shorewall_code/Shorewall/Documenation

2561 lines
87 KiB
Plaintext
Raw Normal View History

################################################################################
This documentation provides a quick reference to the configuration
files.
Please refer to http://www.shorewall.net/Documentation_Index.html for
the complete Shorewall documentation.
Copyright © 2006 Thomas M. Eastep
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.2 or
any later version published by the Free Software Foundation; with no
Invariant Sections, with no Front-Cover, and with no Back-Cover Texts.
################################################################################
/etc/shorewall/accounting
Accounting rules exist simply to count packets and bytes in categories
that you define in this file. You may display these rules and their
packet and byte counters using the "shorewall show accounting" command.
Please see http://shorewall.net/Accounting.html for examples and
additional information about how to use this file.
Columns are:
ACTION - What to do when a match is found.
COUNT - Simply count the match and continue
with the next rule
DONE - Count the match and don't attempt
to match any other accounting rules
in the chain specified in the CHAIN
column.
<chain>[:COUNT]
- Where <chain> is the name of
a chain. Shorewall will create
the chain automatically if it
doesn't already exist. Causes
a jump to that chain. If :COUNT
is including, a counting rule
matching this record will be
added to <chain>
CHAIN - The name of a chain. If specified as "-" the
'accounting' chain is assumed. This is the chain
where the accounting rule is added. The chain will
be created if it doesn't already exist.
SOURCE - Packet Source
The name of an interface, an address (host or net) or
an interface name followed by ":"
and a host or net address.
DESTINATION - Packet Destination
Format the same as the SOURCE column.
PROTOCOL A protocol name (from /etc/protocols), a protocol
number, "ipp2p", "ipp2p:udp" or "ipp2p:all"
DEST PORT(S) Destination Port number. If the PROTOCOL is "ipp2p"
then this column must contain an ipp2p option
("iptables -m ipp2p --help") without the leading
"--". If no option is given in this column, "ipp2p"
is assumed.
Service name from /etc/services or port number. May
only be specified if the protocol is TCP or UDP (6
or 17).
You may place a comma-separated list of port numbers in
this column if your kernel and iptables include
multiport match support.
SOURCE PORT(S) Source Port number
Service name from /etc/services or port number. May
only be specified if the protocol is TCP or UDP (6
or 17).
You may place a comma-separated list of port numbers in
this column if your kernel and iptables include
multiport match support.
USER/GROUP This column may only be non-empty if the CHAIN is
OUTPUT.
The column may contain:
[!][<user name or number>][:<group name or number>][+<program name>]
When this column is non-empty, the rule applies only
if the program generating the output is running under
the effective <user> and/or <group> specified (or is
NOT running under that id if "!" is given).
Examples:
joe #program must be run by joe
:kids #program must be run by a member of
#the 'kids' group
!:kids #program must not be run by a member
#of the 'kids' group
+upnpd #program named upnpd (This feature was
#removed from Netfilter in kernel
#version 2.6.14).
In all of the above columns except ACTION and CHAIN, the values "-",
"any" and "all" may be used as wildcards. Omitted trailing columns are
also treated as wildcards.
Please see http://shorewall.net/Accounting.html for examples and
additional information about how to use this file.
################################################################################
/etc/shorewall/blacklist
This file contains a list of IP addresses, MAC addresses and/or
subnetworks.
Columns are:
ADDRESS/SUBNET - Host address, subnetwork, MAC address, IP address
range (if your kernel and iptables contain iprange
match support) or ipset name prefaced by "+" (if
your kernel supports ipset match).
MAC addresses must be prefixed with "~" and use "-"
as a separator.
Example: ~00-A0-C9-15-39-78
A dash ("-") in this column means that any source
address will match. This is useful if you want to
blacklist a particular application.
PROTOCOL - Optional. If specified, must be a protocol number
or a protocol name from /etc/protocols.
PORTS - Optional. May only be specified if the protocol
is TCP (6) or UDP (17). A comma-separated list
of destination port numbers or service names from
/etc/services.
