOVEInterfaces File:
- --- -This is set up so that I can start the firewall before bringing up -my Ethernet interfaces.
-#ZONE INTERFACE BROADCAST OPTIONS- -
net eth0 206.124.146.255 routefilter,norfc1918,blacklist,filterping
loc eth2 192.168.1.255 dhcp,filterping,maclist
dmz eth1 206.124.146.255 filterping
net eth3 206.124.146.255 filterping,blacklist
- texas - filterping
loc ppp+ - filterping
#LAST LINE -- ADD YOUR ENTRIES BEFORE THIS ONE -- DO NOT REMOVEHosts File:
- -#ZONE HOST(S) OPTIONS- -
me eth2:192.168.1.3,eth2:206.124.146.179
tx texas:192.168.9.0/24
#LAST LINE -- ADD YOUR ENTRIES ABOVE -- DO NOT REMOVERoutestopped File:
- -#INTERFACE HOST(S)- -
eth1 206.124.146.177
eth2 -
eth3 206.124.146.180Common File:
- -. /etc/shorewall/common.def- -
run_iptables -A common -p udp --sport 53 -mstate --state NEW -j DROPPolicy File:
- -- #SOURCE DEST POLICY LOG LEVEL LIMIT:BURST - me all ACCEPT - tx me ACCEPT #Give Texas access to my personal system - all me CONTINUE #WARNING: You must be running Shorewall 1.3.1 or later for- -
# this policy to work as expected!!!
loc loc ACCEPT
loc net ACCEPT
$FW loc ACCEPT
$FW tx ACCEPT
loc tx ACCEPT
loc fw REJECT
net net ACCEPT
net all DROP info 10/sec:40
all all REJECT info
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOTEMasq File:
- -- -- -Although most of our internal systems use static NAT, my wife's system - (192.168.1.4) uses IP Masquerading (actually SNAT) as do visitors with - laptops. Also, I masquerade wookie to the peer subnet in Texas.
-#INTERFACE SUBNET ADDRESS- -
eth0 192.168.1.0/24 206.124.146.176
texas 206.124.146.179 192.168.1.254
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVENAT File:
- -#EXTERNAL INTERFACE INTERNAL ALL LOCAL- -
206.124.146.178 eth0 192.168.1.5 No No
206.124.146.179 eth0 192.168.1.3 No No
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVEProxy ARP File:
- -#ADDRESS INTERFACE EXTERNAL HAVEROUTE- -
206.124.146.177 eth1 eth0 No
206.124.146.180 eth3 eth0 No#LAST LINE -- ADD YOUR ENTRIES BEFORE THIS ONE -- DO NOT REMOVETunnels File (Shell variable TEXAS set in /etc/shorewall/params):
- -#TYPE ZONE GATEWAY- -
gre net $TEXAS
#LAST LINE -- DO NOT REMOVERules File (The shell variables - are set in /etc/shorewall/params):
- -#ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL- -
# PORT(S) PORT(S) PORT(S) DEST
#
# Local Network to Internet - Reject attempts by Trojans to call home
#
REJECT:info loc net tcp 6667
#
# Local Network to Firewall
#
ACCEPT loc fw tcp ssh
ACCEPT loc fw tcp time
#
# Local Network to DMZ
#
ACCEPT loc dmz udp domain
ACCEPT loc dmz tcp smtp
ACCEPT loc dmz tcp domain
ACCEPT loc dmz tcp ssh
ACCEPT loc dmz tcp auth
ACCEPT loc dmz tcp imap
ACCEPT loc dmz tcp https
ACCEPT loc dmz tcp imaps
ACCEPT loc dmz tcp cvspserver
ACCEPT loc dmz tcp www
ACCEPT loc dmz tcp ftp
ACCEPT loc dmz tcp pop3
ACCEPT loc dmz icmp echo-request
#
# Internet to DMZ
#
ACCEPT net dmz tcp www
ACCEPT net dmz tcp smtp
ACCEPT net dmz tcp ftp
ACCEPT net dmz tcp auth
ACCEPT net dmz tcp https
ACCEPT net dmz tcp imaps
ACCEPT net dmz tcp domain
ACCEPT net dmz tcp cvspserver
ACCEPT net dmz udp domain
ACCEPT net dmz icmp echo-request
ACCEPT net:$MIRRORS dmz tcp rsync
#
# Net to Me (ICQ chat and file transfers)
#
ACCEPT net me tcp 4000:4100
#
# Net to Local
#
ACCEPT net loc tcp auth
REJECT net loc tcp www
ACCEPT net loc:192.168.1.5 tcp 1723
ACCEPT net loc:192.168.1.5 gre
#
# DMZ to Internet
#
ACCEPT dmz net icmp echo-request
ACCEPT dmz net tcp smtp
ACCEPT dmz net tcp auth
ACCEPT dmz net tcp domain
ACCEPT dmz net tcp www
ACCEPT dmz net tcp https
ACCEPT dmz net tcp whois
ACCEPT dmz net tcp echo
ACCEPT dmz net udp domain
ACCEPT dmz net:$NTPSERVERS udp ntp
ACCEPT dmz net:$POPSERVERS tcp pop3
#
# The following compensates for a bug, either in some FTP clients or in the
# Netfilter connection tracking code that occasionally denies active mode
# FTP clients
#
ACCEPT:info dmz net tcp 1024: 20
#
# DMZ to Firewall -- snmp
#
ACCEPT dmz fw tcp snmp
ACCEPT dmz fw udp snmp
#
# DMZ to Local Network
#
ACCEPT dmz loc tcp smtp
ACCEPT dmz loc tcp auth
ACCEPT dmz loc icmp echo-request
# Internet to Firewall
#
REJECT net fw tcp www
#
# Firewall to Internet
#
ACCEPT fw net:$NTPSERVERS udp ntp
ACCEPT fw net udp domain
ACCEPT fw net tcp domain
ACCEPT fw net tcp www
ACCEPT fw net tcp https
ACCEPT fw net tcp ssh
ACCEPT fw net tcp whois
ACCEPT fw net icmp echo-request
#
# Firewall to DMZ
#
ACCEPT fw dmz tcp www
ACCEPT fw dmz tcp ftp
ACCEPT fw dmz tcp ssh
ACCEPT fw dmz tcp smtp
ACCEPT fw dmz udp domain
#
# Let Texas Ping
#
ACCEPT tx fw icmp echo-request
ACCEPT tx loc icmp echo-request
#LAST LINE -- ADD YOUR ENTRIES BEFORE THIS ONE -- DO NOT REMOVELast updated 1/12/2003 - - Tom Eastep -
- Copyright © -2001, 2002, 2003 Thomas M. Eastep.
-
-
- - diff --git a/Shorewall-docs/ping.html b/Shorewall-docs/ping.html index fdf4b1126..7a392c7bb 100644 --- a/Shorewall-docs/ping.html +++ b/Shorewall-docs/ping.html @@ -2,147 +2,184 @@ICMP Echo-request (Ping) - + - + - +- -
-- ++ + - - + + + +- ICMP Echo-request (Ping)
-
- Shorewall 'Ping' management has evolved over time with the latest change -coming in Shorewall version 1.3.14. In that version, a new option (OLD_PING_HANDLING) -was added to /etc/shorewall/shorewall.conf. The value of that option determines -the overall handling of ICMP echo requests (pings).
- -Shorewall Versions >= 1.3.14 with OLD_PING_HANDLING=No in /etc/shorewall/shorewall.conf
- In 1.3.14, Ping handling was put under control of the rules and policies -just like any other connection request. In order to accept ping requests from -zone z1 to zone z2 where the policy for z1 to z2 is not ACCEPT, you need -a rule in /etc/shoreall/rules of the form:
- +
+ Shorewall 'Ping' management has evolved over time with the latest change + coming in Shorewall version 1.4.0.
+ +Shorewall Versions >= 1.4.0
+ In order to accept ping requests from zone z1 to zone z2 where the policy +for z1 to z2 is not ACCEPT, you need a rule in /etc/shoreall/rules of the +form:
+ACCEPT z1 z2 - icmp 8- Example:
-
-
- To permit ping from the local zone to the firewall:
- + icmp 8
+
ACCEPT loc fw -icmp 8- If you would like to accept 'ping' by default even when the relevant -policy is DROP or REJECT, create /etc/shorewall/icmpdef if it doesn't -already exist and in that file place the following command:
-
+ icmp 8+ If you would like to accept 'ping' by default even when the relevant + policy is DROP or REJECT, create /etc/shorewall/icmpdef if it doesn't + already exist and in that file place the following command:
+
- With that rule in place, if you want to ignore 'ping' from z1 to z2 then -you need a rule of the form:run_iptables -A icmpdef -p icmp --icmp-type 8 -j ACCEPT-
DROP z1 z2 - icmp 8- Example:
-
DROP net fw -icmp 8-
+ icmp 8
- -
Updated 1/21/2003 - Tom Eastep -
+ACCEPT z1 z2 + icmp 8+ Example:
+
ACCEPT loc fw + icmp 8+ If you would like to accept 'ping' by default even when the relevant + policy is DROP or REJECT, create /etc/shorewall/icmpdef if it doesn't + already exist and in that file place the following command:
+
++ With that rule in place, if you want to ignore 'ping' from z1 to z2 then + you need a rule of the form:run_iptables -A icmpdef -p icmp --icmp-type 8 -j ACCEPT+
DROP z1 z2 + icmp 8+ Example:
+
DROP net fw + icmp 8+ +
+
+ +
Updated 2/14/2003 - Tom Eastep +
+Copyright © 2001, 2002, 2003 Thomas M. Eastep.
++ |
@@ -39,15 +40,16 @@
-
+
+
+ Shorewall
+1.4 - "iptables made
+ easy"
@@ -56,42 +58,44 @@
-
+
+
|
+
+
+
+ |
@@ -100,7 +104,8 @@
-
+
+
What is it?@@ -112,7 +117,8 @@ - + +The Shoreline Firewall, more commonly known as "Shorewall", is a Netfilter (iptables) based firewall that can be used on a dedicated firewall system, a multi-function @@ -127,28 +133,30 @@ firewall that can be used on a dedicated firewall system, a multi-functio - + + This program is free software; you can redistribute it and/or modify
- it under the terms of
- Version 2 of
-the GNU General Public License as published by the Free Software
- Foundation. Copyright 2001, 2002, 2003 Thomas M. Eastep @@ -171,28 +180,31 @@ with this program; if not, write to the Free Software - + + + Congratulations to Jacques and Eric on the recent release of
-Bering 1.0 Final!!! + - + + + + + + + This is a mirror of the main Shorewall web site at SourceForge (http://shorewall.sf.net)@@ -207,7 +219,8 @@ Bering 1.0 Final!!!- + + News@@ -219,7 +232,7 @@ Bering 1.0 Final!!!- + @@ -228,116 +241,111 @@ Bering 1.0 Final!!! - - 2/8/2003 - Shoreawll 1.3.14 New features include - -
- - 2/5/2003 - Shorewall Support included in Webmin 1.060
- - - + + 3/14/2003 - Shorewall 1.4.0 + Function from 1.3 that has been omitted from this version include: + +
+ +
- + + Donations- |
- + + | M | -
+ |
@@ -391,12 +404,12 @@ on subnetworks that you don't wish to masquerade. - + + @@ -406,30 +419,33 @@ on subnetworks that you don't wish to masquerade. - + + Shorewall is free but if you try it and find it useful, please consider making a donation - to Starlight Children's Foundation. Thanks! - |
+
-
Updated 2/7/2003 - Tom Eastep + + +
Updated 2/18/2003 - Tom Eastep
-
+
- + |
+
Tom Eastep- |
-
-
Tarry & Tom -- August 2002
-
-
I am currently a member of the design team for the next-generation - operating system from the NonStop Enterprise Division of HP.
- -I became interested in Internet Security when I established a home office - in 1999 and had DSL service installed in our home. I investigated - ipchains and developed the scripts which are now collectively known as - Seattle Firewall. Expanding - on what I learned from Seattle Firewall, I then designed and wrote - Shorewall.
- -I telework from our home in Shoreline, - Washington where I live with my wife Tarry.
- -Our current home network consists of:
+For more about our network see my Shorewall Configuration.
- + +I am currently a member of the design team for the next-generation + operating system from the NonStop Enterprise Division of HP.
+ +I became interested in Internet Security when I established a home office + in 1999 and had DSL service installed in our home. I investigated + ipchains and developed the scripts which are now collectively known +as Seattle Firewall. +Expanding on what I learned from Seattle Firewall, I then designed +and wrote Shorewall.
+ +I telework from our home in Shoreline, + Washington where I live with my wife Tarry.
+ +Our current home network consists of:
+ +All of our other systems are made by Compaq (part of the new HP).. All of our Tulip NICs are Netgear FA310TXs.
- + - - + +Last updated 2/18/2003 - Tom Eastep
- Copyright © 2001, 2002, 2003 Thomas -M. Eastep.- + |
+
Extension Scripts- |
+
-
Extension scripts are user-provided scripts that are invoked at various -points during firewall start, restart, stop and clear. The scripts are -placed in /etc/shorewall and are processed using the Bourne shell "source" + +
Extension scripts are user-provided scripts that are invoked at various +points during firewall start, restart, stop and clear. The scripts are +placed in /etc/shorewall and are processed using the Bourne shell "source" mechanism. The following scripts can be supplied:
- +If your version of Shorewall doesn't have the file that you want + +
If your version of Shorewall doesn't have the file that you want to use from the above list, you can simply create the file yourself.
-You can also supply a script with the same name as any of the filter - chains in the firewall and the script will be invoked after the /etc/shorewall/rules - file has been processed but before the /etc/shorewall/policy file has been - processed.
+ +You can also supply a script with the same name as any of the filter + chains in the firewall and the script will be invoked after the /etc/shorewall/rules + file has been processed but before the /etc/shorewall/policy file has +been processed.
- -The /etc/shorewall/common file receives special treatment. If this file -is present, the rules that it defines will totally replace the default -rules in the common chain. These default rules are contained in the -file /etc/shorewall/common.def which may be used as a starting point + +
The /etc/shorewall/common file receives special treatment. If this file +is present, the rules that it defines will totally replace the default +rules in the common chain. These default rules are contained in the +file /etc/shorewall/common.def which may be used as a starting point for making your own customized file.
- -Rather than running iptables directly, you should run it using the - function run_iptables. Similarly, rather than running "ip" directly, - you should use run_ip. These functions accept the same arguments as the - underlying command but cause the firewall to be stopped if an error occurs + +
Rather than running iptables directly, you should run it using the + function run_iptables. Similarly, rather than running "ip" directly, +you should use run_ip. These functions accept the same arguments as the + underlying command but cause the firewall to be stopped if an error occurs during processing of the command.
- -If you decide to create /etc/shorewall/common it is a good idea to -use the following technique
+ +If you decide to create /etc/shorewall/common it is a good idea to use +the following technique
- +/etc/shorewall/common:
- -- + ++ ++- -. /etc/shorewall/common.def-
<add your rules here>If you need to supercede a rule in the released common.def file, you can -add the superceding rule before the '.' command. Using this technique allows - you to add new rules while still getting the benefit of the latest common.def +
If you need to supercede a rule in the released common.def file, you can +add the superceding rule before the '.' command. Using this technique allows + you to add new rules while still getting the benefit of the latest common.def file.
- -Remember that /etc/shorewall/common defines rules that are only applied -if the applicable policy is DROP or REJECT. These rules are NOT applied + +
Remember that /etc/shorewall/common defines rules that are only applied +if the applicable policy is DROP or REJECT. These rules are NOT applied if the policy is ACCEPT or CONTINUE.
- -If you set ALLOWRELATED=No in shorewall.conf, then most ICMP packets will -be rejected by the firewall. It is recommended with this setting that you -create the file /etc/shorewall/icmpdef and in it place the following commands:
- - - - -run_iptables -A icmpdef -p ICMP --icmp-type echo-reply -j ACCEPT- - -
run_iptables -A icmpdef -p ICMP --icmp-type source-quench -j ACCEPT
run_iptables -A icmpdef -p ICMP --icmp-type destination-unreachable -j ACCEPT
run_iptables -A icmpdef -p ICMP --icmp-type time-exceeded -j ACCEPT
run_iptables -A icmpdef -p ICMP --icmp-type parameter-problem -j ACCEPT
Last updated 12/22/2002 - Last updated 2/18/2003 - Tom Eastep
- -Copyright 2002 Thomas -M. Eastep
-Copyright 2002, 2003 +Thomas M. Eastep
++ |
-
- Shorewall QuickStart Guides
- (HOWTO's)
- |
-
With thanks to Richard who reminded me once again that we
-must all first walk before we can run.
- The French Translations are courtesy of Patrice Vetsel
-
With thanks to Richard who reminded me once again that
+we must all first walk before we can run.
+ The French Translations are courtesy of Patrice Vetsel
+
These guides provide step-by-step instructions for configuring Shorewall - in common firewall setups.
- + +These guides provide step-by-step instructions for configuring Shorewall + in common firewall setups.
+The following guides are for users who have a single public IP address:
- +The above guides are designed to get your first firewall up and running - quickly in the three most common Shorewall configurations.
- -The Shorewall Setup Guide outlines - the steps necessary to set up a firewall where there are multiple - public IP addresses involved or if you want to learn more about Shorewall - than is explained in the single-address guides above.
- + +The above guides are designed to get your first firewall up and running + quickly in the three most common Shorewall configurations.
+ +The Shorewall Setup Guide outlines + the steps necessary to set up a firewall where there are multiple + public IP addresses involved or if you want to learn more about +Shorewall than is explained in the single-address guides above.
+The following documentation covers a variety of topics and supplements - the QuickStart Guides - described above. Please review the appropriate guide before trying - to use this documentation directly.
- -The following documentation covers a variety of topics and supplements + the QuickStart Guides + described above. Please review the appropriate guide before trying + to use this documentation directly.
+ +If you use one of these guides and have a suggestion for improvement please let me know.
- +Last modified 2/4/2003 - Tom Eastep
- -Copyright 2002, 2003 Thomas M. + + +
+1.0 Introduction
- 2.0 Shorewall Concepts
- 3.0 Network Interfaces
- 4.0 Addressing, Subnets and Routing
+ 2.0 Shorewall Concepts
+ 3.0 Network Interfaces
+ 4.0 Addressing, Subnets and Routing + +- - - -4.1 IP Addresses
-
- 4.2 Subnets
- 4.3 Routing
- 4.4 Address Resolution Protocol
- 4.5 RFC 1918- - -+-- + + + +5.2.1 SNAT
+ 4.2 Subnets
- 5.2.2 DNAT
- 5.2.3 Proxy ARP
- 5.2.4 Static NAT
+ 4.3 Routing
+ 4.4 Address Resolution Protocol
+ 4.5 RFC 1918+ + +- + 5.4 Odds and Ends +++ -5.2.1 SNAT
+
+ 5.2.2 DNAT
+ 5.2.3 Proxy ARP
+ 5.2.4 Static NAT6.0 DNS
- + 7.0 Starting and Stopping the Firewall +
- 7.0 Starting and Stopping the Firewall1.0 Introduction
- +This guide is intended for users who are setting up Shorewall in an environment - where a set of public IP addresses must be managed or who want to know -more about Shorewall than is contained in the single-address guides. Because - the range of possible applications is so broad, the Guide will give you - general guidelines and will point you to other resources as necessary.
- + the range of possible applications is so broad, the Guide will give you + general guidelines and will point you to other resources as necessary. +- + If you run LEAF Bering, your Shorewall configuration is NOT what + I release -- I suggest that you consider installing a stock Shorewall lrp + from the shorewall.net site before you proceed. +
- If you run LEAF Bering, your Shorewall configuration is NOT what -I release -- I suggest that you consider installing a stock Shorewall lrp -from the shorewall.net site before you proceed.
This guide assumes that you have the iproute/iproute2 package installed - (on RedHat, the package is called iproute). You can tell -if this package is installed by the presence of an ip program on -your firewall system. As root, you can use the 'which' command to check -for this program:
- + (on RedHat, the package is called iproute). You can tell + if this package is installed by the presence of an ip program on + your firewall system. As root, you can use the 'which' command to check + for this program: +[root@gateway root]# which ip- +
/sbin/ip
[root@gateway root]#I recommend that you first read through the guide to familiarize yourself - with what's involved then go back through it again making your configuration - changes. Points at which configuration changes are recommended are flagged - with
- + with what's involved then go back through it again making your configuration + changes. Points at which configuration changes are recommended are flagged + with- .
+ . +
- + If you edit your configuration files on a Windows system, you +must save them as Unix files if your editor supports that option or you +must run them through dos2unix before trying to use them with Shorewall. +Similarly, if you copy a configuration file from your Windows hard drive +to a floppy disk, you must run dos2unix against the copy before using +it with Shorewall. +
- If you edit your configuration files on a Windows system, you must - save them as Unix files if your editor supports that option or you must -run them through dos2unix before trying to use them with Shorewall. Similarly, - if you copy a configuration file from your Windows hard drive to a floppy - disk, you must run dos2unix against the copy before using it with Shorewall.
-
- +- Windows Version - of dos2unix
-- Linux - Version of dos2unix
- +- Windows Version + of dos2unix
+- Linux + Version of dos2unix
+2.0 Shorewall Concepts
- +The configuration files for Shorewall are contained in the directory /etc/shorewall -- for most setups, you will only need to deal with a few of these as described in this guide. Skeleton files are created during the Shorewall Installation Process.
- +As each file is introduced, I suggest that you look through the actual - file on your system -- each file contains detailed configuration instructions - and some contain default entries.
- + file on your system -- each file contains detailed configuration instructions + and some contain default entries. +Shorewall views the network where it is running as being composed of a - set of zones. In the default installation, the following zone names - are used:
- + set of zones. In the default installation, the following zone +names are used: +- -
- +- -Name -Description -- -net -The Internet -- -loc -Your Local Network -- - - + +dmz -Demilitarized Zone -+ +Name +Description ++ +net +The Internet ++ +loc +Your Local Network ++ + +dmz +Demilitarized Zone +Zones are defined in the /etc/shorewall/zones - file.
- + file. +Shorewall also recognizes the firewall system as its own zone - by default, - the firewall itself is known as fw but that may be changed in the - /etc/shorewall/shorewall.conf file. - In this guide, the default name (fw) will be used.
- + the firewall itself is known as fw but that may be changed in +the /etc/shorewall/shorewall.conf +file. In this guide, the default name (fw) will be used. +With the exception of fw, Shorewall attaches absolutely no meaning - to zone names. Zones are entirely what YOU make of them. That means that - you should not expect Shorewall to do something special "because this + to zone names. Zones are entirely what YOU make of them. That means that + you should not expect Shorewall to do something special "because this is the internet zone" or "because that is the DMZ".
- +- + Edit the /etc/shorewall/zones file and make any changes necessary. +
- Edit the /etc/shorewall/zones file and make any changes necessary.
Rules about what traffic to allow and what traffic to deny are expressed - in terms of zones.
- + in terms of zones. +-
- +- You express your default policy for connections from one zone -to another zone in the /etc/shorewall/policy - file.
-- You define exceptions to those default policies in the You express your default policy for connections from one zone + to another zone in the /etc/shorewall/policy + file.
+- You define exceptions to those default policies in the /etc/shorewall/rules file.
- +Shorewall is built on top of the Netfilter - kernel facility. Netfilter implements a connection - tracking function that allows what is often referred to as stateful - inspection of packets. This stateful property allows firewall rules - to be defined in terms of connections rather than in terms of + tracking function that allows what is often referred to as stateful + inspection of packets. This stateful property allows firewall rules + to be defined in terms of connections rather than in terms of packets. With Shorewall, you:
- +-
- +- Identify the source zone.
-- Identify the destination zone.
-- If the POLICY from the client's zone to the server's zone - is what you want for this client/server pair, you need do nothing -further.
-- If the POLICY is not what you want, then you must add -a rule. That rule is expressed in terms of the client's zone and +
- Identify the source zone.
+- Identify the destination zone.
+- If the POLICY from the client's zone to the server's +zone is what you want for this client/server pair, you need do nothing + further.
+- If the POLICY is not what you want, then you must add + a rule. That rule is expressed in terms of the client's zone and the server's zone.
- +Just because connections of a particular type are allowed from zone A to the firewall and are also allowed from the firewall to zone B DOES NOT mean that these connections are allowed - from zone A to zone B. It rather means that you can have - a proxy running on the firewall that accepts a connection from zone A -and then establishes its own separate connection from the firewall to -zone B.
- + from zone A to zone B. It rather means that you can +have a proxy running on the firewall that accepts a connection from +zone A and then establishes its own separate connection from the firewall +to zone B. +For each connection request entering the firewall, the request is first - checked against the /etc/shorewall/rules file. If no rule in that file -matches the connection request then the first policy in /etc/shorewall/policy -that matches the request is applied. If that policy is REJECT or DROP + checked against the /etc/shorewall/rules file. If no rule in that file + matches the connection request then the first policy in /etc/shorewall/policy + that matches the request is applied. If that policy is REJECT or DROP the request is first checked against the rules in /etc/shorewall/common.def.
- +The default /etc/shorewall/policy file has the following policies:
- --- -- -
-- -Source Zone -Destination Zone -Policy -Log Level -Limit:Burst -- -loc -net -ACCEPT -- - - -net -all -DROP -info -- - - - -all -all -REJECT -info -- The above policy will:
- --
- -- allow all connection requests from your local network to the internet
-- drop (ignore) all connection requests from the internet to your - firewall or local network and log a message at the info level -(here is a description of log levels).
-- reject all other connection requests and log a message at the - info level. When a request is rejected, the firewall will -return an RST (if the protocol is TCP) or an ICMP port-unreachable packet -for other protocols.
- -- -
- At this point, edit your /etc/shorewall/policy and make any changes - that you wish.
3.0 Network Interfaces
- -For the remainder of this guide, we'll refer to the following - diagram. While it may not look like your own network, it can be used to - illustrate the important aspects of Shorewall configuration.
- -In this diagram:
- --
- -- The DMZ Zone consists of systems DMZ 1 and DMZ 2. A DMZ is used - to isolate your internet-accessible servers from your local systems so -that if one of those servers is compromised, you still have the firewall -between the compromised system and your local systems.
-- The Local Zone consists of systems Local 1, Local 2 and Local -3.
-- All systems from the ISP outward comprise the Internet Zone.
- -- -
-
The simplest way to define zones is to simply associate the - zone name (previously defined in /etc/shorewall/zones) with a network -interface. This is done in the /etc/shorewall/interfaces - file.
- -The firewall illustrated above has three network interfaces. - Where Internet connectivity is through a cable or DSL "Modem", the External - Interface will be the Ethernet adapter that is connected to that "Modem" - (e.g., eth0) unless you connect via Point-to-Point - Protocol over Ethernet (PPPoE) or Point-to-Point - Tunneling Protocol (PPTP) in which case the External -Interface will be a ppp interface (e.g., ppp0). If you connect -via a regular modem, your External Interface will also be ppp0. -If you connect using ISDN, you external interface will be ippp0.
- -- -
- If your external interface is ppp0 or ippp0 then you - will want to set CLAMPMSS=yes in /etc/shorewall/shorewall.conf.
Your Local Interface will be an Ethernet adapter (eth0, - eth1 or eth2) and will be connected to a hub or switch. Your local computers - will be connected to the same switch (note: If you have only a single -local system, you can connect the firewall directly to the computer using -a cross-over cable).
- -Your DMZ Interface will also be an Ethernet adapter - (eth0, eth1 or eth2) and will be connected to a hub or switch. Your DMZ - computers will be connected to the same switch (note: If you have only -a single DMZ system, you can connect the firewall directly to the computer - using a cross-over cable).
- -- -
- Do not connect more than one interface to the same hub or switch - (even for testing). It won't work the way that you expect it to and you - will end up confused and believing that Linux networking doesn't work at -all.
For the remainder of this Guide, we will assume that:
- --
- -- -
-The external interface is eth0.