When a packet arrives on an interface that has the 'blacklist' option
specified in /etc/shorewall/interfaces, its source IP address is
checked against this file and disposed of according to the
BLACKLIST_DISPOSITION and BLACKLIST_LOGLEVEL variables in
/etc/shorewall/shorewall.conf
If PROTOCOL or PROTOCOL and PORTS are supplied, only packets matching
the protocol (and one of the ports if PORTS supplied) are blocked.
Example:
To block DNS queries from address 192.0.2.126:
ADDRESS/SUBNET PROTOCOL PORT
192.0.2.126 udp 53
Example:
To block DNS queries from addresses in the ipset 'dnsblack':
ADDRESS/SUBNET PROTOCOL PORT
+dnsblack udp 53
Please see http://shorewall.net/blacklisting_support.htm for additional
information.
################################################################################
/etc/shorewall/ecn
Use this file to list the destinations for which you want to
disable ECN.
This feature requires kernel 2.4.20 or later. If you run 2.4.20,
you also need the patch found at http://www.shorewall.net/ecn/patch.
That patch is included in kernels 2.4.21 and later.
INTERFACE - Interface through which host(s) communicate with
the firewall
HOST(S) - (Optional) Comma-separated list of IP/subnet
If left empty or supplied as "-",
0.0.0.0/0 is assumed. If your kernel and iptables
include iprange match support then IP address ranges
are also permitted.
For additional information, see http://shorewall.net/Documentation.htm#ECN
################################################################################
/etc/shorewall/hosts
THE ONLY TIME YOU NEED THIS FILE IS WHERE YOU HAVE MORE THAN
ONE ZONE CONNECTED THROUGH A SINGLE INTERFACE.
IF YOU DON'T HAVE THAT SITUATION THEN DON'T TOUCH THIS FILE.
------------------------------------------------------------------------------
IF YOU HAVE AN ENTRY FOR A ZONE AND INTERFACE IN
/etc/shorewall/interfaces THEN DO NOT ADD ANY ENTRIES FOR THAT
ZONE AND INTERFACE IN THIS FILE.
------------------------------------------------------------------------------
This file is used to define zones in terms of subnets and/or
individual IP addresses. Most simple setups don't need to
(should not) place anything in this file.
The order of entries in this file is not significant in
determining zone composition. Rather, the order that the zones
are defined in /etc/shorewall/zones determines the order in
which the records in this file are interpreted.
ZONE - The name of a zone defined in /etc/shorewall/zones. You may
not list the firewall zone in this column.
HOST(S) - The name of an interface defined in the
/etc/shorewall/interfaces file followed by a colon (":") and
a comma-separated list whose elements are either:
a) The IP address of a host
b) A subnetwork in the form
<subnet-address>/<mask width>
c) An IP address range of the form <low address>-<high
address>. Your kernel and iptables must have iprange
match support.
d) A physical port name; only allowed when the
interface names a bridge created by the
brctl addbr command. This port must not
be defined in /etc/shorewall/interfaces and may
optionally followed by a colon (":") and a
host or network IP or a range.
See http://www.shorewall.net/bridge.html
for details. Specifying a physical port
name requires that you have BRIDGING=Yes in
/etc/shorewall/shorewall.conf.
e) The name of an ipset (preceded by "+").
Examples:
eth1:192.168.1.3
eth2:192.168.2.0/24
eth3:192.168.2.0/24,192.168.3.1
br0:eth4
br0:eth0:192.168.1.16/28
eth4:192.168.1.44-192.168.1.49
eth2:+Admin
OPTIONS - A comma-separated list of options. Currently-defined
options are:
maclist - Connection requests from these hosts
are compared against the contents of
/etc/shorewall/maclist. If this option
is specified, the interface must be
an ethernet NIC and must be up before
Shorewall is started.
routeback - Shorewall should set up the
infrastructure to pass packets
from this/these address(es) back
to themselves. This is necessary if
hosts in this group use the services
of a transparent proxy that is
a member of the group or if DNAT is used
to send requests originating from this
group to a server in the group.
norfc1918 - This option only makes sense for ports
on a bridge.