-- -
-The Local interface is eth1.
-- -
- -The DMZ interface is eth2.
-The Shorewall default configuration does not define the contents - of any zone. To define the above configuration using the /etc/shorewall/interfaces - file, that file would might contain:
- --- -- -
-- -Zone -Interface -Broadcast -Options -- -net -eth0 -detect -norfc1918 -- -loc -eth1 -detect -- - - - -dmz -eth2 -detect -- - -
- Edit the /etc/shorewall/interfaces file and define the network interfaces - on your firewall and associate each interface with a zone. If you have -a zone that is interfaced through more than one interface, simply include - one entry for each interface and repeat the zone name as many times as -necessary.
Example:
- --- -- -
-- -Zone -Interface -Broadcast -Options -- -net -eth0 -detect -norfc1918 -- -loc -eth1 -detect -- - - - -loc -eth2 -detect -dhcp --- -When you have more than one interface to a zone, you will - usually want a policy that permits intra-zone traffic:
--- + ++ +--
+ Source Zone Destination Zone Policy @@ -427,80 +210,301 @@ necessary.- - + loc -loc +net ACCEPT + +net +all +DROP +info ++ + + +all +all +REJECT +info ++ The above policy will:
+ ++
+ +- allow all connection requests from your local network to the +internet
+- drop (ignore) all connection requests from the internet to your + firewall or local network and log a message at the info level + (here is a description of log levels).
+- reject all other connection requests and log a message at the + info level. When a request is rejected, the firewall will + return an RST (if the protocol is TCP) or an ICMP port-unreachable +packet for other protocols.
+ ++ +
+ At this point, edit your /etc/shorewall/policy and make any changes + that you wish.
3.0 Network Interfaces
+ +For the remainder of this guide, we'll refer to the following + diagram. While it may not look like your own network, it can be used +to illustrate the important aspects of Shorewall configuration.
+ +In this diagram:
+ ++
+ +- The DMZ Zone consists of systems DMZ 1 and DMZ 2. A DMZ is used + to isolate your internet-accessible servers from your local systems so + that if one of those servers is compromised, you still have the firewall + between the compromised system and your local systems.
+- The Local Zone consists of systems Local 1, Local 2 and Local + 3.
+- All systems from the ISP outward comprise the Internet Zone. +
+ ++ +
+
The simplest way to define zones is to simply associate the + zone name (previously defined in /etc/shorewall/zones) with a network +interface. This is done in the /etc/shorewall/interfaces + file.
+ +The firewall illustrated above has three network interfaces. + Where Internet connectivity is through a cable or DSL "Modem", the External + Interface will be the Ethernet adapter that is connected to that +"Modem" (e.g., eth0) unless you connect via Point-to-Point + Protocol over Ethernet (PPPoE) or Point-to-Point + Tunneling Protocol (PPTP) in which case the External +Interface will be a ppp interface (e.g., ppp0). If you connect +via a regular modem, your External Interface will also be ppp0. +If you connect using ISDN, you external interface will be ippp0.
+ ++ +
+ If your external interface is ppp0 or ippp0 then +you will want to set CLAMPMSS=yes in +/etc/shorewall/shorewall.conf.
Your Local Interface will be an Ethernet adapter (eth0, + eth1 or eth2) and will be connected to a hub or switch. Your local computers + will be connected to the same switch (note: If you have only a single +local system, you can connect the firewall directly to the computer using +a cross-over cable).
+ +Your DMZ Interface will also be an Ethernet adapter + (eth0, eth1 or eth2) and will be connected to a hub or switch. Your DMZ + computers will be connected to the same switch (note: If you have only +a single DMZ system, you can connect the firewall directly to the computer + using a cross-over cable).
+ ++ +
+ Do not connect more than one interface to the same hub or +switch (even for testing). It won't work the way that you expect it to +and you will end up confused and believing that Linux networking doesn't +work at all.
For the remainder of this Guide, we will assume that:
+ ++
+ +- +
+The external interface is eth0.
+- +
+The Local interface is eth1.
+- +
+ +The DMZ interface is eth2.
+The Shorewall default configuration does not define the contents + of any zone. To define the above configuration using the /etc/shorewall/interfaces + file, that file would might contain:
+ ++++ +
++ +Zone +Interface +Broadcast +Options ++ +net +eth0 +detect +norfc1918 ++ +loc +eth1 +detect ++ + + + +dmz +eth2 +detect ++ +
- You may define more complicated zones using the + +
Example:
+ +++ ++ +
++ +Zone +Interface +Broadcast +Options ++ +net +eth0 +detect +norfc1918 ++ +loc +eth1 +detect ++ + + + +loc +eth2 +detect +dhcp +++ +When you have more than one interface to a zone, you will + usually want a policy that permits intra-zone traffic:
+++ ++++ +
++ +Source Zone +Destination Zone +Policy +Log Level +Limit:Burst ++ + + +loc +loc +ACCEPT ++ + - + cases, that isn't necessary.
+ You may define more complicated zones using the /etc/shorewall/hosts file but in most - cases, that isn't necessary.
4.0 Addressing, Subnets and Routing
- +Normally, your ISP will assign you a set of Public - IP addresses. You will configure your firewall's external interface to + IP addresses. You will configure your firewall's external interface to use one of those addresses permanently and you will then have to decide how you are going to use the rest of your addresses. Before we tackle that question though, some background is in order.
- +If you are thoroughly familiar with IP addressing and routing, - you may go to the next section.
- + you may go to the next section. +The following discussion barely scratches the surface of addressing and routing. If you are interested in learning more about this subject, I highly recommend "IP Fundamentals: What Everyone Needs to Know about Addressing & Routing", Thomas A. Maufer, Prentice-Hall, 1999, ISBN 0-13-975483-0.
- +4.1 IP Addresses
- +IP version 4 (IPv4) addresses are 32-bit numbers. - The notation w.x.y.z refers to an address where the high-order byte has -value "w", the next byte has value "x", etc. If we take the address 192.0.2.14 - and express it in hexadecimal, we get:
- -+ The notation w.x.y.z refers to an address where the high-order byte has + value "w", the next byte has value "x", etc. If we take the address 192.0.2.14 + and express it in hexadecimal, we get: + ++- +C0.00.02.0E
-or looking at it as a 32-bit integer
- -+ ++- +C000020E
-4.2 Subnets
- +You will still hear the terms "Class A network", "Class B - network" and "Class C network". In the early days of IP, networks only - came in three sizes (there were also Class D networks but they were used - differently):
- -+ network" and "Class C network". In the early days of IP, networks only + came in three sizes (there were also Class D networks but they were used + differently): + ++- +Class A - netmask 255.0.0.0, size = 2 ** 24
- +Class B - netmask 255.255.0.0, size = 2 ** 16
- +Class C - netmask 255.255.255.0, size = 256
-The class of a network was uniquely determined by the value - of the high order byte of its address so you could look at an IP address - and immediately determine the associated netmask. The netmask is - a number that when logically ANDed with an address isolates the network - number; the remainder of the address is the host number. For - example, in the Class C address 192.0.2.14, the network number is hex C00002 - and the host number is hex 0E.
- + of the high order byte of its address so you could look at an IP address + and immediately determine the associated netmask. The netmask +is a number that when logically ANDed with an address isolates the network + number; the remainder of the address is the host number. For + example, in the Class C address 192.0.2.14, the network number is hex +C00002 and the host number is hex 0E. +As the internet grew, it became clear that such a gross partitioning of the 32-bit address space was going to be very limiting (early on, large corporations and universities were assigned their own class A network!). @@ -508,2000 +512,2008 @@ After some false starts, the current technique of subnetting these networks into smaller subnetworks evolved; that technique is referred to as Classless InterDomain Routing (CIDR). Today, any system that you are likely to work with will understand CIDR and Class-based networking - is largely a thing of the past.
- + is largely a thing of the past. +A subnetwork (often referred to as a subnet) is - a contiguous set of IP addresses such that:
- + a contiguous set of IP addresses such that: +-
- +- +
- -
The number of addresses in the set is a power of 2; and
-- +
+- -
The first address in the set is a multiple of the set - size.
-- + size. +
+- -
The first address in the subnet is reserved and is referred - to as the subnet address.
-- + to as the subnet address. +
+- - + broadcast address. + +
The last address in the subnet is reserved as the subnet's - broadcast address.
-As you can see by this definition, in each subnet of size - n there are (n - 2) usable addresses (addresses that can - be assigned to hosts). The first and last address in the subnet are -used for the subnet address and subnet broadcast address respectively. + n there are (n - 2) usable addresses (addresses that +can be assigned to hosts). The first and last address in the subnet +are used for the subnet address and subnet broadcast address respectively. Consequently, small subnetworks are more wasteful of IP addresses than are large ones.
- +Since n is a power of two, we can easily calculate - the Natural Logarithm (log2) of n. For the more + the Natural Logarithm (log2) of n. For the more common subnet sizes, the size and its natural logarithm are given in the following table:
- -+ ++- +- -
-- -n -log2 n -(32 - log2 n) -- -8 -3 -29 -- -16 -4 -28 -- -32 -5 -27 -- -64 -6 -26 -- -128 -7 -25 -- -256 -8 -24 -- -512 -9 -23 -- -1024 -10 -22 -- -2048 -11 -21 -- -4096 -12 -20 -- -8192 -13 -19 -- -16384 -14 -18 -- -32768 -15 -17 -- - - + +65536 -16 -16 -+ +n +log2 n +(32 - log2 n) ++ +8 +3 +29 ++ +16 +4 +28 ++ +32 +5 +27 ++ +64 +6 +26 ++ +128 +7 +25 ++ +256 +8 +24 ++ +512 +9 +23 ++ +1024 +10 +22 ++ +2048 +11 +21 ++ +4096 +12 +20 ++ +8192 +13 +19 ++ +16384 +14 +18 ++ +32768 +15 +17 ++ + +65536 +16 +16 +You will notice that the above table also contains a column - for (32 - log2 n). That number is the Variable Length Subnet - Mask for a network of size n. From the above table, we can - derive the following one which is a little easier to use.
- -+ for (32 - log2 n). That number is the Variable Length Subnet + Mask for a network of size n. From the above table, we can + derive the following one which is a little easier to use. + ++- +- -
-- -Size of Subnet -VLSM -Subnet Mask -- -8 -/29 -255.255.255.248 -- -16 -/28 -255.255.255.240 -- -32 -/27 -255.255.255.224 -- -64 -/26 -255.255.255.192 -- -128 -/25 -255.255.255.128 -- -256 -/24 -255.255.255.0 -- -512 -/23 -255.255.254.0 -- -1024 -/22 -255.255.252.0 -- -2048 -/21 -255.255.248.0 -- -4096 -/20 -255.255.240.0 -- -8192 -/19 -255.255.224.0 -- -16384 -/18 -255.255.192.0 -- -32768 -/17 -255.255.128.0 -- -65536 -/16 -255.255.0.0 -- - - + +2 ** 24 -/8 -255.0.0.0 -+ +Size of Subnet +VLSM +Subnet Mask ++ +8 +/29 +255.255.255.248 ++ +16 +/28 +255.255.255.240 ++ +32 +/27 +255.255.255.224 ++ +64 +/26 +255.255.255.192 ++ +128 +/25 +255.255.255.128 ++ +256 +/24 +255.255.255.0 ++ +512 +/23 +255.255.254.0 ++ +1024 +/22 +255.255.252.0 ++ +2048 +/21 +255.255.248.0 ++ +4096 +/20 +255.255.240.0 ++ +8192 +/19 +255.255.224.0 ++ +16384 +/18 +255.255.192.0 ++ +32768 +/17 +255.255.128.0 ++ +65536 +/16 +255.255.0.0 ++ + +2 ** 24 +/8 +255.0.0.0 +Notice that the VLSM is written with a slash ("/") -- you - will often hear a subnet of size 64 referred to as a "slash 26" subnet - and one of size 8 referred to as a "slash 29".
- + will often hear a subnet of size 64 referred to as a "slash 26" subnet + and one of size 8 referred to as a "slash 29". +The subnet's mask (also referred to as its netmask) is - simply a 32-bit number with the first "VLSM" bits set to one and the -remaining bits set to zero. For example, for a subnet of size 64, the -subnet mask has 26 leading one bits:
- -+ simply a 32-bit number with the first "VLSM" bits set to one and the + remaining bits set to zero. For example, for a subnet of size 64, the + subnet mask has 26 leading one bits: + ++- + = 255.255.255.192 +11111111111111111111111111000000 = FFFFFFC0 = FF.FF.FF.C0 - = 255.255.255.192
-The subnet mask has the property that if you logically AND - the subnet mask with an address in the subnet, the result is the subnet - address. Just as important, if you logically AND the subnet mask with - an address outside the subnet, the result is NOT the subnet address. + the subnet mask with an address in the subnet, the result is the subnet + address. Just as important, if you logically AND the subnet mask with + an address outside the subnet, the result is NOT the subnet address. As we will see below, this property of subnet masks is very useful in routing.
- +For a subnetwork whose address is a.b.c.d and whose - Variable Length Subnet Mask is /v, we denote the subnetwork as - "a.b.c.d/v" using CIDR Notation.
- + Variable Length Subnet Mask is /v, we denote the subnetwork +as "a.b.c.d/v" using CIDR Notation. +Example:
- -+ ++- +- -
-- -Subnet: -10.10.10.0 - 10.10.10.127 -- -Subnet Size: -128 -- -Subnet Address: -10.10.10.0 -- -Broadcast Address: -10.10.10.127 -- - - + +CIDR Notation: -10.10.10.0/25 -+ +Subnet: +10.10.10.0 - 10.10.10.127 ++ +Subnet Size: +128 ++ +Subnet Address: +10.10.10.0 ++ +Broadcast Address: +10.10.10.127 ++ + +CIDR Notation: +10.10.10.0/25 +There are two degenerate subnets that need mentioning; namely, - the subnet with one member and the subnet with 2 ** 32 members.
- -+ the subnet with one member and the subnet with 2 ** 32 members. + +- -- -
-- -Size of Subnetwork -VLSM Length -Subnet Mask -CIDR Notation -- -1 -32 -255.255.255.255 -a.b.c.d/32 -- - - + +2 ** 32 -0 -0.0.0.0 -0.0.0.0/0 -+ +Size of Subnetwork +VLSM Length +Subnet Mask +CIDR Notation ++ +1 +32 +255.255.255.255 +a.b.c.d/32 ++ + +2 ** 32 +0 +0.0.0.0 +0.0.0.0/0 +So any address a.b.c.d may also be written a.b.c.d/32 - and the set of all possible IP addresses is written 0.0.0.0/0.
- -Later in this guide, you will see the notation a.b.c.d/v - used to describe the ip configuration of a network interface (the 'ip' -utility also uses this syntax). This simply means that the interface is -configured with ip address a.b.c.d and with the netmask that corresponds -to VLSM /v.
- -Example: 192.0.2.65/29
- -The interface is configured with IP address 192.0.2.65 - and netmask 255.255.255.248.
- -4.3 Routing
- -One of the purposes of subnetting is that it forms the basis - for routing. Here's the routing table on my firewall:
- --- + +--[root@gateway root]# netstat -nr
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
192.168.9.1 0.0.0.0 255.255.255.255 UH 40 0 0 texas
206.124.146.177 0.0.0.0 255.255.255.255 UH 40 0 0 eth1
206.124.146.180 0.0.0.0 255.255.255.255 UH 40 0 0 eth3
192.168.3.0 0.0.0.0 255.255.255.0 U 40 0 0 eth3
192.168.2.0 0.0.0.0 255.255.255.0 U 40 0 0 eth1
192.168.1.0 0.0.0.0 255.255.255.0 U 40 0 0 eth2
206.124.146.0 0.0.0.0 255.255.255.0 U 40 0 0 eth0
192.168.9.0 192.0.2.223 255.255.255.0 UG 40 0 0 texas
127.0.0.0 0.0.0.0 255.0.0.0 U 40 0 0 lo
0.0.0.0 206.124.146.254 0.0.0.0 UG 40 0 0 eth0
[root@gateway root]#So any address a.b.c.d may also be written a.b.c.d/32 + and the set of all possible IP addresses is written 0.0.0.0/0.
+ +Later in this guide, you will see the notation a.b.c.d/v + used to describe the ip configuration of a network interface (the 'ip' + utility also uses this syntax). This simply means that the interface is + configured with ip address a.b.c.d and with the netmask that corresponds + to VLSM /v.
+ +Example: 192.0.2.65/29
+ +The interface is configured with IP address 192.0.2.65 + and netmask 255.255.255.248.
+ +4.3 Routing
+ +One of the purposes of subnetting is that it forms the basis + for routing. Here's the routing table on my firewall:
+ +++++[root@gateway root]# netstat -nr+
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
192.168.9.1 0.0.0.0 255.255.255.255 UH 40 0 0 texas
206.124.146.177 0.0.0.0 255.255.255.255 UH 40 0 0 eth1
206.124.146.180 0.0.0.0 255.255.255.255 UH 40 0 0 eth3
192.168.3.0 0.0.0.0 255.255.255.0 U 40 0 0 eth3
192.168.2.0 0.0.0.0 255.255.255.0 U 40 0 0 eth1
192.168.1.0 0.0.0.0 255.255.255.0 U 40 0 0 eth2
206.124.146.0 0.0.0.0 255.255.255.0 U 40 0 0 eth0
192.168.9.0 192.0.2.223 255.255.255.0 UG 40 0 0 texas
127.0.0.0 0.0.0.0 255.0.0.0 U 40 0 0 lo
0.0.0.0 206.124.146.254 0.0.0.0 UG 40 0 0 eth0
[root@gateway root]#The device texas is a GRE tunnel to a peer site in - the Dallas, Texas area.
- + the Dallas, Texas area.
-
- The first three routes are host routes since they indicate how - to get to a single host. In the 'netstat' output this can be seen by the - "Genmask" (Subnet Mask) of 255.255.255.255 and the "H" in the Flags column. - The remainder are 'net' routes since they tell the kernel how to route -packets to a subnetwork. The last route is the default route and -the gateway mentioned in that route is called the default gateway.
+
+ The first three routes are host routes since they indicate +how to get to a single host. In the 'netstat' output this can be seen +by the "Genmask" (Subnet Mask) of 255.255.255.255 and the "H" in the +Flags column. The remainder are 'net' routes since they tell the kernel +how to route packets to a subnetwork. The last route is the default + route and the gateway mentioned in that route is called the default + gateway. +When the kernel is trying to send a packet to IP address A, it starts at the top of the routing table and:
- +-
- -- +
- -
A is logically ANDed with the 'Genmask' value in the table entry.
-- +
+- -
The result is compared with the 'Destination' value in - the table entry.
-- + the table entry. +
+- +
If the result and the 'Destination' value are the same, - then:
- + then: +-
- +
- -
If the 'Gateway' column is non-zero, the packet is - sent to the gateway over the interface named in the 'Iface' column.
-- + sent to the gateway over the interface named in the 'Iface' column. +
+- - + the interface named in the 'iface' column. +
Otherwise, the packet is sent directly to A over - the interface named in the 'iface' column.
-- +
+- - + in the table. + + - +
Otherwise, the above steps are repeated on the next entry - in the table.
-Since the default route matches any IP address (A land 0.0.0.0 = 0.0.0.0), packets that don't match any of the other routing table entries are sent to the default gateway which is usually a router at your ISP.
- +Lets take an example. Suppose that we want to route a packet - to 192.168.1.5. That address clearly doesn't match any of the host routes - in the table but if we logically and that address with 255.255.255.0, + to 192.168.1.5. That address clearly doesn't match any of the host routes + in the table but if we logically and that address with 255.255.255.0, the result is 192.168.1.0 which matches this routing table entry:
- --++ ++- +- + +192.168.1.0 0.0.0.0 255.255.255.0 U 40 0 0 eth2-So to route a packet to 192.168.1.5, the packet is sent directly over eth2.
-One more thing needs to be emphasized -- all outgoing packet - are sent using the routing table and reply packets are not a special case. - There seems to be a common mis-conception whereby people think that request - packets are like salmon and contain a genetic code that is magically transferred - to reply packets so that the replies follow the reverse route taken by -the request. That isn't the case; the replies may take a totally different -route back to the client than was taken by the requests -- they are totally -independent.
- + are sent using the routing table and reply packets are not a special +case. There seems to be a common mis-conception whereby people think +that request packets are like salmon and contain a genetic code that +is magically transferred to reply packets so that the replies follow +the reverse route taken by the request. That isn't the case; the replies +may take a totally different route back to the client than was taken by +the requests -- they are totally independent. +4.4 Address Resolution Protocol
- +When sending packets over Ethernet, IP addresses aren't used. - Rather Ethernet addressing is based on Media Access Control (MAC) - addresses. Each Ethernet device has it's own unique MAC address which -is burned into a PROM on the device during manufacture. You can obtain + Rather Ethernet addressing is based on Media Access Control (MAC) + addresses. Each Ethernet device has it's own unique MAC address which + is burned into a PROM on the device during manufacture. You can obtain the MAC of an Ethernet device using the 'ip' utility:
- --- -+ +++- --[root@gateway root]# ip addr show eth0-
2: eth0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc htb qlen 100
link/ether 02:00:08:e3:fa:55 brd ff:ff:ff:ff:ff:ff
inet 206.124.146.176/24 brd 206.124.146.255 scope global eth0
inet 206.124.146.178/24 brd 206.124.146.255 scope global secondary eth0
inet 206.124.146.179/24 brd 206.124.146.255 scope global secondary eth0
[root@gateway root]#++ + +- -As you can see from the above output, the MAC is 6 bytes (48 bits) wide. A card's MAC is usually also printed on a label attached to the card itself.
-++ +- -Because IP uses IP addresses and Ethernet uses MAC addresses, - a mechanism is required to translate an IP address into a MAC address; - that is the purpose of the Address Resolution Protocol (ARP). -Here is ARP in action:
--- --+ a mechanism is required to translate an IP address into a MAC address; + that is the purpose of the Address Resolution Protocol (ARP). + Here is ARP in action: ++ +++ ++++[root@gateway root]# tcpdump -nei eth2 arp+
tcpdump: listening on eth2
09:56:49.766757 2:0:8:e3:4c:48 0:6:25:aa:8a:f0 arp 42: arp who-has 192.168.1.19 tell 192.168.1.254
09:56:49.769372 0:6:25:aa:8a:f0 2:0:8:e3:4c:48 arp 60: arp reply 192.168.1.19 is-at 0:6:25:aa:8a:f0
2 packets received by filter
0 packets dropped by kernel
[root@gateway root]#In this exchange, 192.168.1.254 (MAC 2:0:8:e3:4c:48) wants + to know the MAC of the device with IP address 192.168.1.19. The system + having that IP address is responding that the MAC address of the device + with IP address 192.168.1.19 is 0:6:25:aa:8a:f0.
+ +In order to avoid having to exchange ARP information each + time that an IP packet is to be sent, systems maintain an ARP cache + of IP<->MAC correspondences. You can see the ARP cache on your +system (including your Windows system) using the 'arp' command:
+ ++-+[root@gateway root]# arp -na
? (206.124.146.177) at 00:A0:C9:15:39:78 [ether] on eth1
? (192.168.1.3) at 00:A0:CC:63:66:89 [ether] on eth2
? (192.168.1.5) at 00:A0:CC:DB:31:C4 [ether] on eth2
? (206.124.146.254) at 00:03:6C:8A:18:38 [ether] on eth0
? (192.168.1.19) at 00:06:25:AA:8A:F0 [ether] on eth2In this exchange, 192.168.1.254 (MAC 2:0:8:e3:4c:48) wants - to know the MAC of the device with IP address 192.168.1.19. The system -having that IP address is responding that the MAC address of the device -with IP address 192.168.1.19 is 0:6:25:aa:8a:f0.
- -In order to avoid having to exchange ARP information each - time that an IP packet is to be sent, systems maintain an ARP cache - of IP<->MAC correspondences. You can see the ARP cache on your system - (including your Windows system) using the 'arp' command:
- --- +--[root@gateway root]# arp -na-
? (206.124.146.177) at 00:A0:C9:15:39:78 [ether] on eth1
? (192.168.1.3) at 00:A0:CC:63:66:89 [ether] on eth2
? (192.168.1.5) at 00:A0:CC:DB:31:C4 [ether] on eth2
? (206.124.146.254) at 00:03:6C:8A:18:38 [ether] on eth0
? (192.168.1.19) at 00:06:25:AA:8A:F0 [ether] on eth2The leading question marks are a result of my having specified - the 'n' option (Windows 'arp' doesn't allow that option) which causes + the 'n' option (Windows 'arp' doesn't allow that option) which causes the 'arp' program to forego IP->DNS name translation. Had I not given that option, the question marks would have been replaced with the FQDN corresponding to each IP address. Notice that the last entry in the table records the information we saw using tcpdump above.
- +4.5 RFC 1918
- +IP addresses are allocated by the Internet Assigned Number Authority (IANA) - who delegates allocations on a geographic basis to Regional Internet - Registries (RIRs). For example, allocation for the Americas and for - sub-Sahara Africa is delegated to the American - Registry for Internet Numbers (ARIN). These RIRs may in turn delegate - to national registries. Most of us don't deal with these registrars but - rather get our IP addresses from our ISP.
- + who delegates allocations on a geographic basis to Regional Internet + Registries (RIRs). For example, allocation for the Americas and for + sub-Sahara Africa is delegated to the American + Registry for Internet Numbers (ARIN). These RIRs may in turn +delegate to national registries. Most of us don't deal with these registrars +but rather get our IP addresses from our ISP. +It's a fact of life that most of us can't afford as many Public IP addresses as we have devices to assign them to so we end up making use of Private IP addresses. RFC 1918 reserves several IP address ranges for this purpose:
- -+ ++- -10.0.0.0 - 10.255.255.255-
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255++ +- -The addresses reserved by RFC 1918 are sometimes referred - to as non-routable because the Internet backbone routers don't - forward packets which have an RFC-1918 destination address. This is understandable - given that anyone can select any of these addresses for their private - use.
-+ to as non-routable because the Internet backbone routers don't + forward packets which have an RFC-1918 destination address. This is +understandable given that anyone can select any of these addresses +for their private use. ++ +- -When selecting addresses from these ranges, there's a couple - of things to keep in mind:
-+ of things to keep in mind: ++ +- --
-- +
- -
As the IPv4 address space becomes depleted, more and more organizations (including ISPs) are beginning to use RFC 1918 addresses - in their infrastructure.
-- + in their infrastructure. +
+- - + your ISP or by another organization with whom you want to establish + a VPN relationship. + +
You don't want to use addresses that are being used by - your ISP or by another organization with whom you want to establish - a VPN relationship.
-++ +- -So it's a good idea to check with your ISP to see if they - are using (or are planning to use) private addresses before you decide - the addresses that you are going to use.
-+ are using (or are planning to use) private addresses before you decide + the addresses that you are going to use. ++ + - -++ +- -The choice of how to set up your network depends primarily - on how many Public IP addresses you have vs. how many addressable entities - you have in your network. Regardless of how many addresses you have, -your ISP will handle that set of addresses in one of two ways:
-+ on how many Public IP addresses you have vs. how many addressable entities + you have in your network. Regardless of how many addresses you have, + your ISP will handle that set of addresses in one of two ways: ++ +- --
-- +
- -
Routed - Traffic to any of your addresses will - be routed through a single gateway address. This will generally - only be done if your ISP has assigned you a complete subnet (/29 or + be routed through a single gateway address. This will generally + only be done if your ISP has assigned you a complete subnet (/29 or larger). In this case, you will assign the gateway address as the IP address of your firewall/router's external interface.
-- +
+- - + of your addresses directly. + +
Non-routed - Your ISP will send traffic to each - of your addresses directly.
-++ +- -In the subsections that follow, we'll look at each of these - separately.
- + separately.
-
+ +Before we begin, there is one thing for you to check:
- +- + If you are using the Debian package, please check your shorewall.conf + file to ensure that the following are set correctly; if they are not, change + them appropriately:
- If you are using the Debian package, please check your shorewall.conf - file to ensure that the following are set correctly; if they are not, change - them appropriately:
-
+ +-
-- NAT_ENABLED=Yes
-- IP_FORWARDING=On
- +
-- NAT_ENABLED=Yes
+- IP_FORWARDING=On
+
+++ + - -++ +- -Let's assume that your ISP has assigned you the subnet 192.0.2.64/28 routed through 192.0.2.65. That means that you have IP addresses - 192.0.2.64 - 192.0.2.79 and that your firewall's external IP address -is 192.0.2.65. Your ISP has also told you that you should use a netmask -of 255.255.255.0 (so your /28 is part of a larger /24). With this many -IP addresses, you are able to subnet your /28 into two /29's and set + 192.0.2.64 - 192.0.2.79 and that your firewall's external IP address + is 192.0.2.65. Your ISP has also told you that you should use a netmask + of 255.255.255.0 (so your /28 is part of a larger /24). With this many + IP addresses, you are able to subnet your /28 into two /29's and set up your network as shown in the following diagram.
-++ +- --
-
+ ++ +- -Here, the DMZ comprises the subnet 192.0.2.64/29 and the Local network is 192.0.2.72/29. The default gateway for hosts in the DMZ would be configured to 192.0.2.66 and the default gateway for hosts in the local network would be 192.0.2.73.
-++ +- -Notice that this arrangement is rather wasteful of public - IP addresses since it is using 192.0.2.64 and 192.0.2.72 for subnet + IP addresses since it is using 192.0.2.64 and 192.0.2.72 for subnet addresses, 192.0.2.71 and 192.0.2.79 for subnet broadcast addresses and 192.0.2.66 and 168.0.2.73 for internal addresses on the firewall/router. Nevertheless, it shows how subnetting can work and if we were dealing with a /24 rather than a /28 network, the use of 6 IP addresses out of 256 would be justified because of the simplicity of the setup.
-++ +- -The astute reader may have noticed that the Firewall/Router's - external interface is actually part of the DMZ subnet (192.0.2.64/29). - What if DMZ 1 (192.0.2.67) tries to communicate with 192.0.2.65? The -routing table on DMZ 1 will look like this:
--+ ++ external interface is actually part of the DMZ subnet (192.0.2.64/29). + What if DMZ 1 (192.0.2.67) tries to communicate with 192.0.2.65? The + routing table on DMZ 1 will look like this: ++- --Kernel IP routing table-
Destination Gateway Genmask Flags MSS Window irtt Iface
192.0.2.64 0.0.0.0 255.255.255.248 U 40 0 0 eth0
0.0.0.0 192.0.2.66 0.0.0.0 UG 40 0 0 eth0+ ++ +- -This means that DMZ 1 will send an ARP "who-has 192.0.2.65" - request and no device on the DMZ Ethernet segment has that IP address. - Oddly enough, the firewall will respond to the request with the MAC + request and no device on the DMZ Ethernet segment has that IP address. + Oddly enough, the firewall will respond to the request with the MAC address of its DMZ Interface!! DMZ 1 can then send Ethernet frames addressed to that MAC address and the frames will be received (correctly) by the firewall/router.
-++ +- -It is this rather unexpected ARP behavior on the part of the Linux Kernel that prompts the warning earlier in this guide regarding the connecting of multiple firewall/router interfaces to the same hub or switch. When an ARP request for one of the firewall/router's IP addresses is sent by another system connected to the hub/switch, all of the firewall's - interfaces that connect to the hub/switch can respond! It is then a + interfaces that connect to the hub/switch can respond! It is then a race as to which "here-is" response reaches the sender first.
-++ + - -++ +- -If you have the above situation but it is non-routed, you can configure your network exactly as described above with one additional - twist; simply specify the "proxyarp" option on all three firewall interfaces - in the /etc/shorewall/interfaces file.
-+ twist; simply specify the "proxyarp" option on all three firewall interfaces + in the /etc/shorewall/interfaces file. ++ +- -Most of us don't have the luxury of having enough public IP addresses to set up our networks as shown in the preceding example (even if the setup is routed).
-++ +- -For the remainder of this section, assume that your ISP - has assigned you IP addresses 192.0.2.176-180 and has told you to use - netmask 255.255.255.0 and default gateway 192.0.2.254.
-+ has assigned you IP addresses 192.0.2.176-180 and has told you to use + netmask 255.255.255.0 and default gateway 192.0.2.254. ++ +- -Clearly, that set of addresses doesn't comprise a subnetwork - and there aren't enough addresses for all of the network interfaces. -There are four different techniques that can be used to work around this -problem.
-+ and there aren't enough addresses for all of the network interfaces. + There are four different techniques that can be used to work around +this problem. ++ +- --
-- +
- -
Source Network Address Translation (SNAT).
-- +
+- -
Destination Network Address Translation (DNAT) - also known as Port Forwarding.
-- + also known as Port Forwarding. +
+- -
Proxy ARP.
-- +
+- - + to as Static NAT. + +
Network Address Translation (NAT) also referred - to as Static NAT.
-++ +- -Often a combination of these techniques is used. Each of these will be discussed in the sections that follow.
-++ + - -++ +- -With SNAT, an internal LAN segment is configured using RFC - 1918 addresses. When a host A on this internal segment initiates - a connection to host B on the internet, the firewall/router rewrites - the IP header in the request to use one of your public IP addresses -as the source address. When B responds and the response is received - by the firewall, the firewall changes the destination address back to - the RFC 1918 address of A and forwards the response back to A.
-+ 1918 addresses. When a host A on this internal segment initiates + a connection to host B on the internet, the firewall/router +rewrites the IP header in the request to use one of your public IP +addresses as the source address. When B responds and the response +is received by the firewall, the firewall changes the destination address +back to the RFC 1918 address of A and forwards the response back +to A. ++ +- -Let's suppose that you decide to use SNAT on your local zone - and use public address 192.0.2.176 as both your firewall's external + and use public address 192.0.2.176 as both your firewall's external IP address and the source IP address of internet requests sent from that zone.
-++ +- + +-
-
The local zone has been subnetted as 192.168.201.0/29 - (netmask 255.255.255.248).- + (netmask 255.255.255.248).- +- + The systems in the local zone would be configured with a default + gateway of 192.168.201.1 (the IP address of the firewall's local interface). +- The systems in the local zone would be configured with a default - gateway of 192.168.201.1 (the IP address of the firewall's local interface).
- +- -- SNAT is configured in Shorewall using the /etc/shorewall/masq file.
-++ ++- --- -
-- -INTERFACE -SUBNET -ADDRESS -- - - + +eth0 -192.168.201.0/29 -192.0.2.176 -+ +INTERFACE +SUBNET +ADDRESS ++ + +eth0 +192.168.201.0/29 +192.0.2.176 ++ ++ +- -This example used the normal technique of assigning the same - public IP address for the firewall external interface and for SNAT. + public IP address for the firewall external interface and for SNAT. If you wanted to use a different IP address, you would either have to use your distributions network configuration tools to add that IP address - to the external interface or you could set ADD_SNAT_ALIASES=Yes in - /etc/shorewall/shorewall.conf and Shorewall will add the address for you.
-+ to the external interface or you could set ADD_SNAT_ALIASES=Yes in + /etc/shorewall/shorewall.conf and Shorewall will add the address for you. ++ + - -++ +- -When SNAT is used, it is impossible for hosts on the internet - to initiate a connection to one of the internal systems since those + to initiate a connection to one of the internal systems since those systems do not have a public IP address. DNAT provides a way to allow selected connections from the internet.
-++ +- --
- Suppose that your daughter wants to run a web server on her system - "Local 3". You could allow connections to the internet to her server -by adding the following entry in /etc/shorewall/rules:
-+ ++ Suppose that your daughter wants to run a web server on her +system "Local 3". You could allow connections to the internet to her +server by adding the following entry in /etc/shorewall/rules: ++- --- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -SOURCE PORT -ORIGINAL DESTINATION -- - - + +DNAT -net -loc:192.168.201.4 -tcp -www -- -192.0.2.176 -+ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +SOURCE PORT +ORIGINAL DESTINATION ++ + +DNAT +net +loc:192.168.201.4 +tcp +www +- +192.0.2.176 ++ ++ +- -If one of your daughter's friends at address A wants - to access your daughter's server, she can connect to http://192.0.2.176 (the firewall's external - IP address) and the firewall will rewrite the destination IP address -to 192.168.201.4 (your daughter's system) and forward the request. When -your daughter's server responds, the firewall will rewrite the source -address back to 192.0.2.176 and send the response back to A.
-+ IP address) and the firewall will rewrite the destination IP address + to 192.168.201.4 (your daughter's system) and forward the request. When + your daughter's server responds, the firewall will rewrite the source + address back to 192.0.2.176 and send the response back to A. ++ +- -This example used the firewall's external IP address for DNAT. You can use another of your public IP addresses but Shorewall will not add that address to the firewall's external interface for you.
-++ + - -++ +- -The idea behind proxy ARP is that:
-++ +- --
-- +
- -
A host H behind your firewall is assigned one of your public IP addresses (A) and is assigned the same netmask (M) as the firewall's external interface.
-- +
+- -
The firewall responds to ARP "who has" requests for A. -
-- + +
+- - + +
When H issues an ARP "who has" request for an address in the subnetwork defined by A and M, the firewall will respond (with the MAC if the firewall interface to H).
-++ +- -Let suppose that we decide to use Proxy ARP on the DMZ in - our example network.
-+ our example network. ++ +- + +-
-
Here, we've assigned the IP addresses 192.0.2.177 to - system DMZ 1 and 192.0.2.178 to DMZ 2. Notice that we've just assigned - an arbitrary RFC 1918 IP address and subnet mask to the DMZ interface - on the firewall. That address and netmask isn't relevant - just be sure - it doesn't overlap another subnet that you've defined.- + system DMZ 1 and 192.0.2.178 to DMZ 2. Notice that we've just assigned + an arbitrary RFC 1918 IP address and subnet mask to the DMZ interface + on the firewall. That address and netmask isn't relevant - just be sure + it doesn't overlap another subnet that you've defined. +- +- -- The Shorewall configuration of Proxy ARP is done using the /etc/shorewall/proxyarp file.
-+ ++ The Shorewall configuration of Proxy ARP is done using the + /etc/shorewall/proxyarp file.+- --- -
-- -ADDRESS -INTERFACE -EXTERNAL -HAVE ROUTE -- -192.0.2.177 -eth2 -eth0 -No -- - - + +192.0.2.178 -eth2 -eth0 -No -+ +ADDRESS +INTERFACE +EXTERNAL +HAVE ROUTE ++ +192.0.2.177 +eth2 +eth0 +No ++ + +192.0.2.178 +eth2 +eth0 +No ++ ++ +- -Because the HAVE ROUTE column contains No, Shorewall will - add host routes thru eth2 to 192.0.2.177 and 192.0.2.178.
-
-The ethernet interfaces on DMZ 1 and DMZ 2 should be configured -to have the IP addresses shown but should have the same default gateway as -the firewall itself -- namely 192.0.2.254.
-
-- -- --+ +-+ +A word of warning is in order here. ISPs typically configure - their routers with a long ARP cache timeout. If you move a system from - parallel to your firewall to behind your firewall with Proxy ARP, it will - probably be HOURS before that system can communicate with the internet. -There are a couple of things that you can try:
+
+ add host routes thru eth2 to 192.0.2.177 and 192.0.2.178.
The ethernet interfaces on DMZ 1 and DMZ 2 should be configured + to have the IP addresses shown but should have the same default gateway +as the firewall itself -- namely 192.0.2.254.
+
++ ++ ++- -+- -A word of warning is in order here. ISPs typically configure + their routers with a long ARP cache timeout. If you move a system from + parallel to your firewall to behind your firewall with Proxy ARP, it will + probably be HOURS before that system can communicate with the internet. + There are a couple of things that you can try:
+
+-
- You can determine if your ISP's gateway ARP cache is stale using ping -and tcpdump. Suppose that we suspect that the gateway router has a stale -ARP cache entry for 130.252.100.19. On the firewall, run tcpdump as follows:- (Courtesy of Bradey Honsinger) A reading of Stevens' TCP/IP Illustrated, -Vol 1 reveals that a
-
-
- "gratuitous" ARP packet should cause the ISP's router to refresh their ARP -cache (section 4.7). A gratuitous ARP is simply a host requesting the MAC -address for its own IP; in addition to ensuring that the IP address isn't -a duplicate,...
-
- "if the host sending the gratuitous ARP has just changed its hardware address..., - this packet causes any other host...that has an entry in its cache for the - old hardware address to update its ARP cache entry accordingly."
-
- Which is, of course, exactly what you want to do when you switch a host -from being exposed to the Internet to behind Shorewall using proxy ARP (or -static NAT for that matter). Happily enough, recent versions of Redhat's iputils -package include "arping", whose "-U" flag does just that:
-
- arping -U -I <net if> <newly proxied -IP>
- arping -U -I eth0 66.58.99.83 # for example
-
- Stevens goes on to mention that not all systems respond correctly to gratuitous - ARPs, but googling for "arping -U" seems to support the idea that it works - most of the time.
-
-- You can call your ISP and ask them to purge the stale ARP cache -entry but many either can't or won't purge individual entries.
- +- (Courtesy of Bradey Honsinger) A reading of Stevens' TCP/IP Illustrated, + Vol 1 reveals that a
+
+
+ "gratuitous" ARP packet should cause the ISP's router to refresh their +ARP cache (section 4.7). A gratuitous ARP is simply a host requesting the +MAC address for its own IP; in addition to ensuring that the IP address isn't + a duplicate,...
+
+ "if the host sending the gratuitous ARP has just changed its hardware +address..., this packet causes any other host...that has an entry in its +cache for the old hardware address to update its ARP cache entry accordingly."
+
+ Which is, of course, exactly what you want to do when you switch a host + from being exposed to the Internet to behind Shorewall using proxy ARP (or + static NAT for that matter). Happily enough, recent versions of Redhat's +iputils package include "arping", whose "-U" flag does just that:
+
+ arping -U -I <net if> <newly proxied + IP>
+ arping -U -I eth0 66.58.99.83 # for example
+
+ Stevens goes on to mention that not all systems respond correctly to +gratuitous ARPs, but googling for "arping -U" seems to support the idea +that it works most of the time.
+
+- You can call your ISP and ask them to purge the stale ARP cache + entry but many either can't or won't purge individual entries.
++ You can determine if your ISP's gateway ARP cache is stale using ping + and tcpdump. Suppose that we suspect that the gateway router has a stale + ARP cache entry for 130.252.100.19. On the firewall, run tcpdump as follows:+ +- -tcpdump -nei eth0 icmp-++ +- -Now from 130.252.100.19, ping the ISP's gateway (which we -will assume is 130.252.100.254):
-+ will assume is 130.252.100.254): ++ +-ping 130.252.100.254-++- -We can now observe the tcpdump output:
-++ +- -13:35:12.159321 0:4:e2:20:20:33 0:0:77:95:dd:19 ip 98: 192.0.2.177 > 192.0.2.254: icmp: echo request (DF)-
13:35:12.207615 0:0:77:95:dd:19 0:c0:a8:50:b2:57 ip 98: 192.0.2.254 > 192.0.2.177 : icmp: echo reply++ +- -Notice that the source MAC address in the echo request is - different from the destination MAC address in the echo reply!! In this - case 0:4:e2:20:20:33 was the MAC of the firewall's eth0 NIC while 0:c0:a8:50:b2:57 - was the MAC address of DMZ 1. In other words, the gateway's ARP cache - still associates 192.0.2.177 with the NIC in DMZ 1 rather than with the - firewall's eth0.
-+ different from the destination MAC address in the echo reply!! In this + case 0:4:e2:20:20:33 was the MAC of the firewall's eth0 NIC while 0:c0:a8:50:b2:57 + was the MAC address of DMZ 1. In other words, the gateway's ARP cache + still associates 192.0.2.177 with the NIC in DMZ 1 rather than with +the firewall's eth0. ++ + - -++ +- -With static NAT, you assign local systems RFC 1918 addresses - then establish a one-to-one mapping between those addresses and public - IP addresses. For outgoing connections SNAT occurs and on incoming connections - DNAT occurs. Let's go back to our earlier example involving your daughter's - web server running on system Local 3.
-+ then establish a one-to-one mapping between those addresses and public + IP addresses. For outgoing connections SNAT (Source Network Address +Translation) occurs and on incoming connections DNAT (Destination Network +Address Translation) occurs. Let's go back to our earlier example involving +your daughter's web server running on system Local 3. ++ +- --
-
+ ++ +- -Recall that in this setup, the local network is using SNAT - and is sharing the firewall external IP (192.0.2.176) for outbound connections. - This is done with the following entry in /etc/shorewall/masq:
--+ ++ and is sharing the firewall external IP (192.0.2.176) for outbound +connections. This is done with the following entry in /etc/shorewall/masq: ++- --- -
-- -INTERFACE -SUBNET -ADDRESS -- - - + +eth0 -192.168.201.0/29 -192.0.2.176 -+ +INTERFACE +SUBNET +ADDRESS ++ + +eth0 +192.168.201.0/29 +192.0.2.176 ++ ++ +- --
- Suppose now that you have decided to give your daughter her own - IP address (192.0.2.179) for both inbound and outbound connections. + Suppose now that you have decided to give your daughter her +own IP address (192.0.2.179) for both inbound and outbound connections. You would do that by adding an entry in /etc/shorewall/nat.
-+ +++- --- -
-- -EXTERNAL -INTERFACE -INTERNAL -ALL INTERFACES -LOCAL -- - - + +192.0.2.179 -eth0 -192.168.201.4 -No -No -+ +EXTERNAL +INTERFACE +INTERNAL +ALL INTERFACES +LOCAL ++ + +192.0.2.179 +eth0 +192.168.201.4 +No +No ++ ++ +- -With this entry in place, you daughter has her own IP address - and the other two local systems share the firewall's IP address.
-+ and the other two local systems share the firewall's IP address. ++ +- --
- Once the relationship between 192.0.2.179 and 192.168.201.4 is -established by the nat file entry above, it is no longer appropriate -to use a DNAT rule for you daughter's web server -- you would rather just -use an ACCEPT rule:
-+ ++ Once the relationship between 192.0.2.179 and 192.168.201.4 +is established by the nat file entry above, it is no longer appropriate + to use a DNAT rule for you daughter's web server -- you would rather +just use an ACCEPT rule: ++- --- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -SOURCE PORT -ORIGINAL DESTINATION -- - - + +ACCEPT -net -loc:192.168.201.4 -tcp -www -- - + +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +SOURCE PORT +ORIGINAL DESTINATION ++ + +ACCEPT +net +loc:192.168.201.4 +tcp +www ++ + + ++ + - -++ +- --
- With the default policies, your local systems (Local 1-3) can -access any servers on the internet and the DMZ can't access any other -host (including the firewall). With the exception of DNAT rules which cause address translation and allow -the translated connection request to pass through the firewall, the way -to allow connection requests through your firewall is to use ACCEPT + the translated connection request to pass through the firewall, the +way to allow connection requests through your firewall is to use ACCEPT rules.
++ +- -NOTE: Since the SOURCE PORT and ORIG. DEST. Columns aren't - used in this section, they won't be shown
-+ used in this section, they won't be shown ++ +- -You probably want to allow ping between your zones:
--+ +++- --- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -- -ACCEPT -net -dmz -icmp -echo-request -- -ACCEPT -net -loc -icmp -echo-request -- -ACCEPT -dmz -loc -icmp -echo-request -- - - + +ACCEPT -loc -dmz -icmp -echo-request -+ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT ++ +ACCEPT +net +dmz +icmp +echo-request ++ +ACCEPT +net +loc +icmp +echo-request ++ +ACCEPT +dmz +loc +icmp +echo-request ++ + +ACCEPT +loc +dmz +icmp +echo-request ++ ++ +- -Let's suppose that you run mail and pop3 servers on DMZ 2 - and a Web Server on DMZ 1. The rules that you would need are:
--+ ++ and a Web Server on DMZ 1. The rules that you would need are: ++- --- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -COMMENTS -- -ACCEPT -net -dmz:192.0.2.178 -tcp -smtp -# Mail from the Internet -- -ACCEPT -net -dmz:192.0.2.178 -tcp -pop3 -# Pop3 from the Internet -- -ACCEPT -loc -dmz:192.0.2.178 -tcp -smtp -# Mail from the Local Network -- -ACCEPT -loc -dmz:192.0.2.178 -tcp -pop3 -# Pop3 from the Local Network -- -ACCEPT -fw -dmz:192.0.2.178 -tcp -smtp -# Mail from the Firewall -- -ACCEPT -dmz:192.0.2.178 -net -tcp -smtp -# Mail to the Internet -- -ACCEPT -net -dmz:192.0.2.177 -tcp -http -# WWW from the Net -- -ACCEPT -net -dmz:192.0.2.177 -tcp -https -# Secure HTTP from the Net -- - - + +ACCEPT -loc -dmz:192.0.2.177 -tcp -https -# Secure HTTP from the Local Net -+ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +COMMENTS ++ +ACCEPT +net +dmz:192.0.2.178 +tcp +smtp +# Mail from the Internet ++ +ACCEPT +net +dmz:192.0.2.178 +tcp +pop3 +# Pop3 from the Internet ++ +ACCEPT +loc +dmz:192.0.2.178 +tcp +smtp +# Mail from the Local Network ++ +ACCEPT +loc +dmz:192.0.2.178 +tcp +pop3 +# Pop3 from the Local Network ++ +ACCEPT +fw +dmz:192.0.2.178 +tcp +smtp +# Mail from the Firewall ++ +ACCEPT +dmz:192.0.2.178 +net +tcp +smtp +# Mail to the Internet ++ +ACCEPT +net +dmz:192.0.2.177 +tcp +http +# WWW from the Net ++ +ACCEPT +net +dmz:192.0.2.177 +tcp +https +# Secure HTTP from the Net ++ + +ACCEPT +loc +dmz:192.0.2.177 +tcp +https +# Secure HTTP from the Local Net ++ ++ +- -If you run a public DNS server on 192.0.2.177, you would need to add the following rules:
--+ +++- --- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -COMMENTS -- -ACCEPT -net -dmz:192.0.2.177 -udp -domain -# UDP DNS from the Internet -- -ACCEPT -net -dmz:192.0.2.177 -tcp -domain -# TCP DNS from the internet -- -ACCEPT -fw -dmz:192.0.2.177 -udp -domain -# UDP DNS from firewall -- -ACCEPT -fw -dmz:192.0.2.177 -tcp -domain -# TCP DNS from firewall -- -ACCEPT -loc -dmz:192.0.2.177 -udp -domain -# UDP DNS from the local Net -- -ACCEPT -loc -dmz:192.0.2.177 -tcp -domain -# TCP DNS from the local Net -- -ACCEPT -dmz:192.0.2.177 -net -udp -domain -# UDP DNS to the Internet -- - - + +ACCEPT -dmz:192.0.2.177 -net -tcp -domain -# TCP DNS to the Internet -+ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +COMMENTS ++ +ACCEPT +net +dmz:192.0.2.177 +udp +domain +# UDP DNS from the Internet ++ +ACCEPT +net +dmz:192.0.2.177 +tcp +domain +# TCP DNS from the internet ++ +ACCEPT +fw +dmz:192.0.2.177 +udp +domain +# UDP DNS from firewall ++ +ACCEPT +fw +dmz:192.0.2.177 +tcp +domain +# TCP DNS from firewall ++ +ACCEPT +loc +dmz:192.0.2.177 +udp +domain +# UDP DNS from the local Net ++ +ACCEPT +loc +dmz:192.0.2.177 +tcp +domain +# TCP DNS from the local Net ++ +ACCEPT +dmz:192.0.2.177 +net +udp +domain +# UDP DNS to the Internet ++ + +ACCEPT +dmz:192.0.2.177 +net +tcp +domain +# TCP DNS to the Internet ++ ++ +- -You probably want some way to communicate with your firewall - and DMZ systems from the local network -- I recommend SSH which through - its scp utility can also do publishing and software update distribution.
--+ ++ and DMZ systems from the local network -- I recommend SSH which through + its scp utility can also do publishing and software update distribution. ++- --- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -COMMENTS -- -ACCEPT -loc -dmz -tcp -ssh -# SSH to the DMZ -- - - + +ACCEPT -loc -fw -tcp -ssh -# SSH to the Firewall -+ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +COMMENTS ++ +ACCEPT +loc +dmz +tcp +ssh +# SSH to the DMZ ++ + +ACCEPT +loc +fw +tcp +ssh +# SSH to the Firewall ++ ++ + - -++ +- -The above discussion reflects my personal preference for using Proxy ARP for my servers in my DMZ and SNAT/NAT for my local systems. I prefer to use NAT only in cases where a system that is part of an RFC 1918 subnet needs to have it's own public IP.
-++ +- --
- If you haven't already, it would be a good idea to browse through - /etc/shorewall/shorewall.conf just - to see if there is anything there that might be of interest. You might - also want to look at the other configuration files that you haven't + If you haven't already, it would be a good idea to browse through + /etc/shorewall/shorewall.conf just + to see if there is anything there that might be of interest. You might + also want to look at the other configuration files that you haven't touched yet just to get a feel for the other things that Shorewall can do.
++ +- -In case you haven't been keeping score, here's the final set of configuration files for our sample network. Only those that were modified from the original installation are shown.
-++ +- -/etc/shorewall/interfaces (The "options" will be very site-specific).
--+ +++- --- -
-- -Zone -Interface -Broadcast -Options -- -net -eth0 -detect -norfc1918,routefilter -- -loc -eth1 -detect -- - - - + +dmz -eth2 -detect -- + +Zone +Interface +Broadcast +Options ++ +net +eth0 +detect +norfc1918,routefilter ++ +loc +eth1 +detect ++ + + +dmz +eth2 +detect ++ + ++ +- -The setup described here requires that your network interfaces - be brought up before Shorewall can start. This opens a short window + be brought up before Shorewall can start. This opens a short window during which you have no firewall protection. If you replace 'detect' with the actual broadcast addresses in the entries above, you can bring up Shorewall before you bring up your network interfaces.