The port should not accept
any packets whose source is in one
of the ranges reserved by RFC 1918
(i.e., private or "non-routable"
addresses. If packet mangling or
connection-tracking match is enabled in
your kernel, packets whose destination
addresses are reserved by RFC 1918 are
also rejected.
blacklist - This option only makes sense for ports
on a bridge.
Check packets arriving on this port
against the /etc/shorewall/blacklist
file.
tcpflags - Packets arriving from these hosts are
checked for certain illegal combinations
of TCP flags. Packets found to have
such a combination of flags are handled
according to the setting of
TCP_FLAGS_DISPOSITION after having been
logged according to the setting of
TCP_FLAGS_LOG_LEVEL.
nosmurfs - This option only makes sense for ports
on a bridge.
Filter packets for smurfs
(packets with a broadcast
address as the source).
Smurfs will be optionally logged based
on the setting of SMURF_LOG_LEVEL in
shorewall.conf. After logging, the
packets are dropped.
ipsec - The zone is accessed via a
kernel 2.6 ipsec SA. Note that if the
zone named in the ZONE column is
specified as an IPSEC zone in the
/etc/shorewall/zones file then you
do NOT need to specify the 'ipsec'
option here.
For additional information, see http://shorewall.net/Documentation.htm#Hosts
################################################################################
/etc/shorewall/interfaces
You must add an entry in this file for each network interface on your
firewall system.
Columns are:
ZONE Zone for this interface. Must match the name of a
zone defined in /etc/shorewall/zones. You may not
list the firewall zone in this column.
If the interface serves multiple zones that will be
defined in the /etc/shorewall/hosts file, you should
place "-" in this column.
If there are multiple interfaces to the same zone,
you must list them in separate entries:
Example:
loc eth1 -
loc eth2 -
INTERFACE Name of interface. Each interface may be listed only
once in this file. You may NOT specify the name of
an alias (e.g., eth0:0) here; see
http://www.shorewall.net/FAQ.htm#faq18
You may specify wildcards here. For example, if you
want to make an entry that applies to all PPP
interfaces, use 'ppp+'.
There is no need to define the loopback interface (lo)
in this file.
BROADCAST The broadcast address for the subnetwork to which the
interface belongs. For P-T-P interfaces, this
column is left blank.If the interface has multiple
addresses on multiple subnets then list the broadcast
addresses as a comma-separated list.
If you use the special value "detect", Shorewall
will detect the broadcast address(es) for you. If you
select this option, the interface must be up before
the firewall is started.
If you don't want to give a value for this column but
you want to enter a value in the OPTIONS column, enter
"-" in this column.
OPTIONS A comma-separated list of options including the
following:
dhcp - Specify this option when any of
the following are true:
1. the interface gets its IP address
via DHCP
2. the interface is used by
a DHCP server running on the firewall
3. you have a static IP but are on a LAN
segment with lots of Laptop DHCP
clients.
4. the interface is a bridge with
a DHCP server on one port and DHCP
clients on another port.
norfc1918 - This interface should not receive
any packets whose source is in one
of the ranges reserved by RFC 1918
(i.e., private or "non-routable"
addresses). If packet mangling or
connection-tracking match is enabled in
your kernel, packets whose destination
addresses are reserved by RFC 1918 are
also rejected.
routefilter - turn on kernel route filtering for this
interface (anti-spoofing measure). This
option can also be enabled globally in
the /etc/shorewall/shorewall.conf file.
logmartians - turn on kernel martian logging (logging
of packets with impossible source
addresses. It is suggested that if you
set routefilter on an interface that
you also set logmartians. This option
may also be enabled globally in the
/etc/shorewall/shorewall.conf file.