--+ +++- --- -
-- -Zone -Interface -Broadcast -Options -- -net -eth0 -192.0.2.255 -norfc1918,routefilter -- -loc -eth1 -192.168.201.7 -- - - - + +dmz -eth2 -192.168.202.7 -- + +Zone +Interface +Broadcast +Options ++ +net +eth0 +192.0.2.255 +norfc1918,routefilter ++ +loc +eth1 +192.168.201.7 ++ + + +dmz +eth2 +192.168.202.7 ++ + ++ +- -/etc/shorewall/masq - Local subnet
--+ +++- --- -
-- -INTERFACE -SUBNET -ADDRESS -- - - + +eth0 -192.168.201.0/29 -192.0.2.176 -+ +INTERFACE +SUBNET +ADDRESS ++ + +eth0 +192.168.201.0/29 +192.0.2.176 ++ ++ +- -/etc/shorewall/proxyarp - DMZ
--+ +++- --- -
-- -ADDRESS -INTERFACE -EXTERNAL -HAVE ROUTE -- -192.0.2.177 -eth2 -eth0 -No -- - - + +192.0.2.178 -eth2 -eth0 -No -+ +ADDRESS +INTERFACE +EXTERNAL +HAVE ROUTE ++ +192.0.2.177 +eth2 +eth0 +No ++ + +192.0.2.178 +eth2 +eth0 +No ++ ++ +- -/etc/shorewall/nat- Daughter's System
--+ +++- --- -
-- -EXTERNAL -INTERFACE -INTERNAL -ALL INTERFACES -LOCAL -- - - + +192.0.2.179 -eth0 -192.168.201.4 -No -No -+ +EXTERNAL +INTERFACE +INTERNAL +ALL INTERFACES +LOCAL ++ + +192.0.2.179 +eth0 +192.168.201.4 +No +No ++ ++ +- -/etc/shorewall/rules
--+ +++- --- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -COMMENTS -- -ACCEPT -net -dmz:192.0.2.178 -tcp -smtp -# Mail from the Internet -- -ACCEPT -net -dmz:192.0.2.178 -tcp -pop3 -# Pop3 from the Internet -- -ACCEPT -loc -dmz:192.0.2.178 -tcp -smtp -# Mail from the Local Network -- -ACCEPT -loc -dmz:192.0.2.178 -tcp -pop3 -# Pop3 from the Local Network -- -ACCEPT -fw -dmz:192.0.2.178 -tcp -smtp -# Mail from the Firewall -- -ACCEPT -dmz:192.0.2.178 -net -tcp -smtp -# Mail to the Internet -- -ACCEPT -net -dmz:192.0.2.178 -tcp -http -# WWW from the Net -- -ACCEPT -net -dmz:192.0.2.178 -tcp -https -# Secure HTTP from the Net -- -ACCEPT -loc -dmz:192.0.2.178 -tcp -https -# Secure HTTP from the Local Net -- -ACCEPT -net -dmz:192.0.2.177 -udp -domain -# UDP DNS from the Internet -- -ACCEPT -net -dmz:192.0.2.177 -tcp -domain -# TCP DNS from the internet -- -ACCEPT -fw -dmz:192.0.2.177 -udp -domain -# UDP DNS from firewall -- -ACCEPT -fw -dmz:192.0.2.177 -tcp -domain -# TCP DNS from firewall -- -ACCEPT -loc -dmz:192.0.2.177 -udp -domain -# UDP DNS from the local Net -- -ACCEPT -loc -dmz:192.0.2.177 -tcp -domain -# TCP DNS from the local Net -- -ACCEPT -dmz:192.0.2.177 -net -udp -domain -# UDP DNS to the Internet -- -ACCEPT -dmz:192.0.2.177 -net -tcp -domain -# TCP DNS to the Internet -- -ACCEPT -net -dmz -icmp -echo-request -# Ping -- -ACCEPT -net -loc -icmp -echo-request -# " -- -ACCEPT -dmz -loc -icmp -echo-request -# " -- -ACCEPT -loc -dmz -icmp -echo-request -# " -- -ACCEPT -loc -dmz -tcp -ssh -# SSH to the DMZ -- - - + +ACCEPT -loc -fw -tcp -ssh -# SSH to the Firewall -+ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +COMMENTS ++ +ACCEPT +net +dmz:192.0.2.178 +tcp +smtp +# Mail from the Internet ++ +ACCEPT +net +dmz:192.0.2.178 +tcp +pop3 +# Pop3 from the Internet ++ +ACCEPT +loc +dmz:192.0.2.178 +tcp +smtp +# Mail from the Local Network ++ +ACCEPT +loc +dmz:192.0.2.178 +tcp +pop3 +# Pop3 from the Local Network ++ +ACCEPT +fw +dmz:192.0.2.178 +tcp +smtp +# Mail from the Firewall ++ +ACCEPT +dmz:192.0.2.178 +net +tcp +smtp +# Mail to the Internet ++ +ACCEPT +net +dmz:192.0.2.178 +tcp +http +# WWW from the Net ++ +ACCEPT +net +dmz:192.0.2.178 +tcp +https +# Secure HTTP from the Net ++ +ACCEPT +loc +dmz:192.0.2.178 +tcp +https +# Secure HTTP from the Local Net ++ +ACCEPT +net +dmz:192.0.2.177 +udp +domain +# UDP DNS from the Internet ++ +ACCEPT +net +dmz:192.0.2.177 +tcp +domain +# TCP DNS from the internet ++ +ACCEPT +fw +dmz:192.0.2.177 +udp +domain +# UDP DNS from firewall ++ +ACCEPT +fw +dmz:192.0.2.177 +tcp +domain +# TCP DNS from firewall ++ +ACCEPT +loc +dmz:192.0.2.177 +udp +domain +# UDP DNS from the local Net ++ +ACCEPT +loc +dmz:192.0.2.177 +tcp +domain +# TCP DNS from the local Net ++ +ACCEPT +dmz:192.0.2.177 +net +udp +domain +# UDP DNS to the Internet ++ +ACCEPT +dmz:192.0.2.177 +net +tcp +domain +# TCP DNS to the Internet ++ +ACCEPT +net +dmz +icmp +echo-request +# Ping ++ +ACCEPT +net +loc +icmp +echo-request +# " ++ +ACCEPT +dmz +loc +icmp +echo-request +# " ++ +ACCEPT +loc +dmz +icmp +echo-request +# " ++ +ACCEPT +loc +dmz +tcp +ssh +# SSH to the DMZ ++ + +ACCEPT +loc +fw +tcp +ssh +# SSH to the Firewall ++ ++ + - -++ +- -Given the collection of RFC 1918 and public addresses in this setup, it only makes sense to have separate internal and external DNS servers. You can combine the two into a single BIND 9 server using Views. If you are not interested in Bind 9 views, you can go to the next section.
-++ +- -Suppose that your domain is foobar.net and you want the two - DMZ systems named www.foobar.net and mail.foobar.net and you want the - three local systems named "winken.foobar.net, blinken.foobar.net and + DMZ systems named www.foobar.net and mail.foobar.net and you want the + three local systems named "winken.foobar.net, blinken.foobar.net and nod.foobar.net. You want your firewall to be known as firewall.foobar.net externally and it's interface to the local network to be know as gateway.foobar.net -and its interface to the dmz as dmz.foobar.net. Let's have the DNS server - on 192.0.2.177 which will also be known by the name ns1.foobar.net.
-+ and its interface to the dmz as dmz.foobar.net. Let's have the DNS server + on 192.0.2.177 which will also be known by the name ns1.foobar.net. ++ +- -The /etc/named.conf file would look like this:
--+ +-+++ ++- -+-- -options {-
directory "/var/named";
listen-on { 127.0.0.1 ; 192.0.2.177; };
};
logging {
channel xfer-log {
file "/var/log/named/bind-xfer.log";
print-category yes;
print-severity yes;
print-time yes;
severity info;
};
category xfer-in { xfer-log; };
category xfer-out { xfer-log; };
category notify { xfer-log; };
};++ +-#-
# This is the view presented to our internal systems
#
view "internal" {
#
# These are the clients that see this view
#
match-clients { 192.168.201.0/29;
192.168.202.0/29;
127.0.0/24;
192.0.2.176/32;
192.0.2.178/32;
192.0.2.179/32;
192.0.2.180/32; };
#
# If this server can't complete the request, it should use outside
# servers to do so
#
recursion yes;
zone "." in {
type hint;
file "int/root.cache";
};
zone "foobar.net" in {
type master;
notify no;
allow-update { none; };
file "int/db.foobar";
};
zone "0.0.127.in-addr.arpa" in {
type master;
notify no;
allow-update { none; };
file "int/db.127.0.0";
};
zone "201.168.192.in-addr.arpa" in {
type master;
notify no;
allow-update { none; };
file "int/db.192.168.201";
};
zone "202.168.192.in-addr.arpa" in {
type master;
notify no;
allow-update { none; };
file "int/db.192.168.202";
};
zone "176.2.0.192.in-addr.arpa" in {
type master;
notify no;
allow-update { none; };
file "db.192.0.2.176";
};
(or status NAT for that matter)
zone "177.2.0.192.in-addr.arpa" in {
type master;
notify no;
allow-update { none; };
file "db.192.0.2.177";
};
zone "178.2.0.192.in-addr.arpa" in {
type master;
notify no;
allow-update { none; };
file "db.192.0.2.178";
};
zone "179.2.0.192.in-addr.arpa" in {
type master;
notify no;
allow-update { none; };
file "db.206.124.146.179";
};
};
#
# This is the view that we present to the outside world
#
view "external" {
match-clients { any; };
#
# If we can't answer the query, we tell the client so
#
recursion no;
zone "foobar.net" in {
type master;
notify yes;
allow-update {none; };
allow-transfer { <secondary NS IP>; };
file "ext/db.foobar";
};
zone "176.2.0.192.in-addr.arpa" in {
type master;
notify yes;
allow-update { none; };
allow-transfer { <secondary NS IP>; };
file "db.192.0.2.176";
};
zone "177.2.0.192.in-addr.arpa" in {
type master;
notify yes;
allow-update { none; };
allow-transfer { <secondary NS IP>; };
file "db.192.0.2.177";
};
zone "178.2.0.192.in-addr.arpa" in {
type master;
notify yes;
allow-update { none; };
allow-transfer { <secondary NS IP>; };
file "db.192.0.2.178";
};
zone "179.2.0.192.in-addr.arpa" in {
type master;
notify yes;
allow-update { none; };
allow-transfer { <secondary NS IP>; };
file "db.192.0.2.179";
};
};++- -Here are the files in /var/named (those not shown are usually - included in your bind disbribution).
- + included in your bind disbribution). +db.192.0.2.176 - This is the reverse zone for the firewall's - external interface
- -+ external interface + +-; ############################################################-
; Start of Authority (Inverse Address Arpa) for 192.0.2.176/32
; Filename: db.192.0.2.176
; ############################################################
@ 604800 IN SOA ns1.foobar.net. netadmin.foobar.net. (
2001102303 ; serial
10800 ; refresh (3 hour)
3600 ; retry (1 hour)
604800 ; expire (7 days)
86400 ) ; minimum (1 day)
;
; ############################################################
; Specify Name Servers for all Reverse Lookups (IN-ADDR.ARPA)
; ############################################################
@ 604800 IN NS ns1.foobar.net.
@ 604800 IN NS <name of secondary ns>.
;
; ############################################################
; Iverse Address Arpa Records (PTR's)
; ############################################################
176.2.0.192.in-addr.arpa. 86400 IN PTR firewall.foobar.net.+ ++ +- -db.192.0.2.177 - This is the reverse zone for the www/DNS - server --+ server +-; ############################################################-
; Start of Authority (Inverse Address Arpa) for 192.0.2.177/32
; Filename: db.192.0.2.177
; ############################################################
@ 604800 IN SOA ns1.foobar.net. netadmin.foobar.net. (
2001102303 ; serial
10800 ; refresh (3 hour)
3600 ; retry (1 hour)
604800 ; expire (7 days)
86400 ) ; minimum (1 day)
;
; ############################################################
; Specify Name Servers for all Reverse Lookups (IN-ADDR.ARPA)
; ############################################################
@ 604800 IN NS ns1.foobar.net.
@ 604800 IN NS <name of secondary ns>.
;
; ############################################################
; Iverse Address Arpa Records (PTR's)
; ############################################################
177.2.0.192.in-addr.arpa. 86400 IN PTR www.foobar.net.+ ++ + +- -db.192.0.2.178 - This is the reverse zone for the mail - server --+ server +-; ############################################################-
; Start of Authority (Inverse Address Arpa) for 192.0.2.178/32
; Filename: db.192.0.2.178
; ############################################################
@ 604800 IN SOA ns1.foobar.net. netadmin.foobar.net. (
2001102303 ; serial
10800 ; refresh (3 hour)
3600 ; retry (1 hour)
604800 ; expire (7 days)
86400 ) ; minimum (1 day)
;
; ############################################################
; Specify Name Servers for all Reverse Lookups (IN-ADDR.ARPA)
; ############################################################
@ 604800 IN NS ns1.foobar.net.
@ 604800 IN NS <name of secondary ns>.
;
; ############################################################
; Iverse Address Arpa Records (PTR's)
; ############################################################
178.2.0.192.in-addr.arpa. 86400 IN PTR mail.foobar.net.+ ++ + +- -db.192.0.2.179 - This is the reverse zone for daughter's - web server's public IP --+ web server's public IP +-; ############################################################-
; Start of Authority (Inverse Address Arpa) for 192.0.2.179/32
; Filename: db.192.0.2.179
; ############################################################
@ 604800 IN SOA ns1.foobar.net. netadmin.foobar.net. (
2001102303 ; serial
10800 ; refresh (3 hour)
3600 ; retry (1 hour)
604800 ; expire (7 days)
86400 ) ; minimum (1 day)
;
; ############################################################
; Specify Name Servers for all Reverse Lookups (IN-ADDR.ARPA)
; ############################################################
@ 604800 IN NS ns1.foobar.net.
@ 604800 IN NS <name of secondary ns>.
;
; ############################################################
; Iverse Address Arpa Records (PTR's)
; ############################################################
179.2.0.192.in-addr.arpa. 86400 IN PTR nod.foobar.net.+ ++ + +- -int/db.127.0.0 - The reverse zone for localhost
--+ +++- --; ############################################################-
; Start of Authority (Inverse Address Arpa) for 127.0.0.0/8
; Filename: db.127.0.0
; ############################################################
@ 604800 IN SOA ns1.foobar.net. netadmin.foobar.net. (
2001092901 ; serial
10800 ; refresh (3 hour)
3600 ; retry (1 hour)
604800 ; expire (7 days)
86400 ) ; minimum (1 day)
; ############################################################
; Specify Name Servers for all Reverse Lookups (IN-ADDR.ARPA)
; ############################################################
@ 604800 IN NS ns1.foobar.net.
; ############################################################
; Iverse Address Arpa Records (PTR's)
; ############################################################
1 86400 IN PTR localhost.foobar.net.+ ++ +- -int/db.192.168.201 - Reverse zone for the local net. This - is only shown to internal clients
--+ ++ is only shown to internal clients ++- --; ############################################################-
; Start of Authority (Inverse Address Arpa) for 192.168.201.0/29
; Filename: db.192.168.201
; ############################################################
@ 604800 IN SOA ns1.foobar.net netadmin.foobar.net. (
2002032501 ; serial
10800 ; refresh (3 hour)
3600 ; retry (1 hour)
604800 ; expire (7 days)
86400 ) ; minimum (1 day)
; ############################################################
; Specify Name Servers for all Reverse Lookups (IN-ADDR.ARPA)
; ############################################################
@ 604800 IN NS ns1.foobar.net.
; ############################################################
; Iverse Address Arpa Records (PTR's)
; ############################################################
1 86400 IN PTR gateway.foobar.net.
2 86400 IN PTR winken.foobar.net.
3 86400 IN PTR blinken.foobar.net.
4 86400 IN PTR nod.foobar.net.+ ++ +- -int/db.192.168.202 - Reverse zone for the firewall's DMZ interface
--+ +-+++ ++- -+--; ############################################################-
; Start of Authority (Inverse Address Arpa) for 192.168.202.0/29
; Filename: db.192.168.202
; ############################################################
@ 604800 IN SOA ns1.foobar.net netadmin.foobar.net. (
2002032501 ; serial
10800 ; refresh (3 hour)
3600 ; retry (1 hour)
604800 ; expire (7 days)
86400 ) ; minimum (1 day)
; ############################################################
; Specify Name Servers for all Reverse Lookups (IN-ADDR.ARPA)
; ############################################################
@ 604800 IN NS ns1.foobar.net.
; ############################################################
; Iverse Address Arpa Records (PTR's)
; ############################################################
1 86400 IN PTR dmz.foobar.net.++- -int/db.foobar - Forward zone for use by internal clients.
--+ +++- --;##############################################################-
; Start of Authority for foobar.net.
; Filename: db.foobar
;##############################################################
@ 604800 IN SOA ns1.foobar.net. netadmin.foobar.net. (
2002071501 ; serial
10800 ; refresh (3 hour)
3600 ; retry (1 hour)
604800 ; expire (7 days)
86400 ); minimum (1 day)
;############################################################
; foobar.net Nameserver Records (NS)
;############################################################
@ 604800 IN NS ns1.foobar.net.
;############################################################
; Foobar.net Office Records (ADDRESS)
;############################################################
localhost 86400 IN A 127.0.0.1
firewall 86400 IN A 192.0.2.176
www 86400 IN A 192.0.2.177
ns1 86400 IN A 192.0.2.177
www 86400 IN A 192.0.2.177
gateway 86400 IN A 192.168.201.1
winken 86400 IN A 192.168.201.2
blinken 86400 IN A 192.168.201.3
nod 86400 IN A 192.168.201.4+ ++ +- -ext/db.foobar - Forward zone for external clients
--+ + - --+++ ++- -+--;##############################################################-
; Start of Authority for foobar.net.
; Filename: db.foobar
;##############################################################
@ 86400 IN SOA ns1.foobar.net. netadmin.foobar.net. (
2002052901 ; serial
10800 ; refresh (3 hour)
3600 ; retry (1 hour)
604800 ; expire (7 days)
86400 ); minimum (1 day)
;############################################################
; Foobar.net Nameserver Records (NS)
;############################################################
@ 86400 IN NS ns1.foobar.net.
@ 86400 IN NS <secondary NS>.
;############################################################
; Foobar.net Foobar Wa Office Records (ADDRESS)
;############################################################
localhost 86400 IN A 127.0.0.1
;
; The firewall itself
;
firewall 86400 IN A 192.0.2.176
;
; The DMZ
;
ns1 86400 IN A 192.0.2.177
www 86400 IN A 192.0.2.177
mail 86400 IN A 192.0.2.178
;
; The Local Network
;
nod 86400 IN A 192.0.2.179
;############################################################
; Current Aliases for foobar.net (CNAME)
;############################################################
;############################################################
; foobar.net MX Records (MAIL EXCHANGER)
;############################################################
foobar.net. 86400 IN A 192.0.2.177
86400 IN MX 0 mail.foobar.net.
86400 IN MX 1 <backup MX>.+++ Your Firewall ++ +- -The installation procedure configures - your system to start Shorewall at system boot.
-+ your system to start Shorewall at system boot. ++ +- -The firewall is started using the "shorewall start" command - and stopped using "shorewall stop". When the firewall is stopped, routing - is enabled on those hosts that have an entry in /etc/shorewall/routestopped. A - running firewall may be restarted using the "shorewall restart" command. - If you want to totally remove any trace of Shorewall from your Netfilter - configuration, use "shorewall clear".
-+ running firewall may be restarted using the "shorewall restart" command. + If you want to totally remove any trace of Shorewall from your Netfilter + configuration, use "shorewall clear". ++ +- --
- Edit the /etc/shorewall/routestopped file and configure those -systems that you want to be able to access the firewall when it is stopped.
+ Edit the /etc/shorewall/routestopped file and configure those + systems that you want to be able to access the firewall when it is +stopped. ++ +- -WARNING: If you are connected to your firewall from - the internet, do not issue a "shorewall stop" command unless you have - added an entry for the IP address that you are connected from to /etc/shorewall/routestopped. Also, I don't recommend using "shorewall restart"; it is better to create - an alternate configuration - and test it using the "shorewall - try" command.
-Last updated 1/13/2003 - alternate configuration + and test it using the "shorewall + try" command.
+ + +Last updated 2/18/2003 - Tom Eastep
- +Copyright 2002, 2003 -Thomas M. Eastep
-
+ Thomas M. Eastep +
+
+
diff --git a/Shorewall-docs/sourceforge_index.htm b/Shorewall-docs/sourceforge_index.htm index f1733f3f1..877ae5862 100644 --- a/Shorewall-docs/sourceforge_index.htm +++ b/Shorewall-docs/sourceforge_index.htm @@ -6,31 +6,34 @@ - + -Shoreline Firewall (Shorewall) 1.3 +Shoreline Firewall (Shorewall) 1.4 -+ + - + - + -
- -+ - + + + + + + - - - + + ++ @@ -40,16 +43,16 @@ - + -+ Shorewall 1.4 - "iptables + made easy" @@ -59,34 +62,36 @@ - - -
- Shorewall - 1.3 - "iptables - made easy" -
- -- - - - -- + + - -+ ++ + + + ++ + +- + -
+ ++ - + + + + + + + + ++ @@ -96,7 +101,8 @@ - + + + -What is it?
@@ -109,11 +115,12 @@ - -The Shoreline Firewall, more commonly known as "Shorewall", is - a Netfilter (iptables) based - firewall that can be used on a dedicated firewall system, a multi-function - gateway/router/server or on a standalone GNU/Linux system.
+ +The Shoreline Firewall, more commonly known as "Shorewall", is + a Netfilter (iptables) + based firewall that can be used on a dedicated firewall system, + a multi-function gateway/router/server or on a standalone GNU/Linux + system.
@@ -125,29 +132,29 @@ - -This program is free software; you can redistribute it and/or modify - it under the terms of - Version 2 of - the GNU General Public License as published by the Free Software - Foundation.
+ +This program is free software; you can redistribute it and/or modify + it under the terms + of Version + 2 of the GNU General Public License as published by the Free Software + Foundation.
+ You should have received + a copy of the GNU General Public License + along with this program; if not, write to + the Free Software Foundation, Inc., 675 Mass + Ave, Cambridge, MA 02139, USA @@ -159,7 +166,7 @@ Software Foundation, Inc., 675 Mass Ave, Cambridge - +
-
+
- This program is distributed - in the hope that it will be useful, but -WITHOUT ANY WARRANTY; without even the implied warranty - of MERCHANTABILITY or FITNESS FOR A PARTICULAR - PURPOSE. See the GNU General Public License - for more details.
+ This program is distributed + in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied + warranty of MERCHANTABILITY or FITNESS FOR +A PARTICULAR PURPOSE. See the GNU General Public License + for more details.
-
+
- You should have received a copy - of the GNU General Public License -along with this program; if not, write to the Free -Software Foundation, Inc., 675 Mass Ave, Cambridge, - MA 02139, USACopyright 2001, 2002, 2003 Thomas M. Eastep
@@ -172,23 +179,25 @@ Software Foundation, Inc., 675 Mass Ave, Cambridge - + +- Congratulations to Jacques and - Eric on the recent release of Bering 1.0 Final!!!
- Jacques Nilo and Eric - Wolzak have a LEAF (router/firewall/gateway on -a floppy, CD or compact flash) distribution called - Bering that features Shorewall-1.3.10 - and Kernel-2.4.18. You can find their work at: - http://leaf.sourceforge.net/devel/jnilo
- + Jacques Nilo +and Eric Wolzak have a LEAF (router/firewall/gateway + on a floppy, CD or compact flash) distribution + called Bering that features + Shorewall-1.3.14 and Kernel-2.4.20. You can find + their work at: http://leaf.sourceforge.net/devel/jnilo + + - + Congratulations to Jacques and Eric +on the recent release of Bering 1.1!!!
News
@@ -203,100 +212,98 @@ a floppy, CD or compact flash) distribution called - -2/8/2003 - Shoreawll 1.3.14
- -3/14/2003 - Shorewall 1.4.0
-
New features include
- + + Shorewall 1.4 represents the +next step in the evolution of Shorewall. The main thrust of the initial +release is simply to remove the cruft that has accumulated in Shorewall +over time.
+
+ Function from 1.3 that has been omitted from this version include:
+-
-- An OLD_PING_HANDLING option has been added to shorewall.conf. -When set to Yes, Shorewall ping handling is as it has always been (see -http://www.shorewall.net/ping.html).
-
-
- When OLD_PING_HANDLING=No, icmp echo (ping) is handled via rules and -policies just like any other connection request. The FORWARDPING=Yes option -in shorewall.conf and the 'noping' and 'filterping' options in /etc/shorewall/interfaces -will all generate an error.
-
-- It is now possible to direct Shorewall to create a "label" such - as "eth0:0" for IP addresses that it creates under ADD_IP_ALIASES=Yes -and ADD_SNAT_ALIASES=Yes. This is done by specifying the label instead -of just the interface name:
-
-
- a) In the INTERFACE column of /etc/shorewall/masq
- b) In the INTERFACE column of /etc/shorewall/nat
-- Support for OpenVPN Tunnels.
-
-
-- Support for VLAN devices with names of the form $DEV.$VID (e.g., -eth0.0)
-
-
-- When an interface name is entered in the SUBNET column of the -/etc/shorewall/masq file, Shorewall previously masqueraded traffic from -only the first subnet defined on that interface. It did not masquerade -traffic from:
-
- a) The subnets associated with other addresses on the interface.
- b) Subnets accessed through local routers.
-
- Beginning with Shorewall 1.3.14, if you enter an interface name in the - SUBNET column, shorewall will use the firewall's routing table to construct - the masquerading/SNAT rules.
-
- Example 1 -- This is how it works in 1.3.14.
-
- -[root@gateway test]# cat /etc/shorewall/masq- -
#INTERFACE SUBNET ADDRESS
eth0 eth2 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE[root@gateway test]# ip route show dev eth2- -
192.168.1.0/24 scope link
192.168.10.0/24 proto kernel scope link src 192.168.10.254[root@gateway test]# shorewall start-
...
Masqueraded Subnets and Hosts:
To 0.0.0.0/0 from 192.168.1.0/24 through eth0 using 206.124.146.176
To 0.0.0.0/0 from 192.168.10.0/24 through eth0 using 206.124.146.176
Processing /etc/shorewall/tos...
- When upgrading to Shorewall 1.3.14, if you have multiple local subnets - connected to an interface that is specified in the SUBNET column of an /etc/shorewall/masq - entry, your /etc/shorewall/masq file will need changing. In most cases, -you will simply be able to remove redundant entries. In some cases though, -you might want to change from using the interface name to listing specific -subnetworks if the change described above will cause masquerading to occur -on subnetworks that you don't wish to masquerade.
-
- Example 2 -- Suppose that your current config is as follows:
-
- -[root@gateway test]# cat /etc/shorewall/masq- -
#INTERFACE SUBNET ADDRESS
eth0 eth2 206.124.146.176
eth0 192.168.10.0/24 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE[root@gateway test]# ip route show dev eth2-
192.168.1.0/24 scope link
192.168.10.0/24 proto kernel scope link src 192.168.10.254
[root@gateway test]#
- In this case, the second entry in /etc/shorewall/masq is no longer - required.
-
- Example 3 -- What if your current configuration is like this?
-
- -[root@gateway test]# cat /etc/shorewall/masq- -
#INTERFACE SUBNET ADDRESS
eth0 eth2 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE[root@gateway test]# ip route show dev eth2-
192.168.1.0/24 scope link
192.168.10.0/24 proto kernel scope link src 192.168.10.254
[root@gateway test]#
- In this case, you would want to change the entry in /etc/shorewall/masq - to:
- -#INTERFACE SUBNET ADDRESS+
eth0 192.168.1.0/24 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE- The MERGE_HOSTS variable in shorewall.conf is no longer supported. + Shorewall 1.4 behavior is the same as 1.3 with MERGE_HOSTS=Yes.
+
+
+- Interface names of the form <device>:<integer> +in /etc/shorewall/interfaces now generate an error.
+
+
+- Shorewall 1.4 implements behavior consistent with OLD_PING_HANDLING=No. + OLD_PING_HANDLING=Yes will generate an error at startup as will specification + of the 'noping' or 'filterping' interface options.
+
+
+- The 'routestopped' option in the /etc/shorewall/interfaces +and /etc/shorewall/hosts files is no longer supported and will generate an +error at startup if specified.
+
+
+- The Shorewall 1.2 syntax for DNAT and REDIRECT rules is no +longer accepted.
+
+
+- The ALLOWRELATED variable in shorewall.conf is no longer supported. + Shorewall 1.4 behavior is the same as 1.3 with ALLOWRELATED=Yes.
+
+
+- The icmp.def file has been removed.
+
+
- The 'multi' interface option is no longer supported. + Shorewall will generate rules for sending packets back out the same interface +that they arrived on in two cases:
2/5/2003 - Shorewall Support included in Webmin 1.060 -
- Webmin version 1.060 now has Shorewall support included as standard. -See http://www.webmin.com - --
+
+
+- There is an explicit policy for the source zone to or +from the destination zone. An explicit policy names both zones and does not +use the 'all' reserved word.
+- There are one or more rules for traffic for the source zone to +or from the destination zone including rules that use the 'all' reserved +word. Exception: if the source zone and destination zone are the same then +the rule must be explicit - it must name the zone in both the SOURCE and +DESTINATION columns.
++ +
+ Changes for 1.4 include:
+ ++
+ + + @@ -304,7 +311,8 @@ See http://www.webmin.com - + +- The /etc/shorewall/shorewall.conf file has been completely +reorganized into logical sections.
+
+
+- LOG and CONTINUE are now a valid actions for a rule (/etc/shorewall/rules).
+
+
+- The firewall script and version file are now installed in +/usr/share/shorewall.
+
+
+- Late arriving DNS replies are now silently dropped in the +common chain by default.
+
+
+- In addition to behaving like OLD_PING_HANDLING=No, Shorewall +1.4 no longer unconditionally accepts outbound ICMP packets. So if you want + to 'ping' from the firewall, you will need the appropriate rule or policy.
+
+
+- 802.11b devices with names of the form wlan<n> now +support the 'maclist' option.
+ +
+
+@@ -312,7 +320,8 @@ See http://www.webmin.com - + +
@@ -320,7 +329,8 @@ See http://www.webmin.com - + + @@ -333,28 +343,32 @@ See http://www.webmin.com - + +- + +
+ - + +
-
- + +
This site is hosted by the generous folks at SourceForge.net
@@ -362,15 +376,78 @@ See http://www.webmin.com - +Donations
-+ + +
-+ + + +
-+ + @@ -378,78 +455,17 @@ See http://www.webmin.com - - - + + ++ + + + + + + + + + + + + + + + + + + + + + + + Shorewall is free +but if you try it and find it useful, please consider making a donation + to Starlight +Children's Foundation. Thanks!
+ +- - - -
- - - - -- - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - -Shorewall is free but -if you try it and find it useful, please consider making a donation - to Starlight Children's -Foundation. Thanks!
- -Updated 2/7/2003 - Tom Eastep - -
+Updated 2/18/2003 - Tom Eastep + +
diff --git a/Shorewall-docs/spam_filters.htm b/Shorewall-docs/spam_filters.htm index b44664292..11ba8eb3d 100644 --- a/Shorewall-docs/spam_filters.htm +++ b/Shorewall-docs/spam_filters.htm @@ -1,62 +1,69 @@ - + - + - + - +
SPAM Filters - +- -
- +- ++ + - - + + + +- SPAM Filters
-- -
-![]()
-
-
Like all of you, I'm concerned about the increasing volume of Unsolicited -Commercial Email (UCE or SPAM). I am therefore sympathetic with those of -you who are installing SPAM filters on your mail servers. A couple of recent -incidents involving mis-configured filters have prompted me to establish -this page to spell out what I will do when these filters bounce list postings.
- -When your SPAM filter bounces/rejects list mail, I will:
- + + +Like all of you, I'm concerned about the increasing volume of Unsolicited + Commercial Email (UCE or SPAM). I am therefore sympathetic with those of +you who are installing SPAM filters on your mail servers. A couple of recent +incidents involving mis-configured filters have prompted me to establish this +page to spell out what I will do when these filters bounce list postings.
+ +When your SPAM filter bounces/rejects list mail and I can identify +who you are, I will:
+-
- -- immediately turn off delivery to you from all Shorewall lists to which -you subscribe.
-- try to send you an email from a source other than shorewall.net
- +- immediately turn off delivery to you from all Shorewall lists to +which you subscribe.
+- try to send you an email from a source other than shorewall.net
+When you have corrected the problem, please let me know and I will re-enable -delivery (or you can reenable delivery yourself).
- + +When you have corrected the problem, please let me know and I will re-enable + delivery (or you can reenable delivery yourself).
+
+Note that many brain-dead spam filters inform the sender that a post was +rejected as spam but fail to provide any clue about the original addressee!!! +If I don't know who you are, I can't tell you about the problem...
+
+Last Updated 1/29/2003 - Tom Eastep
- -Copyright + +
+Copyright © 2001, 2002, 2003 Thomas M. Eastep.
-
+
+
diff --git a/Shorewall-docs/starting_and_stopping_shorewall.htm b/Shorewall-docs/starting_and_stopping_shorewall.htm index f055e0998..c3d8cf4e1 100644 --- a/Shorewall-docs/starting_and_stopping_shorewall.htm +++ b/Shorewall-docs/starting_and_stopping_shorewall.htm @@ -1,13 +1,13 @@ - + - + - + - +Starting and Stopping Shorewall @@ -15,315 +15,316 @@ - +- -
- -+ +- + - - + ++ - - + -Starting/Stopping and Monitoring - the Firewall
+ +Starting/Stopping and Monitoring + the Firewall
-If you have a permanent internet connection such as DSL or Cable, - I recommend that you start the firewall automatically at boot. Once - you have installed "firewall" in your init.d directory, simply type - "chkconfig --add firewall". This will start the firewall in run -levels 2-5 and stop it in run levels 1 and 6. If you want to configure -your firewall differently from this default, you can use the "--level" -option in chkconfig (see "man chkconfig") or using your favorite -graphical run-level editor.
- - - - - - - - -Important Notes:
- -
--
- -- Shorewall startup is disabled by default. Once you have configured - your firewall, you can enable startup by removing the file /etc/shorewall/startup_disabled. - Note: Users of the .deb package must edit /etc/default/shorewall and set - 'startup=1'.
-
-- If you use dialup, you may want to start the firewall in -your /etc/ppp/ip-up.local script. I recommend just placing "shorewall - restart" in that script.
- --
- - - -You can manually start and stop Shoreline Firewall using the "shorewall" +
If you have a permanent internet connection such as DSL or Cable, + I recommend that you start the firewall automatically at boot. Once + you have installed "firewall" in your init.d directory, simply type + "chkconfig --add firewall". This will start the firewall in run + levels 2-5 and stop it in run levels 1 and 6. If you want to configure + your firewall differently from this default, you can use the "--level" + option in chkconfig (see "man chkconfig") or using your favorite + graphical run-level editor.
+ + + + + + + + +Important Notes:
+ +
++
+ +- Shorewall startup is disabled by default. Once you have configured + your firewall, you can enable startup by removing the file /etc/shorewall/startup_disabled. + Note: Users of the .deb package must edit /etc/default/shorewall and +set 'startup=1'.
+
+- If you use dialup, you may want to start the firewall in + your /etc/ppp/ip-up.local script. I recommend just placing "shorewall + restart" in that script.
+ ++
+ + + + +You can manually start and stop Shoreline Firewall using the "shorewall" shell program:
- +-
- If you include the keyword debug as the first argument, then a + If you include the keyword debug as the first argument, then a shell trace of the command is produced as in:- shorewall start - starts the firewall
-- shorewall stop - stops the firewall
-- shorewall restart - stops the firewall (if it's - running) and then starts it again
-- shorewall reset - reset the packet and byte counters - in the firewall
-- shorewall clear - remove all rules and chains -installed by Shoreline Firewall
-- shorewall refresh - refresh the rules involving the broadcast +
- shorewall start - starts the firewall
+- shorewall stop - stops the firewall
+- shorewall restart - stops the firewall (if it's + running) and then starts it again
+- shorewall reset - reset the packet and byte counters + in the firewall
+- shorewall clear - remove all rules and chains + installed by Shoreline Firewall
+- shorewall refresh - refresh the rules involving the broadcast addresses of firewall interfaces and the black and white lists.
- +
- +shorewall debug start 2> /tmp/trace- -The above command would trace the 'start' command and place the trace information -in the file /tmp/trace
- -
-The Shorewall State Diagram is shown at the + +
The above command would trace the 'start' command and place the trace +information in the file /tmp/trace
+ +
+The Shorewall State Diagram is shown at the bottom of this page.
- +
-The "shorewall" program may also be used to monitor the firewall.
- +-
- Finally, the "shorewall" program may be used to dynamically alter the + Finally, the "shorewall" program may be used to dynamically alter the contents of a zone.- shorewall status - produce a verbose report about the firewall - (iptables -L -n -v)
-- shorewall show chain - produce a verbose report about - chain (iptables -L chain -n -v)
-- shorewall show nat - produce a verbose report about the nat +
- shorewall status - produce a verbose report about the firewall + (iptables -L -n -v)
+- shorewall show chain - produce a verbose report about + chain (iptables -L chain -n -v)
+- shorewall show nat - produce a verbose report about the nat table (iptables -t nat -L -n -v)
-- shorewall show tos - produce a verbose report about the mangle - table (iptables -t mangle -L -n -v)
-- shorewall show log - display the last 20 packet log entries.
-- shorewall show connections - displays the IP connections currently - being tracked by the firewall.
-- shorewall - show - tc - displays information - about the traffic control/shaping configuration.
-- shorewall monitor [ delay ] - Continuously display the firewall - status, last 20 log entries and nat. When the log entry display - changes, an audible alarm is sounded.
-- shorewall hits - Produces several reports about the Shorewall +
- shorewall show tos - produce a verbose report about the mangle + table (iptables -t mangle -L -n -v)
+- shorewall show log - display the last 20 packet log entries.
+- shorewall show connections - displays the IP connections +currently being tracked by the firewall.
+- shorewall + show + tc - displays information + about the traffic control/shaping configuration.
+- shorewall monitor [ delay ] - Continuously display the firewall + status, last 20 log entries and nat. When the log entry display + changes, an audible alarm is sounded.
+- shorewall hits - Produces several reports about the Shorewall packet log messages in the current /var/log/messages file.
-- shorewall version - Displays the installed version number.
-- shorewall check - Performs a cursory validation - of the zones, interfaces, hosts, rules and policy files. The "check" command does not parse and validate - the generated iptables commands so even though the "check" command -completes successfully, the configuration may fail to start. See the - recommended way to make configuration changes described below. -
-- shorewall try configuration-directory [ timeout - ] - Restart shorewall using the specified configuration and if an -error occurs or if the timeout option is given and the new configuration - has been up for that many seconds then shorewall is restarted using - the standard configuration.
-- shorewall deny, shorewall reject, shorewall accept and shorewall - save implement dynamic blacklisting.
-- shorewall logwatch (added in version 1.3.2) - Monitors the - LOGFILE and produces an audible alarm when new +
- shorewall version - Displays the installed version number.
+- shorewall check - Performs a cursory validation + of the zones, interfaces, hosts, rules and policy files. The "check" command does not parse and validate + the generated iptables commands so even though the "check" command + completes successfully, the configuration may fail to start. See the + recommended way to make configuration changes described below. +
+- shorewall try configuration-directory [ timeout + ] - Restart shorewall using the specified configuration and if an +error occurs or if the timeout option is given and the new configuration + has been up for that many seconds then shorewall is restarted using + the standard configuration.
+- shorewall deny, shorewall reject, shorewall accept and shorewall + save implement dynamic blacklisting.
+- shorewall logwatch (added in version 1.3.2) - Monitors the + LOGFILE and produces an audible alarm when new Shorewall messages are logged.
- +
- +-
- +- shorewall add interface[:host] zone - Adds +
- shorewall add interface[:host] zone - Adds the specified interface (and host if included) to the specified zone.
-- shorewall delete interface[:host] zone - -Deletes the specified interface (and host if included) from the specified +
- shorewall delete interface[:host] zone - +Deletes the specified interface (and host if included) from the specified zone.
- +Examples:+ +
- -shorewall add ipsec0:192.0.2.24 vpn1 - -- adds the address 192.0.2.24 from interface ipsec0 to the zone vpn1-
- shorewall delete ipsec0:192.0.2.24 vpn1 - -- deletes the address 192.0.2.24 from interface ipsec0 from zone vpn1
-shorewall add ipsec0:192.0.2.24 vpn1 + -- adds the address 192.0.2.24 from interface ipsec0 to the zone vpn1+
+ shorewall delete ipsec0:192.0.2.24 vpn1 + -- deletes the address 192.0.2.24 from interface ipsec0 from zone vpn1
+The shorewall start, shorewall restart, shorewall check and + +
The shorewall start, shorewall restart, shorewall check and shorewall try commands allow you to specify which Shorewall configuration + href="configuration_file_basics.htm#Configs"> Shorewall configuration to use:
- -+ +- -- ++ shorewall try configuration-directory +shorewall [ -c configuration-directory ] {start|restart|check}
-
- shorewall try configuration-directoryIf a configuration-directory is specified, each time that Shorewall - is going to use a file in /etc/shorewall it will first look in the configuration-directory - . If the file is present in the configuration-directory, that + +
If a configuration-directory is specified, each time that Shorewall + is going to use a file in /etc/shorewall it will first look in the configuration-directory + . If the file is present in the configuration-directory, that file will be used; otherwise, the file in /etc/shorewall will be used.
- -When changing the configuration of a production firewall, I recommend - the following:
+ +When changing the configuration of a production firewall, I recommend + the following:
- +-
- -- mkdir /etc/test
+- mkdir /etc/test
-- cd /etc/test
+- cd /etc/test
-- <copy any files that you need to change from /etc/shorewall - to . and change them here>
+- <copy any files that you need to change from /etc/shorewall + to . and change them here>
-- shorewall -c . check
+- shorewall -c . check
-- <correct any errors found by check and check again>
+- <correct any errors found by check and check again>
-- /sbin/shorewall try .
- +- /sbin/shorewall try .
+If the configuration starts but doesn't work, just "shorewall restart" - to restore the old configuration. If the new configuration fails to start, - the "try" command will automatically start the old one for you.
+ +If the configuration starts but doesn't work, just "shorewall restart" + to restore the old configuration. If the new configuration fails to +start, the "try" command will automatically start the old one for you.
- +When the new configuration works then just
- +-
- +- cp * /etc/shorewall
+- cp * /etc/shorewall
-- cd
+- cd
-- rm -rf /etc/test
- +- rm -rf /etc/test
+The Shorewall State Diargram is depicted below.
-
-++ +
- +-
-
+- You will note that the commands that result in state transitions use -the word "firewall" rather than "shorewall". That is because the actual -transitions are done by /usr/lib/shorewall/firewall (/usr/share/shorewall/firewall -on Debian); /sbin/shorewall runs 'firewall" according to the following table:
-
-
- + + You will note that the commands that result in state transitions use +the word "firewall" rather than "shorewall". That is because the actual transitions + are done by /usr/lib/shorewall/firewall (/usr/share/shorewall/firewall on + Debian); /sbin/shorewall runs 'firewall" according to the following table:
+
+- -
-- -shorewall start -
-firewall start -
-- -shorewall stop -
-firewall stop -
-- -shorewall restart -
-firewall restart -
-- -shorewall add -
-firewall add -
-- -shorewall delete -
-firewall delete -
-- -shorewall refresh -
-firewall refresh -
-- - - + +shorewall try -
-firewall -c <new configuration> restart -
- If unsuccessful then firewall start (standard configuration)
- If timeout then firewall restart (standard configuration)
-+ +shorewall start +
+firewall start +
++ +shorewall stop +
+firewall stop +
++ +shorewall restart +
+firewall restart +
++ +shorewall add +
+firewall add +
++ +shorewall delete +
+firewall delete +
++ +shorewall refresh +
+firewall refresh +
++ + +shorewall try +
+firewall -c <new configuration> restart +
+ If unsuccessful then firewall start (standard configuration)
+ If timeout then firewall restart (standard configuration)
+
- -Updated 1/29/2003 - Tom Eastep +
+
+ +Updated 2/10/2003 - Tom Eastep
- -Copyright - © 2001, 2002, 2003 Thomas M. Eastep.
+ +Copyright + © 2001, 2002, 2003 Thomas M. Eastep.
-
+
+
diff --git a/Shorewall-docs/support.htm b/Shorewall-docs/support.htm index 8e6c88b57..ba24f7016 100644 --- a/Shorewall-docs/support.htm +++ b/Shorewall-docs/support.htm @@ -2,128 +2,129 @@ - + - + - + - +Support - + - +- -
- -- ++ + + + + - - + +- - + + -Shorewall Support
--
While I don't answer Shorewall questions - emailed directly to me, I try to spend some time each day answering questions - on the Shorewall Users Mailing List. While I don't answer Shorewall questions + emailed directly to me, I try to spend some time each day answering questions + on the Shorewall Users Mailing List.
- +-Tom Eastep
- +Before Reporting a Problem
-"Well at least you tried to read the documentation, which is a lot more + "Well at least you tried to read the documentation, which is a lot more than some people on this list appear to do."
-
+
+- Wietse Venema - On the Postfix mailing list-
-
- There are a number of sources for -problem solution information. Please try these before you post. - + +
+ There are a number of sources for + problem solution information. Please try these before you post. +- +
- +
-
- +- More than half of the questions posted on the support - list have answers directly accessible from the More than half of the questions posted on the support + list have answers directly accessible from the Documentation Index
-
-
-- The FAQ +
+
+- The FAQ has solutions to more than 20 common problems.
- +- +
-
- +- The Troubleshooting Information contains - a number of tips to help you solve common problems.
- +- The Troubleshooting Information contains + a number of tips to help you solve common problems.
+- +
-
- +- The Errata has links to download updated - components.
- +- The Errata has links to download updated + components.
+- +
-
- +- The Mailing List -Archives search facility can locate posts about similar problems: -
- +- The Mailing List + Archives search facility can locate posts about similar +problems:
+- +
Mailing List Archive Search
- -- - - +Match: - + +
+ + + - +Match: + - Format: - + Format: + - Sort by: - + Sort by: + -
-
- Search:Problem Reporting Guidelines
- "Let me see if I can translate your message into a real-world - example. It would be like saying that you have three rooms at home, - and when you walk into one of the rooms, you detect this strange smell. - Can anyone tell you what that strange smell is?
-
- Now, all of us could do some wonderful guessing as to the -smell and even what's causing it. You would be absolutely amazed -at the range and variety of smells we could come up with. Even more -amazing is that all of the explanations for the smells would be completely -plausible."
-
- + "Let me see if I can translate your message into a real-world + example. It would be like saying that you have three rooms at home, + and when you walk into one of the rooms, you detect this strange smell. + Can anyone tell you what that strange smell is?
+
+ Now, all of us could do some wonderful guessing as to the +smell and even what's causing it. You would be absolutely amazed at +the range and variety of smells we could come up with. Even more amazing +is that all of the explanations for the smells would be completely plausible."
+
+- Russell Mosemann on the Postfix mailing list-
-
+ +
+- +
-
+ +- Please remember we only know what is posted in your message. - Do not leave out any information that appears to be correct, or was mentioned - in a previous post. There have been countless posts by people who were - sure that some part of their configuration was correct when it actually - contained a small error. We tend to be skeptics where detail is lacking.
-
-
-- Please keep in mind that you're asking for free - technical support. Any help we offer is an act of generosity, not an obligation. - Try to make it easy for us to help you. Follow good, courteous practices - in writing and formatting your e-mail. Provide details that we need if - you expect good answers. Exact quoting of error messages, log - entries, command output, and other output is better than a paraphrase or - summary.
-
-
-- Please don't describe your - environment and then ask us to send you custom configuration - files. We're here to answer your questions but we can't - do your job for you.
-
-
-- When reporting a problem, ALWAYS include +
- Please remember we only know what is posted in your message. + Do not leave out any information that appears to be correct, or was +mentioned in a previous post. There have been countless posts by people +who were sure that some part of their configuration was correct when +it actually contained a small error. We tend to be skeptics where detail +is lacking.
+
+
+- Please keep in mind that you're asking for free + technical support. Any help we offer is an act of generosity, not an +obligation. Try to make it easy for us to help you. Follow good, courteous +practices in writing and formatting your e-mail. Provide details that +we need if you expect good answers. Exact quoting of error messages, +log entries, command output, and other output is better than a paraphrase +or summary.
+
+
+- Please don't describe +your environment and then ask us to send you custom +configuration files. We're here to answer your questions but +we can't do your job for you.
+
+
+- When reporting a problem, ALWAYS include this information:
- + ++ +
+
+ +- the exact version of Shorewall you are running.
+ +
+
+ shorewall version
+
++
+ +- the exact kernel version you are running
+ +
+
+ uname -a
+
++
+ +- the complete, exact output of
+ +
+
+ ip addr show
+
++
+ +- the complete, exact output of
+ +
+
+ ip route show
+
++
+- If your kernel is modularized, the exact output from
+
+
+ lsmod
+
+- the exact wording of any
+ping
failure responses
+
+- If you installed Shorewall using one of the QuickStart Guides, +please indicate which one.
+
+
+- If you are running Shorewall under Mandrake using the Mandrake + installation of Shorewall, please say so.
+ +
+
+- -
- --
- -- the exact version of Shorewall you are running.
- -
-
- shorewall version
-
--
- -- the exact kernel version you are running
- -
-
- uname -a
-
--
- -- the complete, exact output of
- -
-
- ip addr show
-
--
- -- the complete, exact output of
- -
-
- ip route show
-
--
- -- If your kernel is modularized, the exact output from
-
-
- lsmod
-
-- the exact wording of any
-ping
failure responses
-
-- If you installed Shorewall using one of the QuickStart Guides, please -indicate which one.
-
-
-- If you are running Shorewall under Mandrake using the Mandrake -installation of Shorewall, please say so.
- -
-
--
- +- NEVER include the output of "iptables -L". Instead, if you are having connection - problems of any kind, post the exact output of
-
- /sbin/shorewall status
-
- Since that command generates a lot of output, we -suggest that you redirect the output to a file and attach the file to +- NEVER include the output of "iptables -L". Instead, if you are having +connection problems of any kind, post the exact output of
-
+
+ /sbin/shorewall status
+
+ Since that command generates a lot of output, we +suggest that you redirect the output to a file and attach the file to your post
-
- /sbin/shorewall status > /tmp/status.txt
-
-- As a general matter, please do not edit the diagnostic - information in an attempt to conceal your IP address, netmask, - nameserver addresses, domain name, etc. These aren't secrets, and concealing - them often misleads us (and 80% of the time, a hacker could derive them - anyway from information contained in the SMTP headers of your post).
- +
+ /sbin/shorewall status > /tmp/status.txt
+
+ +- As a general matter, please do not edit the diagnostic + information in an attempt to conceal your IP address, netmask, + nameserver addresses, domain name, etc. These aren't secrets, and concealing + them often misleads us (and 80% of the time, a hacker could derive them + anyway from information contained in the SMTP headers of your post).
+- +
- +- +
- +
- +- +
-
- +- Do you see any "Shorewall" - messages ("/sbin/shorewall show log") - when you exercise the function that is giving you problems? If - so, include the message(s) in your post along with a copy of your /etc/shorewall/interfaces - file.
-
-
-- Please include any of the Shorewall configuration files - (especially the /etc/shorewall/hosts file if you have modified - that file) that you think are relevant. If you include /etc/shorewall/rules, - please include /etc/shorewall/policy as well (rules are meaningless unless - one also knows the policies).
- +- Do you see any +"Shorewall" messages ("/sbin/shorewall show +log") when you exercise the function that is giving +you problems? If so, include the message(s) in your post along with a +copy of your /etc/shorewall/interfaces file.
+
+
+- Please include any of the Shorewall configuration files + (especially the /etc/shorewall/hosts file if you have modified + that file) that you think are relevant. If you include /etc/shorewall/rules, + please include /etc/shorewall/policy as well (rules are meaningless +unless one also knows the policies).
+- +
- -
- -- -
-
- -- If an error occurs -when you try to "shorewall start", - include a trace (See the Troubleshooting - section for instructions).
- -- -
-
- The author gratefully acknowleges that the above list was heavily - plagiarized from the excellent LEAF document by Ray Olszewski + +- -
-The list server limits posts to 120kb so don't post GIFs of - your network layout, etc. to the Mailing List -- your - post will be rejected.
-+ +
+
+ +- If an error occurs +when you try to "shorewall start", + include a trace (See the Troubleshooting + section for instructions).
+ ++ +
+
+ The author gratefully acknowleges that the above list was heavily + plagiarized from the excellent LEAF document by Ray Olszewski found at http://leaf-project.org/pub/doc/docmanager/docid_1891.html.- + +
+ +The list server limits posts to 120kb so don't post GIFs of + your network layout, etc. to the Mailing List -- your + post will be rejected.
+
- +Please post in plain text
- -- A growing number of MTAs serving list subscribers are rejecting - all HTML traffic. At least one MTA has gone so far as to blacklist shorewall.net - "for continuous abuse" because it has been my policy to allow HTML in -list posts!!
-
- I think that blocking all HTML is a Draconian way to control - spam and that the ultimate losers here are not the spammers but the -list subscribers whose MTAs are bouncing all shorewall.net mail. As -one list subscriber wrote to me privately "These e-mail admin's need -to get a (expletive deleted) life instead of trying to rid the -planet of HTML based e-mail". Nevertheless, to allow subscribers to receive -list posts as must as possible, I have now configured the list server -at shorewall.net to strip all HTML from outgoing posts.
- -Where to Send your Problem Report or to Ask for Help
- --- - - - -If you run Shorewall under Bering -- please post your question or problem - to the LEAF Users - mailing list.
- If you run Shorewall under MandrakeSoft Multi Network Firewall - (MNF) and you have not purchased an MNF license from MandrakeSoft then - you can post non MNF-specific Shorewall questions to the Shorewall users mailing - list. Do not expect to get free MNF support on the list.
- -Otherwise, please post your question or problem to the Shorewall users mailing - list.
-To Subscribe to the mailing list go to http://lists.shorewall.net/mailman/listinfo/shorewall-users - .
- -Last Updated 2/4/2003 - Tom Eastep
- ++ A growing number of MTAs serving list subscribers are rejecting + all HTML traffic. At least one MTA has gone so far as to blacklist shorewall.net + "for continuous abuse" because it has been my policy to allow HTML in + list posts!!
+
+ I think that blocking all HTML is a Draconian way to control + spam and that the ultimate losers here are not the spammers but the list + subscribers whose MTAs are bouncing all shorewall.net mail. As one +list subscriber wrote to me privately "These e-mail admin's need to get +a (expletive deleted) life instead of trying to rid the planet +of HTML based e-mail". Nevertheless, to allow subscribers to receive list +posts as must as possible, I have now configured the list server at shorewall.net +to strip all HTML from outgoing posts.
+ +Where to Send your Problem Report or to Ask for Help
+ +++ + + + +If you run Shorewall under Bering -- please post your question or problem + to the LEAF Users + mailing list.
+ If you run Shorewall under MandrakeSoft Multi Network Firewall + (MNF) and you have not purchased an MNF license from MandrakeSoft then + you can post non MNF-specific Shorewall questions to the Shorewall users mailing + list. Do not expect to get free MNF support on the list.
+ +Otherwise, please post your question or problem to the Shorewall users mailing + list.
+To Subscribe to the mailing list go to http://lists.shorewall.net/mailman/listinfo/shorewall-users + .
+ + +Last Updated 2/9/2003 - Tom Eastep
+Copyright © 2001, 2002, 2003 Thomas M. Eastep.
-
-
-
-
+
+
+
+
diff --git a/Shorewall-docs/traffic_shaping.htm b/Shorewall-docs/traffic_shaping.htm index d1888baa0..8b6828abd 100644 --- a/Shorewall-docs/traffic_shaping.htm +++ b/Shorewall-docs/traffic_shaping.htm @@ -1,324 +1,333 @@ - + - + - + - +Traffic Shaping - +- -
- -- +- + + - - + + + ++ -Traffic Shaping/Control
-Beginning with version 1.2.0, Shorewall has limited support - for traffic shaping/control. In order to use traffic shaping under Shorewall, - it is essential that you get a copy of the Linux Advanced Routing and Shaping HOWTO, - version 0.3.0 or later. You must also install the iproute (iproute2) package - to provide the "ip" and "tc" utilities.
- + +Beginning with version 1.2.0, Shorewall has limited support + for traffic shaping/control. In order to use traffic shaping under +Shorewall, it is essential that you get a copy of the Linux Advanced Routing and Shaping HOWTO, + version 0.3.0 or later. You must also install the iproute (iproute2) + package to provide the "ip" and "tc" utilities.