blacklist - Check packets arriving on this interface
against the /etc/shorewall/blacklist
file.
maclist - Connection requests from this interface
are compared against the contents of
/etc/shorewall/maclist. If this option
is specified, the interface must be
an ethernet NIC and must be up before
Shorewall is started.
tcpflags - Packets arriving on this interface are
checked for certain illegal combinations
of TCP flags. Packets found to have
such a combination of flags are handled
according to the setting of
TCP_FLAGS_DISPOSITION after having been
logged according to the setting of
TCP_FLAGS_LOG_LEVEL.
proxyarp -
Sets
/proc/sys/net/ipv4/conf/<interface>/proxy_arp.
Do NOT use this option if you are
employing Proxy ARP through entries in
/etc/shorewall/proxyarp. This option is
intended soley for use with Proxy ARP
sub-networking as described at:
http://www.tldp.org/HOWTO/mini/Proxy-ARP-Subnet
routeback - If specified, indicates that Shorewall
should include rules that allow
filtering traffic arriving on this
interface back out that same interface.
arp_filter - If specified, this interface will only
respond to ARP who-has requests for IP
addresses configured on the interface.
If not specified, the interface can
respond to ARP who-has requests for
IP addresses on any of the firewall's
interface. The interface must be up
when Shorewall is started.
arp_ignore[=<number>]
- If specified, this interface will
respond to arp requests based on the
value of <number>.
1 - reply only if the target IP address
is local address configured on the
incoming interface
2 - reply only if the target IP address
is local address configured on the
incoming interface and both with the
sender's IP address are part from same
subnet on this interface
3 - do not reply for local addresses
configured with scope host, only
resolutions for global and link
addresses are replied
4-7 - reserved
8 - do not reply for all local
addresses
If no <number> is given then the value
1 is assumed
WARNING -- DO NOT SPECIFY arp_ignore
FOR ANY INTERFACE INVOLVED IN PROXY ARP.
nosmurfs - Filter packets for smurfs
(packets with a broadcast
address as the source).
Smurfs will be optionally logged based
on the setting of SMURF_LOG_LEVEL in
shorewall.conf. After logging, the
packets are dropped.
detectnets - Automatically taylors the zone named
in the ZONE column to include only those
hosts routed through the interface.
sourceroute - If this option is not specified for an
interface, then source-routed packets
will not be accepted from that
interface (sets /proc/sys/net/ipv4/
conf/<interface>/
accept_source_route to 1).
Only set this option if you know what
you are you doing. This might represent
a security risk and is not usually
needed.
upnp - Incoming requests from this interface
may be remapped via UPNP (upnpd).
WARNING: DO NOT SET THE detectnets OPTION ON YOUR
INTERNET INTERFACE.
The order in which you list the options is not
significant but the list should have no embedded white
space.
Example 1: Suppose you have eth0 connected to a DSL modem and
eth1 connected to your local network and that your
local subnet is 192.168.1.0/24. The interface gets
it's IP address via DHCP from subnet
206.191.149.192/27. You have a DMZ with subnet
192.168.2.0/24 using eth2.
Your entries for this setup would look like:
net eth0 206.191.149.223 dhcp
local eth1 192.168.1.255
dmz eth2 192.168.2.255
Example 2: The same configuration without specifying broadcast
addresses is:
net eth0 detect dhcp
loc eth1 detect
dmz eth2 detect
Example 3: You have a simple dial-in system with no ethernet
connections.
net ppp0 -
For additional information, see
http://shorewall.net/Documentation.htm#Interfaces
################################################################################
/etc/shorewall/maclist
This file is used to define the MAC addresses and optionally their
associated IP addresses to be allowed to use the specified interface.
The feature is enabled by using the maclist option in the interfaces
or hosts configuration file.
Columns are:
DISPOSITION ACCEPT or DROP (if MACLIST_TABLE=filter, then REJECT
is also allowed)
INTERFACE Network interface to a host. If the interface
names a bridge, it may be optionally followed by
a colon (":") and a physical port name (e.g.,
br0:eth4).