+Shorewall traffic shaping support consists of the following:
- +-
-Shorewall allows you to start traffic shaping when Shorewall itself starts -or it allows you to bring up traffic shaping when you bring up your interfaces.- A new TC_ENABLED parameter in /etc/shorewall.conf. -Traffic Shaping also requires that you enable packet mangling.
-- A new CLEAR_TC parameter in /etc/shorewall.conf (Added in Shorewall -1.3.13). When Traffic Shaping is enabled (TC_ENABLED=Yes), the setting of -this variable determines whether Shorewall clears the traffic shaping configuration -during Shorewall [re]start and Shorewall stop.
-
-- /etc/shorewall/tcrules - A file where you can specify - firewall marking of packets. The firewall mark value may be used to -classify packets for traffic shaping/control.
-
-- /etc/shorewall/tcstart - A user-supplied file that -is sourced by Shorewall during "shorewall start" and which you can - use to define your traffic shaping disciplines and classes. I have -provided a sample -that does table-driven CBQ shaping but if you read the traffic shaping -sections of the HOWTO mentioned above, you can probably code your -own faster than you can learn how to use my sample. I personally use - HTB (see below). -HTB support may eventually become an integral part of Shorewall since - HTB is a lot simpler and better-documented than CBQ. As of 2.4.20, -HTB is a standard part of the kernel but iproute2 must be patched in -order to use it.
-
-
- In tcstart, when you want to run the 'tc' utility, use the -run_tc function supplied by shorewall if you want tc errors to stop -the firewall.
-
- You can generally use off-the-shelf traffic shaping scripts by simply -copying them to /etc/shorewall/tcstart. I use The Wonder Shaper (HTB version) - that way (i.e., I just copied wshaper.htb to /etc/shorewall/tcstart and -modified it according to the Wonder Shaper README). WARNING: If you -use use Masquerading or SNAT (i.e., you only have one external IP address) -then listing internal hosts in the NOPRIOHOSTSRC variable in the wshaper[.htb] -script won't work. Traffic shaping occurs after SNAT has already been applied -so when traffic shaping happens, all outbound traffic will have as a source - address the IP addresss of your firewall's external interface.
-- /etc/shorewall/tcclear - A user-supplied file that -is sourced by Shorewall when it is clearing traffic shaping. This -file is normally not required as Shorewall's method of clearing qdisc -and filter definitions is pretty general.
- +- A new TC_ENABLED parameter in /etc/shorewall.conf. + Traffic Shaping also requires that you enable packet mangling.
+- A new CLEAR_TC parameter in /etc/shorewall.conf (Added in +Shorewall 1.3.13). When Traffic Shaping is enabled (TC_ENABLED=Yes), the +setting of this variable determines whether Shorewall clears the traffic +shaping configuration during Shorewall [re]start and Shorewall stop.
+
+- /etc/shorewall/tcrules - A file where you can specify + firewall marking of packets. The firewall mark value may be used + to classify packets for traffic shaping/control.
+
+- /etc/shorewall/tcstart - A user-supplied file that + is sourced by Shorewall during "shorewall start" and which you +can use to define your traffic shaping disciplines and classes. +I have provided a sample that does + table-driven CBQ shaping but if you read the traffic shaping sections +of the HOWTO mentioned above, you can probably code your own faster +than you can learn how to use my sample. I personally use HTB (see below). + HTB support may eventually become an integral part of Shorewall + since HTB is a lot simpler and better-documented than CBQ. As of +2.4.20, HTB is a standard part of the kernel but iproute2 must be patched + in order to use it.
+
+
+ In tcstart, when you want to run the 'tc' utility, use the + run_tc function supplied by shorewall if you want tc errors to stop + the firewall.
+
+ You can generally use off-the-shelf traffic shaping scripts by simply + copying them to /etc/shorewall/tcstart. I use The Wonder Shaper (HTB version) + that way (i.e., I just copied wshaper.htb to /etc/shorewall/tcstart and + modified it according to the Wonder Shaper README). WARNING: If you + use use Masquerading or SNAT (i.e., you only have one external IP address) + then listing internal hosts in the NOPRIOHOSTSRC variable in the wshaper[.htb] + script won't work. Traffic shaping occurs after SNAT has already been applied + so when traffic shaping happens, all outbound traffic will have as a source + address the IP addresss of your firewall's external interface.
+- /etc/shorewall/tcclear - A user-supplied file that + is sourced by Shorewall when it is clearing traffic shaping. This + file is normally not required as Shorewall's method of clearing +qdisc and filter definitions is pretty general.
+
-
-To start traffic shaping when Shorewall starts:
+ Shorewall allows you to start traffic shaping when Shorewall itself starts + or it allows you to bring up traffic shaping when you bring up your interfaces.
+
+ To start traffic shaping when Shorewall starts:
+-
-To start traffic shaping when you bring up your network interfaces, you will -have to arrange for your traffic shaping configuration script to be run at -that time. How you do that is distribution dependent and will not be covered -here. You then should:- Set TC_ENABLED=Yes and CLEAR_TC=Yes
-- Supply an /etc/shorewall/tcstart script to configure your traffic shaping -rules.
-- Optionally supply an /etc/shorewall/tcclear script to stop traffic -shaping. That is usually unnecessary.
-- If your tcstart script uses the 'fwmark' classifier, you can mark packets -using entries in /etc/shorewall/tcrules.
+- Set TC_ENABLED=Yes and CLEAR_TC=Yes
+- Supply an /etc/shorewall/tcstart script to configure your traffic + shaping rules.
+- Optionally supply an /etc/shorewall/tcclear script to stop traffic + shaping. That is usually unnecessary.
+- If your tcstart script uses the 'fwmark' classifier, you can mark + packets using entries in /etc/shorewall/tcrules.
+
+ To start traffic shaping when you bring up your network interfaces, you + will have to arrange for your traffic shaping configuration script to be +run at that time. How you do that is distribution dependent and will not +be covered here. You then should:
+-
- +- Set TC_ENABLED=Yes and CLEAR_TC=No
-- Do not supply /etc/shorewall/tcstart or /etc/shorewall/tcclear scripts.
-- If your tcstart script uses the 'fwmark' classifier, you -can mark packets using entries in /etc/shorewall/tcrules.
+- Set TC_ENABLED=Yes and CLEAR_TC=No
+- Do not supply /etc/shorewall/tcstart or /etc/shorewall/tcclear scripts.
+- If your tcstart script uses the 'fwmark' classifier, you + can mark packets using entries in /etc/shorewall/tcrules.
+Kernel Configuration
- +This screen shot show how I've configured QoS in my Kernel:
- +- + +
-
/etc/shorewall/tcrules
- -The fwmark classifier provides a convenient way to classify - packets for traffic shaping. The /etc/shorewall/tcrules file provides - a means for specifying these marks in a tabular fashion.
- -
-Normally, packet marking occurs in the PREROUTING chain before - any address rewriting takes place. This makes it impossible to mark inbound - packets based on their destination address when SNAT or Masquerading are -being used. Beginning with Shorewall 1.3.12, you can cause packet marking -to occur in the FORWARD chain by using the MARK_IN_FORWARD_CHAIN option in -shorewall.conf.
- -
-Columns in the file are as follows:
- --
- -- MARK - Specifies the mark value is to be assigned in case -of a match. This is an integer in the range 1-255.
-
-
- Example - 5
-- SOURCE - The source of the packet. If the packet originates - on the firewall, place "fw" in this column. Otherwise, this is a - comma-separated list of interface names, IP addresses, MAC addresses in - Shorewall Format and/or Subnets.
-
-
- Examples
- eth0
- 192.168.2.4,192.168.1.0/24
-- DEST -- Destination of the packet. Comma-separated list of - IP addresses and/or subnets.
-
-- PROTO - Protocol - Must be the name of a protocol from - /etc/protocol, a number or "all"
-
-- PORT(S) - Destination Ports. A comma-separated list of Port - names (from /etc/services), port numbers or port ranges (e.g., 21:22); - if the protocol is "icmp", this column is interpreted as the -destination icmp type(s).
-
-- CLIENT PORT(S) - (Optional) Port(s) used by the client. If - omitted, any source port is acceptable. Specified as a comma-separate - list of port names, port numbers or port ranges.
- -Example 1 - All packets arriving on eth1 should be marked - with 1. All packets arriving on eth2 and eth3 should be marked with 2. - All packets originating on the firewall itself should be marked with 3.
- -- -
- -- -MARK -SOURCE -DEST -PROTO -PORT(S) -CLIENT PORT(S) -- -1 -eth1 -0.0.0.0/0 -all -- - - -2 -eth2 -0.0.0.0/0 -all -- - - -2 -
-eth3 -
-0.0.0.0/0 -
-all -
--
--
-- - - -3 -fw -0.0.0.0/0 -all -- - Example 2 - All GRE (protocol 47) packets not originating - on the firewall and destined for 155.186.235.151 should be marked with - 12.
- -- -
- -- -MARK -SOURCE -DEST -PROTO -PORT(S) -CLIENT PORT(S) -- - - -12 -0.0.0.0/0 -155.186.235.151 -47 -- - Example 3 - All SSH packets originating in 192.168.1.0/24 - and destined for 155.186.235.151 should be marked with 22.
- -- -
- -- -MARK -SOURCE -DEST -PROTO -PORT(S) -CLIENT PORT(S) -- - - -22 -192.168.1.0/24 -155.186.235.151 -tcp -22 -- My Setup
- -
-While I am currently using the HTB version of The Wonder Shaper (I just copied - wshaper.htb to /etc/shorewall/tcstart and modified it as shown in -the Wondershaper README), I have also run with the following set of hand-crafted -rules in my /etc/shorewall/tcstart file:
- -
--- -run_tc qdisc add dev eth0 root handle 1: htb default 30- -
run_tc class add dev eth0 parent 1: classid 1:1 htb rate 384kbit burst 15k
echo " Added Top Level Class -- rate 384kbit"run_tc class add dev eth0 parent 1:1 classid 1:10 htb rate 140kbit ceil 384kbit burst 15k prio 1- -
run_tc class add dev eth0 parent 1:1 classid 1:20 htb rate 224kbit ceil 384kbit burst 15k prio 0
run_tc class add dev eth0 parent 1:1 classid 1:30 htb rate 20kbit ceil 384kbit burst 15k quantum 1500 prio 1echo " Added Second Level Classes -- rates 140kbit, 224kbit, 20kbit"- -run_tc qdisc add dev eth0 parent 1:10 pfifo limit 5- -
run_tc qdisc add dev eth0 parent 1:20 pfifo limit 10
run_tc qdisc add dev eth0 parent 1:30 pfifo limit 5echo " Enabled PFIFO on Second Level Classes"- -run_tc filter add dev eth0 protocol ip parent 1:0 prio 1 handle 1 fw classid 1:10- -
run_tc filter add dev eth0 protocol ip parent 1:0 prio 0 handle 2 fw classid 1:20
run_tc filter add dev eth0 protocol ip parent 1:0 prio 1 handle 3 fw classid 1:30echo " Defined fwmark filters"-My tcrules file that went with this tcstart file is shown in Example 1 - above. You can look at my network configuration - to get an idea of why I wanted these particular rules.
+ +The fwmark classifier provides a convenient way to classify + packets for traffic shaping. The /etc/shorewall/tcrules file provides + a means for specifying these marks in a tabular fashion.
+
Normally, packet marking occurs in the PREROUTING chain before + any address rewriting takes place. This makes it impossible to mark inbound + packets based on their destination address when SNAT or Masquerading are + being used. Beginning with Shorewall 1.3.12, you can cause packet marking + to occur in the FORWARD chain by using the MARK_IN_FORWARD_CHAIN option in + shorewall.conf.
+ +
+Columns in the file are as follows:
+ ++
+ +- MARK - Specifies the mark value is to be assigned in case + of a match. This is an integer in the range 1-255. Beginning with +Shorewall version 1.3.14, this value may be optionally followed by ":" and +either 'F' or 'P' to designate that the marking will occur in the FORWARD +or PREROUTING chains respectively. If this additional specification is omitted, +the chain used to mark packets will be determined by the setting of the +MARK_IN_FORWARD_CHAIN option in shorewall.conf.
+
+
+ Example - 5
+- SOURCE - The source of the packet. If the packet originates + on the firewall, place "fw" in this column. Otherwise, this is a + comma-separated list of interface names, IP addresses, MAC addresses +in Shorewall Format and/or Subnets.
+
+
+ Examples
+ eth0
+ 192.168.2.4,192.168.1.0/24
+- DEST -- Destination of the packet. Comma-separated list + of IP addresses and/or subnets.
+
+- PROTO - Protocol - Must be the name of a protocol from + /etc/protocol, a number or "all"
+
+- PORT(S) - Destination Ports. A comma-separated list of +Port names (from /etc/services), port numbers or port ranges (e.g., +21:22); if the protocol is "icmp", this column is interpreted as +the destination icmp type(s).
+
+- CLIENT PORT(S) - (Optional) Port(s) used by the client. + If omitted, any source port is acceptable. Specified as a comma-separate + list of port names, port numbers or port ranges.
+ +Example 1 - All packets arriving on eth1 should be marked + with 1. All packets arriving on eth2 and eth3 should be marked with +2. All packets originating on the firewall itself should be marked with +3.
+ ++ +
+ ++ +MARK +SOURCE +DEST +PROTO +PORT(S) +CLIENT PORT(S) ++ +1 +eth1 +0.0.0.0/0 +all ++ + + +2 +eth2 +0.0.0.0/0 +all ++ + + +2 +
+eth3 +
+0.0.0.0/0 +
+all +
++
++
++ + + +3 +fw +0.0.0.0/0 +all ++ + Example 2 - All GRE (protocol 47) packets not originating + on the firewall and destined for 155.186.235.151 should be marked with + 12.
+ ++ +
+ ++ +MARK +SOURCE +DEST +PROTO +PORT(S) +CLIENT PORT(S) ++ + + +12 +0.0.0.0/0 +155.186.235.151 +47 ++ + Example 3 - All SSH packets originating in 192.168.1.0/24 + and destined for 155.186.235.151 should be marked with 22.
+ ++ +
+ ++ +MARK +SOURCE +DEST +PROTO +PORT(S) +CLIENT PORT(S) ++ + + +22 +192.168.1.0/24 +155.186.235.151 +tcp +22 ++ My Setup
+ +
+While I am currently using the HTB version of The Wonder Shaper (I just copied + wshaper.htb to /etc/shorewall/tcstart and modified it as shown in + the Wondershaper README), I have also run with the following set of hand-crafted + rules in my /etc/shorewall/tcstart file:
+ +
+++ +run_tc qdisc add dev eth0 root handle 1: htb default 30+ +
run_tc class add dev eth0 parent 1: classid 1:1 htb rate 384kbit burst 15k
echo " Added Top Level Class -- rate 384kbit"run_tc class add dev eth0 parent 1:1 classid 1:10 htb rate 140kbit ceil 384kbit burst 15k prio 1+ +
run_tc class add dev eth0 parent 1:1 classid 1:20 htb rate 224kbit ceil 384kbit burst 15k prio 0
run_tc class add dev eth0 parent 1:1 classid 1:30 htb rate 20kbit ceil 384kbit burst 15k quantum 1500 prio 1echo " Added Second Level Classes -- rates 140kbit, 224kbit, 20kbit"+ +run_tc qdisc add dev eth0 parent 1:10 pfifo limit 5+ +
run_tc qdisc add dev eth0 parent 1:20 pfifo limit 10
run_tc qdisc add dev eth0 parent 1:30 pfifo limit 5echo " Enabled PFIFO on Second Level Classes"+ +run_tc filter add dev eth0 protocol ip parent 1:0 prio 1 handle 1 fw classid 1:10+ +
run_tc filter add dev eth0 protocol ip parent 1:0 prio 0 handle 2 fw classid 1:20
run_tc filter add dev eth0 protocol ip parent 1:0 prio 1 handle 3 fw classid 1:30echo " Defined fwmark filters"+My tcrules file that went with this tcstart file is shown in Example 1 + above.
+
+-
- -- I wanted to allow up to 140kbits/second for traffic outbound from - my DMZ (note that the ceiling is set to 384kbit so outbound DMZ traffic -can use all available bandwidth if there is no traffic from the local systems - or from my laptop or firewall).
-- My laptop and local systems could use up to 224kbits/second.
-- My firewall could use up to 20kbits/second.
- +
-- I wanted to allow up to 140kbits/second for traffic outbound + from my DMZ (note that the ceiling is set to 384kbit so outbound DMZ traffic + can use all available bandwidth if there is no traffic from the local systems + or from my laptop or firewall).
+- My laptop and local systems could use up to 224kbits/second.
+- My firewall could use up to 20kbits/second.
+
+Last Updated 12/31/2002 - Tom Eastep
- -Copyright - © 2001, 2002 Thomas M. Eastep.
-
-
+ +Last Updated 2/18/2003 - Tom Eastep
+ +Copyright + © 2001, 2002, 2003 Thomas M. Eastep.
+
diff --git a/Shorewall-docs/troubleshoot.htm b/Shorewall-docs/troubleshoot.htm index cc4d05907..a102f4090 100644 --- a/Shorewall-docs/troubleshoot.htm +++ b/Shorewall-docs/troubleshoot.htm @@ -1,237 +1,232 @@ - +Shorewall Troubleshooting - + - + - +- -
- +- +- + + - - + + + + ++ -Shorewall Troubleshooting
--
Check the Errata
- -Check the Shorewall Errata to be - sure that there isn't an update that you are missing for your version - of the firewall.
- + +Check the Shorewall Errata to be + sure that there isn't an update that you are missing for your version + of the firewall.
+Check the FAQs
- -Check the FAQs for solutions to common - problems.
- + +Check the FAQs for solutions to common + problems.
+If the firewall fails to start
- If you receive an error message when starting or restarting -the firewall and you can't determine the cause, then do the following: - + If you receive an error message when starting or restarting +the firewall and you can't determine the cause, then do the following: +-
- Here's an example. During startup, a user sees the following:- Make a note of the error message that you see.
-
-- shorewall debug start 2> /tmp/trace
-- Look at the /tmp/trace file and see if that helps you - determine what the problem is. Be sure you find the place in the log -where the error message you saw is generated -- in 99.9% of the cases, it -will not be near the end of the log because after startup errors, Shorewall +
- Make a note of the error message that you see.
+
+- shorewall debug start 2> /tmp/trace
+- Look at the /tmp/trace file and see if that helps you + determine what the problem is. Be sure you find the place in the log +where the error message you saw is generated -- in 99.9% of the cases, it +will not be near the end of the log because after startup errors, Shorewall goes through a "shorewall stop" phase which will also be traced.
-- If you still can't determine what's wrong then see the - support page.
- +- If you still can't determine what's wrong then see the + support page.
+
- --- A search through the trace for "No chain/target/match by that name" turned -up the following: -Adding Common Rules-
iptables: No chain/target/match by that name
Terminated-- The command that failed was: "iptables -A reject -p tcp -j REJECT --reject-with -tcp-reset". In this case, the user had compiled his own kernel and had forgotten -to include REJECT target support (see kernel.htm) - -+ echo 'Adding Common Rules'-
+ add_common_rules
+ run_iptables -A reject -p tcp -j REJECT --reject-with tcp-reset
++ echo -A reject -p tcp -j REJECT --reject-with tcp-reset
++ sed 's/!/! /g'
+ iptables -A reject -p tcp -j REJECT --reject-with tcp-reset
iptables: No chain/target/match by that nameYour network environment
- -Many times when people have problems with Shorewall, the problem is -actually an ill-conceived network setup. Here are several popular snafus: -
- --
- -- Port Forwarding where client and server are in -the same subnet. See FAQ 2.
-- Changing the IP address of a local system to be in the external - subnet, thinking that Shorewall will suddenly believe that the system - is in the 'net' zone.
-- Multiple interfaces connected to the same HUB or Switch. -Given the way that the Linux kernel respond to ARP "who-has" requests, -this type of setup does NOT work the way that you expect it to.
- -If you are having connection problems:
- -If the appropriate policy for the connection that you are - trying to make is ACCEPT, please DO NOT ADD ADDITIONAL ACCEPT RULES TRYING - TO MAKE IT WORK. Such additional rules will NEVER make it work, they -add clutter to your rule set and they represent a big security hole in -the event that you forget to remove them later.
- -I also recommend against setting all of your policies to - ACCEPT in an effort to make something work. That robs you of one of - your best diagnostic tools - the "Shorewall" messages that Netfilter - will generate when you try to connect in a way that isn't permitted - by your rule set.
- -Check your log ("/sbin/shorewall show log"). If you don't - see Shorewall messages, then your problem is probably NOT a Shorewall -problem. If you DO see packet messages, it may be an indication that you -are missing one or more rules -- see FAQ 17.
- -While you are troubleshooting, it is a good idea to clear - two variables in /etc/shorewall/shorewall.conf:
- -LOGRATE=""
- -
- LOGBURST=""This way, you will see all of the log messages being - generated (be sure to restart shorewall after clearing these variables).
- -Example:
- + Here's an example. During startup, a user sees the following:
-Jun 27 15:37:56 gateway kernel: - Shorewall:all2all:REJECT:IN=eth2 OUT=eth1 SRC=192.168.2.2 DST=192.168.1.3 - LEN=67 TOS=0x00 PREC=0x00 TTL=63 ID=5805 DF PROTO=UDP SPT=1803 DPT=53 -LEN=47
- -Let's look at the important parts of this message:
- --
- all2all:REJECT - This packet was REJECTed out of the all2all - chain -- the packet was rejected under the "all"->"all" REJECT -policy (see FAQ 17).
-- IN=eth2 - the packet entered the firewall via eth2
-- OUT=eth1 - if accepted, the packet would be sent on eth1
-- SRC=192.168.2.2 - the packet was sent by 192.168.2.2
-- DST=192.168.1.3 - the packet is destined for 192.168.1.3
-- PROTO=UDP - UDP Protocol
-- DPT=53 - DNS
+++ A search through the trace for "No chain/target/match by that name" turned + up the following: +Adding Common Rules+
iptables: No chain/target/match by that name
Terminated++ The command that failed was: "iptables -A reject -p tcp -j REJECT --reject-with + tcp-reset". In this case, the user had compiled his own kernel and had forgotten + to include REJECT target support (see kernel.htm) ++ echo 'Adding Common Rules'+
+ add_common_rules
+ run_iptables -A reject -p tcp -j REJECT --reject-with tcp-reset
++ echo -A reject -p tcp -j REJECT --reject-with tcp-reset
++ sed 's/!/! /g'
+ iptables -A reject -p tcp -j REJECT --reject-with tcp-reset
iptables: No chain/target/match by that nameYour network environment
+ +Many times when people have problems with Shorewall, the problem is + actually an ill-conceived network setup. Here are several popular snafus: +
+ ++
- -- Port Forwarding where client and server are in +the same subnet. See FAQ 2.
+- Changing the IP address of a local system to be in the external + subnet, thinking that Shorewall will suddenly believe that the system + is in the 'net' zone.
+- Multiple interfaces connected to the same HUB or Switch. +Given the way that the Linux kernel respond to ARP "who-has" requests, +this type of setup does NOT work the way that you expect it to.
+In this case, 192.168.2.2 was in the "dmz" zone and 192.168.1.3 - is in the "loc" zone. I was missing the rule:
+ +If you are having connection problems:
+ +If the appropriate policy for the connection that you are + trying to make is ACCEPT, please DO NOT ADD ADDITIONAL ACCEPT RULES TRYING + TO MAKE IT WORK. Such additional rules will NEVER make it work, they add + clutter to your rule set and they represent a big security hole in the +event that you forget to remove them later.
+ +I also recommend against setting all of your policies to + ACCEPT in an effort to make something work. That robs you of one of + your best diagnostic tools - the "Shorewall" messages that Netfilter + will generate when you try to connect in a way that isn't permitted + by your rule set.
+ +Check your log ("/sbin/shorewall show log"). If you don't + see Shorewall messages, then your problem is probably NOT a Shorewall +problem. If you DO see packet messages, it may be an indication that you +are missing one or more rules -- see FAQ 17.
+ +While you are troubleshooting, it is a good idea to clear + two variables in /etc/shorewall/shorewall.conf:
+ +LOGRATE=""
+ +
+ LOGBURST=""This way, you will see all of the log messages being + generated (be sure to restart shorewall after clearing these variables).
+ +Example:
+ + +Jun 27 15:37:56 gateway kernel: + Shorewall:all2all:REJECT:IN=eth2 OUT=eth1 SRC=192.168.2.2 DST=192.168.1.3 + LEN=67 TOS=0x00 PREC=0x00 TTL=63 ID=5805 DF PROTO=UDP SPT=1803 DPT=53 + LEN=47
+ +Let's look at the important parts of this message:
++
+ +- all2all:REJECT - This packet was REJECTed out of the all2all + chain -- the packet was rejected under the "all"->"all" REJECT policy + (see FAQ 17).
+- IN=eth2 - the packet entered the firewall via eth2
+- OUT=eth1 - if accepted, the packet would be sent on eth1
+- SRC=192.168.2.2 - the packet was sent by 192.168.2.2
+- DST=192.168.1.3 - the packet is destined for 192.168.1.3
+- PROTO=UDP - UDP Protocol
+- DPT=53 - DNS
+ +In this case, 192.168.2.2 was in the "dmz" zone and 192.168.1.3 + is in the "loc" zone. I was missing the rule:
+ACCEPT dmz loc udp 53
- -
-See FAQ 17 for additional information +
+ +See FAQ 17 for additional information about how to interpret the chain name appearing in a Shorewall log message.
- + +
-'Ping' Problems?
-Either can't ping when you think you should be able to or are able to ping + Either can't ping when you think you should be able to or are able to ping when you think that you shouldn't be allowed? Shorewall's 'Ping' Management is described here.
+Other Gotchas
- +-
- +- Seeing rejected/dropped packets logged out of the INPUT or - FORWARD chains? This means that: - +
- Seeing rejected/dropped packets logged out of the INPUT +or FORWARD chains? This means that: +
--
-- your zone definitions are screwed up and the host that -is sending the packets or the destination host isn't in any zone -(using an /etc/shorewall/hosts +
- your zone definitions are screwed up and the host that +is sending the packets or the destination host isn't in any zone +(using an /etc/shorewall/hosts file are you?); or
-- the source and destination hosts are both connected to -the same interface and that interface doesn't have the 'multi' -option specified in /etc/shorewall/interfaces.
- +- the source and destination hosts are both connected to +the same interface and you don't have a policy or rule for the +source zone to or from the destination zone.
+- Remember that Shorewall doesn't automatically allow ICMP - type 8 ("ping") requests to be sent between zones. If you want pings +
+- Remember that Shorewall doesn't automatically allow ICMP + type 8 ("ping") requests to be sent between zones. If you want pings to be allowed between zones, you need a rule of the form:
-
-
- ACCEPT <source zone> <destination zone> +
+ ACCEPT <source zone> <destination zone> icmp echo-request
-
- The ramifications of this can be subtle. For example, if you -have the following in /etc/shorewall/nat:
-
- 10.1.1.2 eth0 130.252.100.18
-
- and you ping 130.252.100.18, unless you have allowed icmp type - 8 between the zone containing the system you are pinging from and the - zone containing 10.1.1.2, the ping requests will be dropped. This is - true even if you have NOT specified 'noping' for eth0 in /etc/shorewall/interfaces.- If you specify "routefilter" for an interface, that interface - must be up prior to starting the firewall.
-- Is your routing correct? For example, internal systems usually - need to be configured with their default gateway set to the IP address - of their nearest firewall interface. One often overlooked aspect -of routing is that in order for two hosts to communicate, the routing -between them must be set up in both directions. So when setting -up routing between A and B, be sure to verify that the +
+
+ The ramifications of this can be subtle. For example, if you + have the following in /etc/shorewall/nat:
+
+ 10.1.1.2 eth0 130.252.100.18
+
+ and you ping 130.252.100.18, unless you have allowed icmp type + 8 between the zone containing the system you are pinging from and +the zone containing 10.1.1.2, the ping requests will be dropped.- If you specify "routefilter" for an interface, that +interface must be up prior to starting the firewall.
+- Is your routing correct? For example, internal systems usually + need to be configured with their default gateway set to the IP address + of their nearest firewall interface. One often overlooked aspect of + routing is that in order for two hosts to communicate, the routing +between them must be set up in both directions. So when setting +up routing between A and B, be sure to verify that the route from B back to A is defined.
-- Some versions of LRP (EigerStein2Beta for example) have a - shell with broken variable expansion. You can get a corrected - shell from the Shorewall Errata download site.
-- Do you have your kernel properly configured? Some versions of LRP (EigerStein2Beta for example) have +a shell with broken variable expansion. You can get a corrected + shell from the Shorewall Errata download site.
+- Do you have your kernel properly configured? Click here to see my kernel configuration.
-- Some features require the "ip" program. That program -is generally included in the "iproute" package which should be included - with your distribution (though many distributions don't install iproute - by default). You may also download the latest source tarball from ftp://ftp.inr.ac.ru/ip-routing +
- Some features require the "ip" program. That program +is generally included in the "iproute" package which should be included + with your distribution (though many distributions don't install iproute + by default). You may also download the latest source tarball from ftp://ftp.inr.ac.ru/ip-routing .
-- If you have any entry for a zone in /etc/shorewall/hosts - then the zone must be entirely defined in /etc/shorewall/hosts unless - you have specified MERGE_HOSTS=Yes (Shorewall version 1.3.5 and later). - For example, if a zone has two interfaces but only one interface has an - entry in /etc/shorewall/hosts then hosts attached to the other interface - will not be considered part of the zone.
-- Problems with NAT? Be sure that you let Shorewall add all - external addresses to be use with NAT unless you have set Problems with NAT? Be sure that you let Shorewall +add all external addresses to be use with NAT unless you have set ADD_IP_ALIASES =No in /etc/shorewall/shorewall.conf.
- +Still Having Problems?
- +See the support page.
- - + + +
-- -Last updated 1/7/2003 - Tom Eastep
- -Copyright - © 2001, 2002 Thomas M. Eastep.
+ +
-Last updated 2/18/2003 - Tom Eastep
+ +Copyright + © 2001, 2002 Thomas M. Eastep.
+
+
diff --git a/Shorewall-docs/two-interface.htm b/Shorewall-docs/two-interface.htm index ef83fa92d..d6ebaeaff 100644 --- a/Shorewall-docs/two-interface.htm +++ b/Shorewall-docs/two-interface.htm @@ -1,713 +1,534 @@ - + - + - + - +Two-Interface Firewall - + - +- -
- +- +- + + - - + + + ++ + -Basic Two-Interface Firewall
-Setting up a Linux system as a firewall for a small network - is a fairly straight-forward task if you understand the basics and -follow the documentation.
- + is a fairly straight-forward task if you understand the basics and + follow the documentation. +This guide doesn't attempt to acquaint you with all of the features of - Shorewall. It rather focuses on what is required to configure Shorewall - in its most common configuration:
- + Shorewall. It rather focuses on what is required to configure Shorewall + in its most common configuration: +-
- +- Linux system used as a firewall/router for a small local - network.
-- Single public IP address.
-- Internet connection through cable modem, DSL, ISDN, Frame - Relay, dial-up ...
- +- Linux system used as a firewall/router for a small +local network.
+- Single public IP address.
+- Internet connection through cable modem, DSL, ISDN, +Frame Relay, dial-up ...
+Here is a schematic of a typical installation.
- +- + +
-
If you are running Shorewall under Mandrake 9.0 or later, you can easily - configure the above setup using the Mandrake "Internet Connection Sharing" - applet. From the Mandrake Control Center, select "Network & Internet" - then "Connection Sharing". You should not need to refer to this guide.
- + configure the above setup using the Mandrake "Internet Connection Sharing" + applet. From the Mandrake Control Center, select "Network & Internet" + then "Connection Sharing".
-
+ +Note however, that the Shorewall configuration produced by Mandrake +Internet Connection Sharing is strange and is apt to confuse you if you use +the rest of this documentation (it has two local zones; "loc" and "masq" +where "loc" is empty; this conflicts with this documentation which assumes +a single local zone "loc"). We therefore recommend that once you have set +up this sharing that you uninstall the Mandrake Shorewall RPM and install +the one from the download page then follow the +instructions in this Guide.
+
+This guide assumes that you have the iproute/iproute2 package installed - (on RedHat, the package is called iproute). You can tell - if this package is installed by the presence of an ip program - on your firewall system. As root, you can use the 'which' command to -check for this program:
- + (on RedHat, the package is called iproute). You can +tell if this package is installed by the presence of an ip program + on your firewall system. As root, you can use the 'which' command to + check for this program: +[root@gateway root]# which ip- +
/sbin/ip
[root@gateway root]#I recommend that you first read through the guide to familiarize yourself - with what's involved then go back through it again making your configuration - changes. Points at which configuration changes are recommended are -flagged with
- + +- . Configuration notes that are unique to LEAF/Bering are marked -with
-
- + If you edit your configuration files on a Windows system, + you must save them as Unix files if your editor supports that option + or you must run them through dos2unix before trying to use them. Similarly, + if you copy a configuration file from your Windows hard drive to a floppy + disk, you must run dos2unix against the copy before using it with Shorewall. + - +
- If you edit your configuration files on a Windows system, - you must save them as Unix files if your editor supports that option - or you must run them through dos2unix before trying to use them. Similarly, - if you copy a configuration file from your Windows hard drive to a floppy - disk, you must run dos2unix against the copy before using it with Shorewall.
Shorewall Concepts
- +- + un-tar it (tar -zxvf two-interfaces.tgz) and and copy the files to +/etc/shorewall (these files will replace files with the same name). +
- The configuration files for Shorewall are contained in the directory - /etc/shorewall -- for simple setups, you will only need to deal with + The configuration files for Shorewall are contained in the directory + /etc/shorewall -- for simple setups, you will only need to deal with a few of these as described in this guide. After you have installed Shorewall, download the two-interface sample, - un-tar it (tar -zxvf two-interfaces.tgz) and and copy the files to /etc/shorewall - (these files will replace files with the same name).
As each file is introduced, I suggest that you look through the actual - file on your system -- each file contains detailed configuration instructions - and default entries.
- + file on your system -- each file contains detailed configuration instructions + and default entries. +Shorewall views the network where it is running as being composed of a - set of zones. In the two-interface sample configuration, the - following zone names are used:
- + set of zones. In the two-interface sample configuration, the + following zone names are used: +- -
- +- -Name -Description -- -net -The Internet -- - - + +loc -Your Local Network -+ +Name +Description ++ +net +The Internet ++ + +loc +Your Local Network +Zones are defined in the /etc/shorewall/zones - file.
- + file. +Shorewall also recognizes the firewall system as its own zone - by default, - the firewall itself is known as fw.
- + the firewall itself is known as fw. +Rules about what traffic to allow and what traffic to deny are expressed - in terms of zones.
- + in terms of zones. +-
- +- You express your default policy for connections from -one zone to another zone in theYou express your default policy for connections from + one zone to another zone in the /etc/shorewall/policy file.
-- You define exceptions to those default policies in the - /etc/shorewall/rules file.
- +- You define exceptions to those default policies in +the /etc/shorewall/rules file.
+For each connection request entering the firewall, the request is first - checked against the /etc/shorewall/rules file. If no rule in that file - matches the connection request then the first policy in /etc/shorewall/policy - that matches the request is applied. If that policy is REJECT or DROP - the request is first checked against the rules in /etc/shorewall/common - (the samples provide that file for you).
- + checked against the /etc/shorewall/rules file. If no rule in that +file matches the connection request then the first policy in /etc/shorewall/policy + that matches the request is applied. If that policy is REJECT or +DROP the request is first checked against the rules in /etc/shorewall/common + (the samples provide that file for you). +The /etc/shorewall/policy file included with the two-interface sample has the following policies:
- -+ ++- -- -
-- -Source Zone -Destination Zone -Policy -Log Level -Limit:Burst -- -loc -net -ACCEPT -- - - -net -all -DROP -info -- - + +all -all -REJECT -info -- + +Source Zone +Destination Zone +Policy +Log Level +Limit:Burst ++ +loc +net +ACCEPT ++ + + +net +all +DROP +info ++ + - - + +all +all +REJECT +info ++ ++ +- +In the two-interface sample, the line below is included but commented - out. If you want your firewall system to have full access to servers - on the internet, uncomment that line.
- + out. If you want your firewall system to have full access to servers + on the internet, uncomment that line. +- -
-- -Source Zone -Destination Zone -Policy -Log Level -Limit:Burst -- + +fw -net -ACCEPT -- - + +Source Zone +Destination Zone +Policy +Log Level +Limit:Burst ++ - - + +fw +net +ACCEPT ++ + The above policy will:
- +-
- +- allow all connection requests from your local network -to the internet
-- drop (ignore) all connection requests from the internet - to your firewall or local network
-- optionally accept all connection requests from the firewall - to the internet (if you uncomment the additional policy)
-- reject all other connection requests.
- +- allow all connection requests from your local network + to the internet
+- drop (ignore) all connection requests from the internet + to your firewall or local network
+- optionally accept all connection requests from the +firewall to the internet (if you uncomment the additional policy)
+- reject all other connection requests.
+- + At this point, edit your /etc/shorewall/policy and make + any changes that you wish. +
- At this point, edit your /etc/shorewall/policy and make -any changes that you wish.
Network Interfaces
- +- + +
-
The firewall has two network interfaces. Where Internet connectivity is through a cable or DSL "Modem", the External Interface will be the ethernet adapter that is connected to that "Modem" (e.g., eth0) - unless you connect via Point-to-Point Protocol - over Ethernet (PPPoE) or Point-to-Point - Tunneling Protocol (PPTP) in which case the External - Interface will be a ppp interface (e.g., ppp0). If you connect -via a regular modem, your External Interface will also be ppp0. -If you connect via ISDN, your external interface will be ippp0.
- + unless you connect via Point-to-Point Protocol + over Ethernet (PPPoE) or Point-to-Point + Tunneling Protocol (PPTP) in which case the External + Interface will be a ppp interface (e.g., ppp0). If you connect + via a regular modem, your External Interface will also be ppp0. + If you connect via ISDN, your external interface will be ippp0. +- +
- If your external interface is ppp0 or ippp0 - then you will want to set CLAMPMSS=yes in ppp0 or ippp0 + then you will want to set CLAMPMSS=yes in /etc/shorewall/shorewall.conf.
Your Internal Interface will be an ethernet adapter - (eth1 or eth0) and will be connected to a hub or switch. Your other - computers will be connected to the same hub/switch (note: If you have - only a single internal system, you can connect the firewall directly - to the computer using a cross-over cable).
- + (eth1 or eth0) and will be connected to a hub or switch. Your other + computers will be connected to the same hub/switch (note: If you have + only a single internal system, you can connect the firewall directly + to the computer using a cross-over cable). +- + Do not connect the internal and external interface + to the same hub or switch (even for testing). It won't work the way + that you think that it will and you will end up confused and believing + that Shorewall doesn't work at all. +
- Do not connect the internal and external interface -to the same hub or switch (even for testing). It won't work the way -that you think that it will and you will end up confused and believing -that Shorewall doesn't work at all.
- + The Shorewall two-interface sample configuration assumes + that the external interface is eth0 and the internal interface + is eth1. If your configuration is different, you will have to + modify the sample /etc/shorewall/interfaces + file accordingly. While you are there, you may wish to review the +list of options that are specified for the interfaces. Some hints: +
- The Shorewall two-interface sample configuration assumes -that the external interface is eth0 and the internal interface -is eth1. If your configuration is different, you will have to -modify the sample /etc/shorewall/interfaces - file accordingly. While you are there, you may wish to review the list - of options that are specified for the interfaces. Some hints:
-
- +- - +
- +
-If your external interface is ppp0 or ippp0, - you can replace the "detect" in the second column with "-".
-- - + you can replace the "detect" in the second column with "-". +
+- +
- + or if you have a static IP address, you can remove "dhcp" from the + option list. + +If your external interface is ppp0 or ippp0 - or if you have a static IP address, you can remove "dhcp" from the - option list.
-IP Addresses
- +Before going further, we should say a few words about Internet - Protocol (IP) addresses. Normally, your ISP will assign you -a single Public IP address. This address may be assigned via the - Dynamic Host Configuration Protocol (DHCP) or as part of establishing + Protocol (IP) addresses. Normally, your ISP will assign you + a single Public IP address. This address may be assigned via +the Dynamic Host Configuration Protocol (DHCP) or as part of establishing your connection when you dial in (standard modem) or establish your PPP connection. In rare cases, your ISP may assign you a static IP address; that means that you configure your firewall's external interface - to use that address permanently. However your external address is - assigned, it will be shared by all of your systems when you access the -Internet. You will have to assign your own addresses in your internal network + to use that address permanently. However your external address +is assigned, it will be shared by all of your systems when you access the + Internet. You will have to assign your own addresses in your internal network (the Internal Interface on your firewall plus your other computers). RFC 1918 reserves several Private IP address ranges for this purpose:
- -+ ++- -10.0.0.0 - 10.255.255.255-
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255++ +- --
- Before starting Shorewall, you should look at the IP -address of your external interface and if it is one of the above -ranges, you should remove the 'norfc1918' option from the external -interface's entry in /etc/shorewall/interfaces.
+ Before starting Shorewall, you should look at the IP + address of your external interface and if it is one of the above + ranges, you should remove the 'norfc1918' option from the external + interface's entry in /etc/shorewall/interfaces. ++ +- -You will want to assign your addresses from the same sub-network (subnet). For our purposes, we can consider a subnet - to consists of a range of addresses x.y.z.0 - x.y.z.255. Such a subnet - will have a Subnet Mask of 255.255.255.0. The address x.y.z.0 - is reserved as the Subnet Address and x.y.z.255 is reserved - as the Subnet Broadcast Address. In Shorewall, a subnet - is described using Classless - InterDomain Routing (CIDR) notation with consists of the subnet - address followed by "/24". The "24" refers to the number of consecutive - leading "1" bits from the left of the subnet mask.
-+ to consists of a range of addresses x.y.z.0 - x.y.z.255. Such a +subnet will have a Subnet Mask of 255.255.255.0. The address +x.y.z.0 is reserved as the Subnet Address and x.y.z.255 is +reserved as the Subnet Broadcast Address. In Shorewall, +a subnet is described using Classless InterDomain Routing + (CIDR) notation with consists of the subnet address followed + by "/24". The "24" refers to the number of consecutive leading "1" bits +from the left of the subnet mask. ++ +- -Example sub-network:
--+ +++- --- -
-- -Range: -10.10.10.0 - 10.10.10.255 -- -Subnet Address: -10.10.10.0 -- -Broadcast Address: -10.10.10.255 -- + +CIDR Notation: -10.10.10.0/24 -+ +Range: +10.10.10.0 - 10.10.10.255 ++ +Subnet Address: +10.10.10.0 ++ +Broadcast Address: +10.10.10.255 ++ - - + +CIDR Notation: +10.10.10.0/24 ++ ++ +- -It is conventional to assign the internal interface either - the first usable address in the subnet (10.10.10.1 in the above example) - or the last usable address (10.10.10.254).
-+ the first usable address in the subnet (10.10.10.1 in the above +example) or the last usable address (10.10.10.254). ++ +- -One of the purposes of subnetting is to allow all computers - in the subnet to understand which other computers can be communicated - with directly. To communicate with systems outside of the subnetwork, - systems send packets through a gateway (router).
-+ in the subnet to understand which other computers can be communicated + with directly. To communicate with systems outside of the subnetwork, + systems send packets through a gateway (router). ++ +- + Your local computers (computer 1 and computer 2 in +the above diagram) should be configured with their default gateway + to be the IP address of the firewall's internal interface. + +-
- Your local computers (computer 1 and computer 2 in the - above diagram) should be configured with their default gateway - to be the IP address of the firewall's internal interface. -
The foregoing short discussion barely scratches the surface - regarding subnetting and routing. If you are interested in learning - more about IP addressing and routing, I highly recommend "IP Fundamentals: - What Everyone Needs to Know about Addressing & Routing", Thomas - A. Maufer, Prentice-Hall, 1999, ISBN 0-13-975483-0.
- + regarding subnetting and routing. If you are interested in learning + more about IP addressing and routing, I highly recommend "IP Fundamentals: + What Everyone Needs to Know about Addressing & Routing", Thomas + A. Maufer, Prentice-Hall, 1999, ISBN 0-13-975483-0. +The remainder of this quide will assume that you have configured - your network as shown here:
- + your network as shown here: +- + +
-
The default gateway for computer's 1 & 2 would be 10.10.10.254.
- + +
-- + WARNING: Your ISP might assign + your external interface an RFC 1918 address. If that address is in the 10.10.10.0/24 + subnet then you will need to select a DIFFERENT RFC 1918 subnet for your +local network.
- WARNING: Your ISP might assign -your external interface an RFC 1918 address. If that address is in the 10.10.10.0/24 -subnet then you will need to select a DIFFERENT RFC 1918 subnet for your local -network.
-
+ +IP Masquerading (SNAT)
- +The addresses reserved by RFC 1918 are sometimes referred - to as non-routable because the Internet backbone routers don't - forward packets which have an RFC-1918 destination address. When one - of your local systems (let's assume computer 1) sends a connection request - to an internet host, the firewall must perform Network Address Translation - (NAT). The firewall rewrites the source address in the packet to - be the address of the firewall's external interface; in other words, - the firewall makes it look as if the firewall itself is initiating the - connection. This is necessary so that the destination host will be able - to route return packets back to the firewall (remember that packets whose - destination address is reserved by RFC 1918 can't be routed across the - internet so the remote host can't address its response to computer 1). -When the firewall receives a return packet, it rewrites the destination address - back to 10.10.10.1 and forwards the packet on to computer 1.
- + to as non-routable because the Internet backbone routers don't + forward packets which have an RFC-1918 destination address. When one + of your local systems (let's assume computer 1) sends a connection request + to an internet host, the firewall must perform Network Address +Translation (NAT). The firewall rewrites the source address in +the packet to be the address of the firewall's external interface; in +other words, the firewall makes it look as if the firewall itself is +initiating the connection. This is necessary so that the destination +host will be able to route return packets back to the firewall (remember +that packets whose destination address is reserved by RFC 1918 can't +be routed across the internet so the remote host can't address its response +to computer 1). When the firewall receives a return packet, it rewrites +the destination address back to 10.10.10.1 and forwards the packet on to +computer 1. +On Linux systems, the above process is often referred to as IP Masquerading but you will also see the term Source Network Address Translation (SNAT) used. Shorewall follows the convention used with Netfilter:
- +-
- +- - +
- +
-Masquerade describes the case where you let your - firewall system automatically detect the external interface address. -
-- - + firewall system automatically detect the external interface address. + +
+- +
- + the source address that you want outbound packets from your local + network to use. + +SNAT refers to the case when you explicitly specify - the source address that you want outbound packets from your local - network to use.
-In Shorewall, both Masquerading and SNAT are configured with - entries in the /etc/shorewall/masq file. You will normally use Masquerading - if your external IP is dynamic and SNAT if the IP is static.
- + entries in the /etc/shorewall/masq file. You will normally use Masquerading + if your external IP is dynamic and SNAT if the IP is static. +- + If your external firewall interface is eth0, you + do not need to modify the file provided with the sample. Otherwise, + edit /etc/shorewall/masq and change the first column to the name +of your external interface and the second column to the name of your +internal interface. +
- If your external firewall interface is eth0, you -do not need to modify the file provided with the sample. Otherwise, -edit /etc/shorewall/masq and change the first column to the name of -your external interface and the second column to the name of your internal - interface.
- + If you are using the Debian package, please check your shorewall.conf + file to ensure that the following are set correctly; if they are not, change + them appropriately:
- If your external IP is static, you can enter it in the -third column in the /etc/shorewall/masq entry if you like although -your firewall will work fine if you leave that column empty. Entering -your static IP in column 3 makes processing outgoing packets a little - more efficient.
-
-+
+- If you are using the Debian package, please check your shorewall.conf - file to ensure that the following are set correctly; if they are not, change - them appropriately:
-
+ +-
- +- NAT_ENABLED=Yes
-- IP_FORWARDING=On
- +
-- NAT_ENABLED=Yes
+- IP_FORWARDING=On
+
+Port Forwarding (DNAT)
- +One of your goals may be to run one or more servers on your - local computers. Because these computers have RFC-1918 addresses, it - is not possible for clients on the internet to connect directly to them. - It is rather necessary for those clients to address their connection -requests to the firewall who rewrites the destination address to the -address of your server and forwards the packet to that server. When your -server responds, the firewall automatically performs SNAT to rewrite -the source address in the response.
- + local computers. Because these computers have RFC-1918 addresses, +it is not possible for clients on the internet to connect directly to +them. It is rather necessary for those clients to address their connection + requests to the firewall who rewrites the destination address to the + address of your server and forwards the packet to that server. When +your server responds, the firewall automatically performs SNAT to rewrite + the source address in the response. +The above process is called Port Forwarding or - Destination Network Address Translation (DNAT). You configure + Destination Network Address Translation (DNAT). You configure port forwarding using DNAT rules in the /etc/shorewall/rules file.
- +The general form of a simple port forwarding rule in /etc/shorewall/rules - is:
- --- -- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -SOURCE PORT -ORIGINAL ADDRESS -- - - - -DNAT -net -loc:<server local ip address> [:<server - port>] -<protocol> -<port> -- - Example - you run a Web Server on computer 2 and you want to forward incoming - TCP port 80 to that system:
- --- -- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -SOURCE PORT -ORIGINAL ADDRESS -- - - - -DNAT -net -loc:10.10.10.2 -tcp -80 -- - A couple of important points to keep in mind:
- --
- -- You must test the above rule from a client outside of -your local network (i.e., don't test from a browser running on computers - 1 or 2 or on the firewall). If you want to be able to access your -web server using the IP address of your external interface, see Shorewall FAQ #2.
-- Many ISPs block incoming connection requests to port -80. If you have problems connecting to your web server, try the -following rule and try connecting to port 5000.
- --- -- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -SOURCE PORT -ORIGINAL ADDRESS -- - - - -DNAT -net -loc:10.10.10.2:80 -tcp -5000 -- - - -
- At this point, modify /etc/shorewall/rules to add any DNAT - rules that you require.
Domain Name Server (DNS)
- -Normally, when you connect to your ISP, as part of getting - an IP address your firewall's Domain Name Service (DNS) resolver - will be automatically configured (e.g., the /etc/resolv.conf file will - be written). Alternatively, your ISP may have given you the IP address - of a pair of DNS name servers for you to manually configure as -your primary and secondary name servers. Regardless of how DNS gets configured - on your firewall, it is your responsibility to configure the resolver - in your internal systems. You can take one of two approaches:
- --
- -- - -
-You can configure your internal systems to use your ISP's - name servers. If you ISP gave you the addresses of their servers -or if those addresses are available on their web site, you can configure - your internal systems to use those addresses. If that information -isn't available, look in /etc/resolv.conf on your firewall system -- -the name servers are given in "nameserver" records in that file.
-- - -
- --
- You can configure a Caching Name Server on your - firewall. Red Hat has an RPM for a caching name server -(the RPM also requires the 'bind' RPM) and for Bering users, there -is dnscache.lrp. If you take this approach, you configure your internal -systems to use the firewall itself as their primary (and only) name server. -You use the internal IP address of the firewall (10.10.10.254 in the -example above) for the name server address. To allow your local systems -to talk to your caching name server, you must open port 53 (both UDP -and TCP) from the local network to the firewall; you do that by adding -the following rules in /etc/shorewall/rules.
-- -- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -SOURCE PORT -ORIGINAL ADDRESS -- -ACCEPT -loc -fw -tcp -53 -- - - - - - -ACCEPT -loc -fw -udp -53 -- - -- -Other Connections
--- -The two-interface sample includes the following rules:
--- -+ is: + +--
-+ ACTION SOURCE DESTINATION @@ -717,325 +538,507 @@ the following rules in /etc/shorewall/rules.ORIGINAL ADDRESS - -ACCEPT -fw +DNAT net -tcp -53 -- - - - - - -ACCEPT -fw -net -udp -53 -- - -- -Those rules allow DNS access from your firewall and may be - removed if you uncommented the line in /etc/shorewall/policy allowing - all connections from the firewall to the internet.
--- -The sample also includes:
--- ---- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -SOURCE PORT -ORIGINAL ADDRESS -- - - - -ACCEPT -loc -fw -tcp -22 -- - -- -That rule allows you to run an SSH server on your firewall - and connect to that server from your local systems.
--- -If you wish to enable other connections between your firewall - and other systems, the general format is:
--+ +--- -
- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -SOURCE PORT -ORIGINAL ADDRESS -- - - + +ACCEPT -<source zone> -<destination zone> +loc:<server local ip address> [:<server + port>] <protocol> <port> Example - you run a Web Server on computer 2 and you want to forward incoming + TCP port 80 to that system:
+ +++ ++ +
++ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +SOURCE PORT +ORIGINAL ADDRESS ++ + + + +DNAT +net +loc:10.10.10.2 +tcp +80 ++ + A couple of important points to keep in mind:
+ ++
+ +- You must test the above rule from a client outside +of your local network (i.e., don't test from a browser running on +computers 1 or 2 or on the firewall). If you want to be able to +access your web server using the IP address of your external interface, +see Shorewall FAQ #2.
+- Many ISPs block incoming connection requests to port + 80. If you have problems connecting to your web server, try the +following rule and try connecting to port 5000.
+ +++ ++ +
++ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +SOURCE PORT +ORIGINAL ADDRESS ++ + + + +DNAT +net +loc:10.10.10.2:80 +tcp +5000 ++ + + +
+ At this point, modify /etc/shorewall/rules to add any +DNAT rules that you require.
Domain Name Server (DNS)
+ +Normally, when you connect to your ISP, as part of getting + an IP address your firewall's Domain Name Service (DNS) resolver + will be automatically configured (e.g., the /etc/resolv.conf file will + be written). Alternatively, your ISP may have given you the IP address + of a pair of DNS name servers for you to manually configure as + your primary and secondary name servers. Regardless of how DNS gets +configured on your firewall, it is your responsibility to configure +the resolver in your internal systems. You can take one of two approaches:
+ ++
- -
+You can configure your internal systems to use your ISP's + name servers. If you ISP gave you the addresses of their servers + or if those addresses are available on their web site, you can configure + your internal systems to use those addresses. If that information + isn't available, look in /etc/resolv.conf on your firewall system +-- the name servers are given in "nameserver" records in that file. +
+ +- + +
+ + + ++
+ You can configure a Caching Name Server on your + firewall. Red Hat has an RPM for a caching name server + (the RPM also requires the 'bind' RPM) and for Bering users, there + is dnscache.lrp. If you take this approach, you configure your internal + systems to use the firewall itself as their primary (and only) name +server. You use the internal IP address of the firewall (10.10.10.254 +in the example above) for the name server address. To allow your +local systems to talk to your caching name server, you must open port +53 (both UDP and TCP) from the local network to the firewall; you +do that by adding the following rules in /etc/shorewall/rules.
++ ++ +
++ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +SOURCE PORT +ORIGINAL ADDRESS ++ +ACCEPT +loc +fw +tcp +53 ++ + + + + + +ACCEPT +loc +fw +udp +53 ++ + ++ +Other Connections
+++ +The two-interface sample includes the following rules:
+++ ++++ +
++ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +SOURCE PORT +ORIGINAL ADDRESS ++ +ACCEPT +fw +net +tcp +53 ++ + + + + + +ACCEPT +fw +net +udp +53 ++ + ++ +Those rules allow DNS access from your firewall and may be + removed if you uncommented the line in /etc/shorewall/policy allowing + all connections from the firewall to the internet.