MAC MAC address of the host -- you do not need to use
the Shorewall format for MAC addresses here. If IP
ADDRESSES is supplied then MAC can be supplied as
a dash ("-")
IP ADDRESSES Optional -- if specified, both the MAC and IP address
must match. This column can contain a comma-separated
list of host and/or subnet addresses. If your kernel
and iptables have iprange match support then IP
address ranges are also allowed.
For additional information, see http://shorewall.net/MAC_Validation.html
################################################################################
/etc/shorewall/masq
Use this file to define dynamic NAT (Masquerading) and to define
Source NAT (SNAT).
WARNING: The entries in this file are order-sensitive. The first
entry that matches a particular connection will be the one that
is used.
WARNING: If you have more than one ISP, adding entries to this
file will *not* force connections to go out through a particular
ISP. You must use PREROUTING entries in /etc/shorewall/tcrules
to do that.
Columns are:
INTERFACE -- Outgoing interface. This is usually your internet
interface. If ADD_SNAT_ALIASES=Yes in
/etc/shorewall/shorewall.conf, you may add ":" and
a digit to indicate that you want the alias added with
that name (e.g., eth0:0). This will allow the alias to
be displayed with ifconfig. THAT IS THE ONLY USE FOR
THE ALIAS NAME AND IT MAY NOT APPEAR IN ANY OTHER
PLACE IN YOUR SHOREWALL CONFIGURATION.
This may be qualified by adding the character
":" followed by a destination host or subnet.
If you wish to inhibit the action of ADD_SNAT_ALIASES
for this entry then include the ":" but omit the digit:
eth0:
eth2::192.0.2.32/27
Normally Masq/SNAT rules are evaluated after those for
one-to-one NAT (/etc/shorewall/nat file). If you want
the rule to be applied before one-to-one NAT rules,
prefix the interface name with "+":
+eth0
+eth0:192.0.2.32/27
+eth0:2
This feature should only be required if you need to
insert rules in this file that preempt entries in
/etc/shorewall/nat.
If you place COMMENT in this column, then the rest of the
line will be attached as a comment to the Netfilter rule(s)
generated by the following entry. The comment will appear
delimited by "/* ... */" in the output of "shorewall show
nat"
SOURCE (formerly called SUBNET)
Set of hosts that you wish to masquerade. You can specify this
as an address (net or host) or as an interface. If you give
the name of an interface, the interface must be up before you
start the firewall (Shorewall will use your main routing table
to determine the appropriate addresses to masquerade).
In order to exclude a addrress of the specified SOURCE, you
may append "!" and a comma-separated list of IP addresses
(host or net) that you wish to exclude.
Example: eth1!192.168.1.4,192.168.32.0/27
In that example traffic from eth1 would be masqueraded unless
it came from 192.168.1.4 or 196.168.32.0/27
ADDRESS -- (Optional). If you specify an address here, SNAT will be
used and this will be the source address. If
ADD_SNAT_ALIASES is set to Yes or yes in
/etc/shorewall/shorewall.conf then Shorewall
will automatically add this address to the
INTERFACE named in the first column.
You may also specify a range of up to 256
IP addresses if you want the SNAT address to
be assigned from that range in a round-robin
range by connection. The range is specified by
<first ip in range>-<last ip in range>.
Example: 206.124.146.177-206.124.146.180
You may also use the special value "detect"
which causes Shorewall to determine the
IP addresses configured on the interface named
in the INTERFACES column and substitute them
in this column.
Finally, you may also specify a comma-separated
list of ranges and/or addresses in this column.
This column may not contain DNS Names.
Normally, Netfilter will attempt to retain
the source port number. You may cause
netfilter to remap the source port by following
an address or range (if any) by ":" and
a port range with the format <low port>-
<high port>. If this is done, you must
specify "tcp" or "udp" in the PROTO column.
Examples:
192.0.2.4:5000-6000
:4000-5000
You can invoke the SAME target using the
following in this column:
SAME:[nodst:]<address-range>[,<address-range>...]
The <address-ranges> may be single addresses
or "detect" as described above.
SAME works like SNAT with the exception that
the same local IP address is assigned to each
connection from a local address to a given
remote address.
If the 'nodst:' option is included, then the
same source address is used for a given
internal system regardless of which remote
system is involved.
If you want to leave this column empty
but you need to specify the next column then
place a hyphen ("-") here.
PROTO -- (Optional) If you wish to restrict this entry to a
particular protocol then enter the protocol
name (from /etc/protocols) or number here.
PORT(S) -- (Optional) If the PROTO column specifies TCP (protocol 6)
or UDP (protocol 17) then you may list one
or more port numbers (or names from
/etc/services) separated by commas or you
may list a single port range
(<low port>:<high port>).
Where a comma-separated list is given, your
kernel and iptables must have multiport match
support and a maximum of 15 ports may be
listed.
IPSEC -- (Optional) If you specify a value other than "-" in this
column, you must be running kernel 2.6 and
your kernel and iptables must include policy
match support.
Comma-separated list of options from the
following. Only packets that will be encrypted
via an SA that matches these options will have
their source address changed.
Yes or yes -- must be the only option
listed and matches all outbound
traffic that will be encrypted.
reqid=<number> where <number> is
specified using setkey(8) using the
'unique:<number> option for the SPD
level.
spi=<number> where <number> is the
SPI of the SA.
proto=ah|esp|ipcomp
mode=transport|tunnel
tunnel-src=<address>[/<mask>] (only
available with mode=tunnel)
tunnel-dst=<address>[/<mask>] (only
available with mode=tunnel)
strict Means that packets must match
all rules.
next Separates rules; can only be
used with strict..
Example 1:
You have a simple masquerading setup where eth0 connects to
a DSL or cable modem and eth1 connects to your local network
with subnet 192.168.0.0/24.
Your entry in the file can be either:
eth0 eth1
or
eth0 192.168.0.0/24
Example 2:
You add a router to your local network to connect subnet
192.168.1.0/24 which you also want to masquerade. You then
add a second entry for eth0 to this file:
eth0 192.168.1.0/24
Example 3:
You have an IPSEC tunnel through ipsec0 and you want to
masquerade packets coming from 192.168.1.0/24 but only if
these packets are destined for hosts in 10.1.1.0/24:
ipsec0:10.1.1.0/24 196.168.1.0/24
Example 4:
You want all outgoing traffic from 192.168.1.0/24 through
eth0 to use source address 206.124.146.176 which is NOT the
primary address of eth0. You want 206.124.146.176 added to
be added to eth0 with name eth0:0.
eth0:0 192.168.1.0/24 206.124.146.176
Example 5:
You want all outgoing SMTP traffic entering the firewall
on eth1 to be sent from eth0 with source IP address
206.124.146.177. You want all other outgoing traffic
from eth1 to be sent from eth0 with source IP address
206.124.146.176.
eth0 eth1 206.124.146.177 tcp smtp
eth0 eth1 206.124.146.176
THE ORDER OF THE ABOVE TWO RULES IS SIGNIFICANT!!!!!
For additional information, see http://shorewall.net/Documentation.htm#Masq
################################################################################
/etc/shorewall/nat
This file is used to define one-to-one Network Address Translation
(NAT).
WARNING: If all you want to do is simple port forwarding, do NOT use this
file. See http://www.shorewall.net/FAQ.htm#faq1. Also, in most
cases, Proxy ARP is a better solution that one-to-one NAT.
Columns are:
EXTERNAL External IP Address - this should NOT be the primary
IP address of the interface named in the next
column and must not be a DNS Name.