+++ +The sample also includes:
+++ ++++ +
++ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +SOURCE PORT +ORIGINAL ADDRESS ++ + + + +ACCEPT +loc +fw +tcp +22 ++ + ++ +That rule allows you to run an SSH server on your firewall + and connect to that server from your local systems.
+++ +If you wish to enable other connections between your firewall + and other systems, the general format is:
+++ ++++ +
++ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +SOURCE PORT +ORIGINAL ADDRESS ++ + + + +ACCEPT +<source zone> +<destination zone> +<protocol> +<port> ++ + - -Example - You want to run a Web Server on your firewall system:
--+ +++- --- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -SOURCE PORT -ORIGINAL ADDRESS -- -ACCEPT -net -fw -tcp -80 -#Allow web access -from the internet -- + +ACCEPT -loc -fw -tcp -80 -#Allow web access -from the local network -+ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +SOURCE PORT +ORIGINAL ADDRESS ++ +ACCEPT +net +fw +tcp +80 +#Allow web access +from the internet ++ - - + +ACCEPT +loc +fw +tcp +80 +#Allow web access +from the local network ++ ++ +- -Those two rules would of course be in addition to the rules - listed above under "You can configure a Caching Name Server on your - firewall"
-+ listed above under "You can configure a Caching Name Server on your + firewall" ++ +- -If you don't know what port and protocol a particular application uses, look here.
-++ +- -Important: I don't recommend enabling telnet to/from - the internet because it uses clear text (even for login!). If you - want shell access to your firewall from the internet, use SSH:
--+ ++ the internet because it uses clear text (even for login!). If you + want shell access to your firewall from the internet, use SSH: ++- --- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -SOURCE PORT -ORIGINAL ADDRESS -- + +ACCEPT -net -fw -tcp -22 -- - + +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +SOURCE PORT +ORIGINAL ADDRESS ++ - - + +ACCEPT +net +fw +tcp +22 ++ + + ++ +- --
- Bering users will want to add the following two rules to be compatible -with Jacques's Shorewall configuration.
-++ Bering users will want to add the following two rules to be compatible + with Jacques's Shorewall configuration. + ++++-- -
-- -ACTION -SOURCE -DESTINATION -PROTOCOL -PORT -SOURCE PORT -ORIGINAL ADDRESS -- -ACCEPT -loc -
-fw -udp -
-53 -
-#Allow DNS Cache to -work -
-- + +ACCEPT -loc -fw -tcp -80 -#Allow weblet to work --
-+ +ACTION +SOURCE +DESTINATION +PROTOCOL +PORT +SOURCE PORT +ORIGINAL ADDRESS ++ +ACCEPT +loc +
+fw +udp +
+53 +
+#Allow DNS Cache to +work +
++ - - + +ACCEPT +loc +fw +tcp +80 +#Allow weblet to work ++
+-
-- Now edit your /etc/shorewall/rules file to add or delete - other connections as required.
++ ++ Now edit your /etc/shorewall/rules file to add or delete + other connections as required. +
- -Starting and Stopping Your Firewall
-++ +- -- + The installation procedure + configures your system to start Shorewall at system boot but beginning +with Shorewall version 1.3.9 startup is disabled so that your system +won't try to start Shorewall before configuration is complete. Once you +have completed configuration of your firewall, you can enable Shorewall +startup by removing the file /etc/shorewall/startup_disabled.
- The installation procedure configures - your system to start Shorewall at system boot but beginning with Shorewall - version 1.3.9 startup is disabled so that your system won't try to start - Shorewall before configuration is complete. Once you have completed configuration - of your firewall, you can enable Shorewall startup by removing the file - /etc/shorewall/startup_disabled.
-
+ +IMPORTANT: Users of the .deb package must edit /etc/default/shorewall - and set 'startup=1'.
-
-+ and set 'startup=1'.+ +
+ +- -The firewall is started using the "shorewall start" command - and stopped using "shorewall stop". When the firewall is stopped, - routing is enabled on those hosts that have an entry in /etc/shorewall/routestopped. A - running firewall may be restarted using the "shorewall restart" command. - If you want to totally remove any trace of Shorewall from your Netfilter - configuration, use "shorewall clear".
-+ running firewall may be restarted using the "shorewall restart" +command. If you want to totally remove any trace of Shorewall from +your Netfilter configuration, use "shorewall clear". ++ +- --
- The two-interface sample assumes that you want to enable - routing to/from eth1 (the local network) when Shorewall is stopped. - If your local network isn't connected to eth1 or if you wish to - enable access to/from other hosts, change /etc/shorewall/routestopped - accordingly.
+ The two-interface sample assumes that you want to enable + routing to/from eth1 (the local network) when Shorewall is +stopped. If your local network isn't connected to eth1 or if you +wish to enable access to/from other hosts, change /etc/shorewall/routestopped + accordingly. ++ +- -WARNING: If you are connected to your firewall from - the internet, do not issue a "shorewall stop" command unless you -have added an entry for the IP address that you are connected from -to /etc/shorewall/routestopped. - Also, I don't recommend using "shorewall restart"; it is better to create - an alternate configuration - and test it using the /etc/shorewall/routestopped. + Also, I don't recommend using "shorewall restart"; it is better to create + an alternate configuration + and test it using the "shorewall try" command.
-Last updated 1/21/2003 - + +
Last updated 2/13/2003 - Tom Eastep
- +Copyright 2002, 2003 - Thomas M. Eastep
-
-
-
-
-
-
-
-
-
-
-
-
-
+ Thomas M. Eastep
+
diff --git a/Shorewall-docs/upgrade_issues.htm b/Shorewall-docs/upgrade_issues.htm index 88f1cbcd7..ecc24f0cd 100755 --- a/Shorewall-docs/upgrade_issues.htm +++ b/Shorewall-docs/upgrade_issues.htm @@ -1,233 +1,294 @@ - +Upgrade Issues - + + - + - + - +- -
- +- +- + + - - + + + ++ -Upgrade Issues
-For upgrade instructions see the Install/Upgrade page.
- -Version >= 1.3.14
-- Beginning in version 1.3.14, Shorewall treats entries in /etc/shorewall/masq differently. The change -involves entries with an interface name in the SUBNET (second) -column:
+ ++ +
Version >= 1.4.0
+ If you are upgrading from a version < 1.4.0, then:
+ ++
- The noping and forwardping interface options are no +longer supported nor is the FORWARDPING option in shorewall.conf. ICMP +echo-request (ping) packets are treated just like any other connection request +and are subject to rules and policies.
+- Interface names of the form <device>:<integer> in /etc/shorewall/interfaces + now generate a Shorewall error at startup (they always have produced warnings + in iptables).
+- The MERGE_HOSTS variable has been removed from shorewall.conf. Shorewall +1.4 behaves like 1.3 did when MERGE_HOSTS=Yes; that is zone contents are +determined by BOTH the interfaces and hosts files when there are entries +for the zone in both files.
+- The routestopped option in the interfaces and hosts file has + been eliminated; use entries in the routestopped file instead.
+- The Shorewall 1.2 syntax for DNAT and REDIRECT rules is no longer + accepted; you must convert to using the new syntax.
+- The ALLOWRELATED variable in shorewall.conf is no longer + supported. Shorewall 1.4 behavior is the same as 1.3 with ALLOWRELATED=Yes.
+- Late-arriving DNS replies are not dropped by default; there + is no need for your own /etc/shorewall/common file simply to avoid logging + these packets.
+- The 'firewall', 'functions' and 'version' file have been + moved to /usr/share/shorewall.
+- The icmp.def file has been removed. If you include it from +/etc/shorewall/icmpdef, you will need to modify that file.
+- The 'multi' interface option is no longer supported. Shorewall +will generate rules for sending packets back out the same interface that they +arrived on in two cases:
+-
- You will need to make a change to your configuration if:- Prior to 1.3.14, Shorewall would detect the FIRST subnet on the interface -(as shown by "ip addr show interface") and would masquerade traffic -from that subnet. Any other subnets that routed through eth1 needed their -own entry in /etc/shorewall/masq to be masqueraded or to have SNAT applied.
-- Beginning with Shorewall 1.3.14, Shorewall uses the firewall's routing -table to determine ALL subnets routed through the named interface. Traffic -originating in ANY of those subnets is masqueraded or has SNAT applied.
- ++
+- There is an explicit policy for the source zone to or from +the destination zone. An explicit policy names both zones and does not use +the 'all' reserved word.
++
- There are one or more rules for traffic for the source zone to or +from the destination zone including rules that use the 'all' reserved word. +Exception: if the source zone and destination zone are the same then the rule +must be explicit - it must name the zone in both the SOURCE and DESTINATION +columns.
+
- --
- Two examples:- You have one or more entries in /etc/shorewall/masq with an interface -name in the SUBNET (second) column; and
-- That interface connects to more than one subnetwork.
- -
-
- Example 1 -- Suppose that your current config is as follows:
-
- -[root@gateway test]# cat /etc/shorewall/masq- -
#INTERFACE SUBNET ADDRESS
eth0 eth2 206.124.146.176
eth0 192.168.10.0/24 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE
[root@gateway test]# ip route show dev eth2
192.168.1.0/24 scope link
192.168.10.0/24 proto kernel scope link src 192.168.10.254
[root@gateway test]#In this case, the second entry in /etc/shorewall/masq is no longer -required.- Example 2-- What if your current configuration is like this?
-
- -[root@gateway test]# cat /etc/shorewall/masq- -
#INTERFACE SUBNET ADDRESS
eth0 eth2 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE
[root@gateway test]# ip route show dev eth2
192.168.1.0/24 scope link
192.168.10.0/24 proto kernel scope link src 192.168.10.254
[root@gateway test]#In this case, you would want to change the entry in /etc/shorewall/masq -to:- -
-#INTERFACE SUBNET ADDRESS-
eth0 192.168.1.0/24 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE- Version 1.3.14 also introduced simplified ICMP echo-request (ping) handling. -The option OLD_PING_HANDLING=Yes in /etc/shorewall/shorewall.conf is used -to specify that the old (pre-1.3.14) ping handling is to be used (If the -option is not set in your /etc/shorewall/shorewall.conf then OLD_PING_HANDLING=Yes -is assumed). I don't plan on supporting the old handling indefinitely so -I urge current users to migrate to using the new handling as soon as possible. -See the 'Ping' handling documentation for details.
-Version 1.3.10
- If you have installed the 1.3.10 Beta 1 RPM and are now upgrading to version - 1.3.10, you will need to use the '--force' option:
-
+-
--+rpm -Uvh --force shorewall-1.3.10-1.noarch.rpm-Version >= 1.3.9
- The 'functions' file has moved to /usr/lib/shorewall/functions. If you - have an application that uses functions from that file, your application - will need to be changed to reflect this change of location.
+Version >= 1.3.14
++ Beginning in version 1.3.14, Shorewall treats entries in /etc/shorewall/masq differently. The change + involves entries with an interface name in the SUBNET (second) + column:
+ ++
+ You will need to make a change to your configuration if:- Prior to 1.3.14, Shorewall would detect the FIRST subnet on the +interface (as shown by "ip addr show interface") and would masquerade +traffic from that subnet. Any other subnets that routed through eth1 needed +their own entry in /etc/shorewall/masq to be masqueraded or to have SNAT +applied.
+- Beginning with Shorewall 1.3.14, Shorewall uses the firewall's +routing table to determine ALL subnets routed through the named interface. +Traffic originating in ANY of those subnets is masqueraded or has SNAT +applied.
+ +
-Version >= 1.3.8
- -If you have a pair of firewall systems configured for failover - or if you have asymmetric routing, you will need to modify - your firewall setup slightly under Shorewall - versions >= 1.3.8. Beginning with version 1.3.8, - you must set NEWNOTSYN=Yes in your - /etc/shorewall/shorewall.conf file.
- -Version >= 1.3.7
- -Users specifying ALLOWRELATED=No in /etc/shorewall.conf - will need to include the following rules - in their /etc/shorewall/icmpdef file (creating - this file if necessary):
- -run_iptables -A icmpdef -p ICMP --icmp-type echo-reply -j ACCEPT- -
run_iptables -A icmpdef -p ICMP --icmp-type source-quench -j ACCEPT
run_iptables -A icmpdef -p ICMP --icmp-type destination-unreachable -j ACCEPT
run_iptables -A icmpdef -p ICMP --icmp-type time-exceeded -j ACCEPT
run_iptables -A icmpdef -p ICMP --icmp-type parameter-problem -j ACCEPTUsers having an /etc/shorewall/icmpdef file may remove the ". /etc/shorewall/icmp.def" - command from that file since the icmp.def file is now empty.
- -Upgrading Bering to - Shorewall >= 1.3.3
- -To properly upgrade with Shorewall version - 1.3.3 and later:
--
+ Two examples:- Be sure you have a backup -- you - will need to transcribe any Shorewall configuration - changes that you have made to the new - configuration.
-- Replace the shorwall.lrp package - provided on the Bering floppy with the -later one. If you did not obtain the later -version from Jacques's site, see additional -instructions below.
-- Edit the /var/lib/lrpkg/root.exclude.list - file and remove the /var/lib/shorewall - entry if present. Then do not forget to - backup root.lrp !
+- You have one or more entries in /etc/shorewall/masq with an interface + name in the SUBNET (second) column; and
+- That interface connects to more than one subnetwork.
+ +
+
+ Example 1 -- Suppose that your current config is as follows:
+
+ +[root@gateway test]# cat /etc/shorewall/masq+ +
#INTERFACE SUBNET ADDRESS
eth0 eth2 206.124.146.176
eth0 192.168.10.0/24 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE
[root@gateway test]# ip route show dev eth2
192.168.1.0/24 scope link
192.168.10.0/24 proto kernel scope link src 192.168.10.254
[root@gateway test]#In this case, the second entry in /etc/shorewall/masq is no longer + required.+ Example 2-- What if your current configuration is like this?
+
+ +[root@gateway test]# cat /etc/shorewall/masq+ +
#INTERFACE SUBNET ADDRESS
eth0 eth2 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE
[root@gateway test]# ip route show dev eth2
192.168.1.0/24 scope link
192.168.10.0/24 proto kernel scope link src 192.168.10.254
[root@gateway test]#In this case, you would want to change the entry in /etc/shorewall/masq + to:+ +
+#INTERFACE SUBNET ADDRESS+
eth0 192.168.1.0/24 206.124.146.176
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE+ Version 1.3.14 also introduced simplified ICMP echo-request (ping) +handling. The option OLD_PING_HANDLING=Yes in /etc/shorewall/shorewall.conf +is used to specify that the old (pre-1.3.14) ping handling is to be used +(If the option is not set in your /etc/shorewall/shorewall.conf then OLD_PING_HANDLING=Yes + is assumed). I don't plan on supporting the old handling indefinitely so +I urge current users to migrate to using the new handling as soon as possible. + See the 'Ping' handling documentation for details.
+ +Version 1.3.10
+ If you have installed the 1.3.10 Beta 1 RPM and are now upgrading to +version 1.3.10, you will need to use the '--force' option:
+
+ +++ +rpm -Uvh --force shorewall-1.3.10-1.noarch.rpm+Version >= 1.3.9
+ The 'functions' file has moved to /usr/lib/shorewall/functions. If +you have an application that uses functions from that file, your application + will need to be changed to reflect this change of location.
+ +Version >= 1.3.8
+ +If you have a pair of firewall systems configured for failover + or if you have asymmetric routing, you will need to modify + your firewall setup slightly under Shorewall + versions >= 1.3.8. Beginning with version 1.3.8, + you must set NEWNOTSYN=Yes in your + /etc/shorewall/shorewall.conf file.
+ +Version >= 1.3.7
+ +Users specifying ALLOWRELATED=No in /etc/shorewall.conf + will need to include the following rules + in their /etc/shorewall/icmpdef file (creating + this file if necessary):
+ +run_iptables -A icmpdef -p ICMP --icmp-type echo-reply -j ACCEPT+ +
run_iptables -A icmpdef -p ICMP --icmp-type source-quench -j ACCEPT
run_iptables -A icmpdef -p ICMP --icmp-type destination-unreachable -j ACCEPT
run_iptables -A icmpdef -p ICMP --icmp-type time-exceeded -j ACCEPT
run_iptables -A icmpdef -p ICMP --icmp-type parameter-problem -j ACCEPTUsers having an /etc/shorewall/icmpdef file may remove the ". /etc/shorewall/icmp.def" + command from that file since the icmp.def file is now empty.
+ +Upgrading Bering to + Shorewall >= 1.3.3
+ +To properly upgrade with Shorewall version + 1.3.3 and later:
+ ++
+ +- Be sure you have a backup -- + you will need to transcribe any Shorewall + configuration changes that you have made + to the new configuration.
+- Replace the shorwall.lrp package + provided on the Bering floppy with the + later one. If you did not obtain the +later version from Jacques's site, see +additional instructions below.
+- Edit the /var/lib/lrpkg/root.exclude.list + file and remove the /var/lib/shorewall + entry if present. Then do not forget to + backup root.lrp !
+ +The .lrp that I release isn't set up for a two-interface firewall like + Jacques's. You need to follow the instructions + for setting up a two-interface firewall plus you also need to add + the following two Bering-specific rules to /etc/shorewall/rules:
+ +++ +# Bering specific rules:+
# allow loc to fw udp/53 for dnscache to work
# allow loc to fw tcp/80 for weblet to work
#
ACCEPT loc fw udp 53
ACCEPT loc fw tcp 80Version 1.3.6 and 1.3.7
+ +If you have a pair of firewall systems configured for + failover or if you have asymmetric routing, you will need to modify + your firewall setup slightly under Shorewall versions 1.3.6 + and 1.3.7
+ ++
- -- + +
+Create the file /etc/shorewall/newnotsyn and in it add + the following rule
+
+
+ run_iptables -A newnotsyn -j RETURN + # So that the connection tracking table can be rebuilt
+ # from non-SYN packets + after takeover.
+- + +
Create /etc/shorewall/common (if you don't already + have that file) and include the following:
+
+
+ run_iptables -A common -p tcp --tcp-flags + ACK,FIN,RST ACK -j ACCEPT #Accept Acks to rebuild connection
+ + #tracking table.
+ . /etc/shorewall/common.defThe .lrp that I release isn't set up for a two-interface firewall like - Jacques's. You need to follow the instructions - for setting up a two-interface firewall plus you also need to add - the following two Bering-specific rules to /etc/shorewall/rules:
- --- -# Bering specific rules:-
# allow loc to fw udp/53 for dnscache to work
# allow loc to fw tcp/80 for weblet to work
#
ACCEPT loc fw udp 53
ACCEPT loc fw tcp 80Version 1.3.6 and 1.3.7
- -If you have a pair of firewall systems configured for - failover or if you have asymmetric routing, you will need to modify - your firewall setup slightly under Shorewall versions 1.3.6 -and 1.3.7
- --
- +- - -
-Create the file /etc/shorewall/newnotsyn and in it add - the following rule
-
-
- run_iptables -A newnotsyn -j RETURN -# So that the connection tracking table can be rebuilt
- # from non-SYN packets - after takeover.
-- -
- -Create /etc/shorewall/common (if you don't already - have that file) and include the following:
-
-
- run_iptables -A common -p tcp --tcp-flags - ACK,FIN,RST ACK -j ACCEPT #Accept Acks to rebuild connection
- - #tracking table.
- . /etc/shorewall/common.defVersions >= 1.3.5
- -Some forms of pre-1.3.0 rules file syntax are no - longer supported.
- + +Some forms of pre-1.3.0 rules file syntax are no + longer supported.
+Example 1:
- -+ ++- +ACCEPT net loc:192.168.1.12:22 tcp 11111 - all-Must be replaced with:
- -+ ++- -DNAT net loc:192.168.1.12:22 tcp 11111-++ +- -Example 2:
-++ +- -ACCEPT loc fw::3128 tcp 80 - all-++ +- -Must be replaced with:
-++ +- +REDIRECT loc 3128 tcp 80-Version >= 1.3.2
- -The functions and versions files together with the - 'firewall' symbolic link have moved from /etc/shorewall to /var/lib/shorewall. - If you have applications that access these files, those applications - should be modified accordingly.
- -Last updated 1/25/2003 - - Tom Eastep
- -Copyright - © 2001, 2002, 2003 Thomas M. Eastep.
+ +
-The functions and versions files together with the + 'firewall' symbolic link have moved from /etc/shorewall to /var/lib/shorewall. + If you have applications that access these files, those applications + should be modified accordingly.
+ +Last updated 2/14/2003 - + Tom Eastep
+ +Copyright + © 2001, 2002, 2003 Thomas M. Eastep.
+
+
+
+
diff --git a/Shorewall-docs/whitelisting_under_shorewall.htm b/Shorewall-docs/whitelisting_under_shorewall.htm index c0a706c56..47518f19d 100644 --- a/Shorewall-docs/whitelisting_under_shorewall.htm +++ b/Shorewall-docs/whitelisting_under_shorewall.htm @@ -1,281 +1,326 @@ + - - - - - -Whitelisting under Shorewall + + + + + + + + +Whitelisting under Shorewall - - - --
+ + +- + + +- -Whitelisting under Shorewall
-+ +
-+ + ++ +Whitelisting under Shorewall
+For a brief time, the 1.2 version of Shorewall supported an -/etc/shorewall/whitelist file. This file was intended to contain a list of IP -addresses of hosts whose POLICY to all zones was ACCEPT. The whitelist file was -implemented as a stop-gap measure until the facilities necessary for -implementing white lists using zones was in place. As of Version 1.3 RC1, those -facilities were available.
-White lists are most often used to give special privileges to a -set of hosts within an organization. Let us suppose that we have the -following environment:
+ +For a brief time, the 1.2 version of Shorewall supported an + /etc/shorewall/whitelist file. This file was intended to contain a list of +IP addresses of hosts whose POLICY to all zones was ACCEPT. The whitelist +file was implemented as a stop-gap measure until the facilities necessary +for implementing white lists using zones was in place. As of Version 1.3 +RC1, those facilities were available.
+ +White lists are most often used to give special privileges +to a set of hosts within an organization. Let us suppose that we have the + following environment:
+-
+- A firewall with three interfaces -- one to the internet, one - to a local network and one to a DMZ.
-- The local network uses SNAT to the internet and is comprised - of the class B network 10.10.0.0/16 (Note: While this example uses an RFC 1918 - local network, the technique described here in no way depends on that or on - SNAT. It may be used with Proxy ARP, Subnet Routing, Static NAT, etc.).
-- The network operations staff have workstations with IP - addresses in the class C network 10.10.10.0/24
-- We want the network operations staff to have full access to - all other hosts.
-- We want the network operations staff to bypass the transparent - HTTP proxy running on our firewall.
+- A firewall with three interfaces -- one to the internet, one to +a local network and one to a DMZ.
+- The local network uses SNAT to the internet and is comprised of +the class B network 10.10.0.0/16 (Note: While this example uses an RFC 1918 + local network, the technique described here in no way depends on that or +on SNAT. It may be used with Proxy ARP, Subnet Routing, Static NAT, etc.).
+- The network operations staff have workstations with IP addresses +in the class C network 10.10.10.0/24
+- We want the network operations staff to have full access to all +other hosts.
+- We want the network operations staff to bypass the transparent + HTTP proxy running on our firewall.
+The basic approach will be that we will place the operations -staff's class C in its own zone called ops. Here are the appropriate -configuration files:
+ staff's class C in its own zone called ops. Here are the appropriate + configuration files: +Zone File
-+ +--
-- - +- ZONE -- DISPLAY -- COMMENTS -- -net -Net -Internet -- -ops -Operations -Operations Staff's Class C -- -loc -Local -Local Class B -- - -dmz -DMZ -Demilitarized zone -The ops zone has been added to the standard 3-zone zones file -- since -ops is a sub-zone of loc, we list it BEFORE loc.
+ZONE +DISPLAY +COMMENTS + ++ +net +Net +Internet ++ +ops +Operations +Operations Staff's Class C ++ +loc +Local +Local Class B ++ + + +dmz +DMZ +Demilitarized zone +The ops zone has been added to the standard 3-zone zones file -- +since ops is a sub-zone of loc, we list it BEFORE loc.
+Interfaces File
-+ ++ +--
-- +- ZONE -- INTERFACE -- BROADCAST -- OPTIONS -- -net -eth0 -<whatever> -<options> -- -dmz -eth1 -<whatever> -routestopped -- - -- -eth2 -10.10.255.255 -- Because eth2 interfaces to two zones (ops and loc), we -don't specify a zone for it here.
+ZONE +INTERFACE +BROADCAST +OPTIONS + ++ +net +eth0 +<whatever> +<options> ++ +dmz +eth1 +<whatever> ++
++ + + + + +- +eth2 +10.10.255.255 ++ Because eth2 interfaces to two zones (ops and loc), +we don't specify a zone for it here.
+Hosts File
-+ +++ ++-
-- +- ZONE -- HOST(S) -- OPTIONS -- -ops -eth2:10.10.10.0/24 - - - -routestopped - -- - -loc -eth2:0.0.0.0/0 -- ZONE +HOST(S) +OPTIONS + ++ +ops +eth2:10.10.10.0/24 ++
++ + + + + +loc +eth2:0.0.0.0/0 ++ Here we define the ops and loc zones. When Shorewall is -stopped, only the hosts in the ops zone will be allowed to access the -firewall and the DMZ. I use 0.0.0.0/0 to define the loc zone rather than -10.10.0.0/16 so that the limited broadcast address (255.255.255.255) falls into -that zone. If I used 10.10.0.0/16 then I would have to have a separate entry for -that special address.
+stopped, only the hosts in the ops zone will be allowed to access the + firewall and the DMZ. I use 0.0.0.0/0 to define the loc zone rather +than 10.10.0.0/16 so that the limited broadcast address (255.255.255.255) +falls into that zone. If I used 10.10.0.0/16 then I would have to have a +separate entry for that special address. +Policy File
----
-- -SOURCE -DEST -- POLICY -- LOG LEVEL -LIMIT:BURST -- -ops -all -ACCEPT - - -- - - - - -all -ops -CONTINUE - - -- - - - - -loc -net -ACCEPT - - - -- - - - - - -net -all -DROP -info -- - - + +all -all -REJECT -info -- + -Two entries for ops have been added to the standard 3-zone policy file. -WARNING: You must be running Shorewall 1.3.1 or later -for the above to work properly.
++ +
+ + ++ +SOURCE +DEST +POLICY +LOG LEVEL +LIMIT:BURST ++ +ops +all +ACCEPT + ++ + + + +all +ops +CONTINUE + ++ + + + +loc +net +ACCEPT ++ + + + +net +all +DROP +info ++ + + + + +all +all +REJECT +info ++ Two entries for ops have been added to the standard 3-zone policy +file.
+Rules File
+ ++ ++ ++ +
++ +ACTION +SOURCE +DEST +PROTO +DEST +
+ PORT(S)SOURCE +
+ PORT(S)ORIGINAL +
+ DEST+ +REDIRECT +loc!ops +3128 +tcp +http ++ + + + + + + +... ++ + + + + + This is the rule that transparently redirects web traffic to the transparent + proxy running on the firewall. The SOURCE column explicitly excludes the +ops zone from the rule.
+Routestopped File
+--
+ + + +- - -ACTION -SOURCE -DEST -- PROTO -DEST -
- PORT(S)SOURCE -
- PORT(S)ORIGINAL - -
- DEST- -REDIRECT -loc!ops -3128 -tcp -http -- - - + +... -- - - - - - + +INTERFACE +
+HOST(S) ++ +eth1 +
++
++ - -eth2 +
+10.10.10.0/24 +
This is the rule that transparently redirects web traffic to the transparent -proxy running on the firewall. The SOURCE column explicitly excludes the ops -zone from the rule.
- -- Updated 5/31/2002 - Tom -Eastep -
+ + +Updated 2/18/2003 - Tom Eastep +
- -Copyright - © 2002 Thomas M. Eastep.
+ +Copyright + © 2002, 2003Thomas M. Eastep.
- - - - \ No newline at end of file +
+
+ +