If you put COMMENT in this column, the rest of the
line will be attached as a comment to the Netfilter
rule(s) generated by the following entries in the
file. The comment will appear delimited by "/* ... */"
in the output of "shorewall show nat"
To stop the comment from being attached to further
rules, simply include COMMENT on a line by itself.
INTERFACE Interface that has the EXTERNAL address.
If ADD_IP_ALIASES=Yes in shorewall.conf, Shorewall
will automatically add the EXTERNAL address to this
interface. Also if ADD_IP_ALIASES=Yes, you may
follow the interface name with ":" and a digit to
indicate that you want Shorewall to add the alias
with this name (e.g., "eth0:0"). That allows you to
see the alias with ifconfig. THAT IS THE ONLY THING
THAT THIS NAME IS GOOD FOR -- YOU CANNOT USE IT
ANYWHERE ELSE IN YOUR SHORWALL CONFIGURATION.
If you want to override ADD_IP_ALIASES=Yes for a
particular entry, follow the interface name with
":" and no digit (e.g., "eth0:").
INTERNAL Internal Address (must not be a DNS Name).
ALL INTERFACES If Yes or yes, NAT will be effective from all hosts.
If No or no (or left empty) then NAT will be effective
only through the interface named in the INTERFACE
column
LOCAL If Yes or yes, NAT will be effective from the firewall
system
For additional information, see http://shorewall.net/NAT.htm
################################################################################
/etc/shorewall/netmap
This file is used to map addresses in one network to corresponding
addresses in a second network.
WARNING: To use this file, your kernel and iptables must have
NETMAP support included.
Columns are:
TYPE Must be DNAT or SNAT.
If DNAT, traffic entering INTERFACE and addressed to
NET1 has it's destination address rewritten to the
corresponding address in NET2.
If SNAT, traffic leaving INTERFACE with a source
address in NET1 has it's source address rewritten to
the corresponding address in NET2.
NET1 Network in CIDR format (e.g., 192.168.1.0/24)
INTERFACE The name of a network interface. The interface must
be defined in /etc/shorewall/interfaces.
NET2 Network in CIDR format
See http://shorewall.net/netmap.html for an example and usage
information.
################################################################################
/etc/shorewall/policy
THE ORDER OF ENTRIES IN THIS FILE IS IMPORTANT
This file determines what to do with a new connection request if we
don't get a match from the /etc/shorewall/rules file . For each
source/destination pair, the file is processed in order until a
match is found ("all" will match any client or server).
INTRA-ZONE POLICIES ARE PRE-DEFINED
For $FW and for all of the zoned defined in /etc/shorewall/zones,
the POLICY for connections from the zone to itself is ACCEPT (with no
logging or TCP connection rate limiting but may be overridden by an
entry in this file. The overriding entry must be explicit (cannot use
"all" in the SOURCE or DEST).
Similarly, if you have IMPLICIT_CONTINUE=Yes in shorewall.conf, then
the implicit policy to/from any sub-zone is CONTINUE. These implicit
CONTINUE policies may also be overridden by an explicit entry in this
file.
Columns are:
SOURCE Source zone. Must be the name of a zone defined
in /etc/shorewall/zones, $FW or "all".
DEST Destination zone. Must be the name of a zone defined
in /etc/shorewall/zones, $FW or "all"
POLICY Policy if no match from the rules file is found. Must
be "ACCEPT", "DROP", "REJECT", "CONTINUE" or "NONE".
ACCEPT - Accept the connection
DROP - Ignore the connection request
REJECT - For TCP, send RST. For all other,
send "port unreachable" ICMP.
QUEUE - Send the request to a user-space
application using the QUEUE target.
CONTINUE - Pass the connection request past
any other rules that it might also
match (where the source or
destination zone in those rules is
a superset of the SOURCE or DEST
in this policy).
NONE - Assume that there will never be any
packets from this SOURCE
to this DEST. Shorewall will not set
up any infrastructure to handle such
packets and you may not have any
rules with this SOURCE and DEST in
the /etc/shorewall/rules file. If
such a packet _is_ received, the
result is undefined. NONE may not be
used if the SOURCE or DEST columns
contain the firewall zone ($FW) or
"all".
If the policy is DROP or REJECT then the policy should
be followed by ":" and one of the following:
a) The word "None" or "none". This causes any default
action defined in /etc/shorewall/shorewall.conf to
be omitted for this policy.
b) The name of an action (requires that USE_ACTIONS=Yes
in shorewall.conf). That action will be invoked
before the policy is enforced.
c) The name of a macro. The rules in that macro will
be applied before the policy is enforced. This
does not require USE_ACTIONS=Yes.
LOG LEVEL If supplied, each connection handled under the default
POLICY is logged at that level. If not supplied, no
log message is generated. See syslog.conf(5) for a
description of log levels.
Beginning with Shorewall version 1.3.12, you may
also specify ULOG (must be in upper case). This will
log to the ULOG target and sent to a separate log
through use of ulogd
(http://www.gnumonks.org/projects/ulogd).
If you don't want to log but need to specify the
following column, place "-" here.
LIMIT:BURST If passed, specifies the maximum TCP connection rate
and the size of an acceptable burst. If not specified,
TCP connections are not limited.
Example:
a) All connections from the local network to the internet are allowed
b) All connections from the internet are ignored but logged at syslog
level KERNEL.INFO.
d) All other connection requests are rejected and logged at level
KERNEL.INFO.
#SOURCE DEST POLICY LOG
# LEVEL
loc net ACCEPT
net all DROP info
#
# THE FOLLOWING POLICY MUST BE LAST
#
all all REJECT info
See http://shorewall.net/Documentation.htm#Policy for additional information.
################################################################################
/etc/shorewall/providers
This file is used to define additional routing tables. You will
want to define an additional table if:
- You have connections to more than one ISP or multiple connections
to the same ISP
- You run Squid as a transparent proxy on a host other than the
firewall.
To omit a column, enter "-".
Columns are:
NAME The provider name. Must be a valid shell variable name.
The names 'local', 'main', 'default' and 'unspec' are
reserved and may not be used as provider names.
NUMBER The provider number -- a number between 1 and 15
MARK A FWMARK value used in your /etc/shorewall/tcrules
file to direct packets to this provider.
If HIGH_ROUTE_MARKS=Yes in shorewall.conf, then the
value must be a multiple of 256 between 256 and 65280
or their hexadecimal equivalents (0x0100 and 0xff00
with the low-order byte of the value being zero).
Otherwise, the value must be between 1 and 255.
DUPLICATE The name of an existing table to duplicate. May be
'main' or the name of a previous provider.
INTERFACE The name of the network interface to the provider.
Must be listed in /etc/shorewall/interfaces.
GATEWAY The IP address of the provider's gateway router.
You can enter "detect" here and Shorewall will
attempt to detect the gateway automatically.
[ EXPERIMENTAL ] For PPP devices, you may omit this
column.
OPTIONS A comma-separated list selected from the following:
track If specified, inbound connections on this interface
are to be tracked so that responses may be routed back
out this same interface.
You want to specify 'track' if internet hosts will be
connecting to local servers through this provider.
balance The providers that have 'balance' specified will
get outbound traffic load-balanced among them. By
default, all interfaces with 'balance' specified
will have the same weight (1). You can change the
weight of an interface by specifiying balance=<weight>
where <weight> is the weight of the route out of
this interface.
loose Shorewall normally adds a routing rule for each
IP address on an interface which forces traffic
whose source is that IP address to be sent using
the routing table for that interface. Setting
'loose' prevents creation of such rules on this
interface.
optional
If the interface named in the INTERFACE column is not
up and configured with an IPv4 address then ignore
this provider.
COPY A comma-separated lists of other interfaces on your
firewall. Only makes sense when DUPLICATE is 'main'.
Only copy routes through INTERFACE and through
interfaces listed here. If you only wish to copy
routes through INTERFACE, enter 'none' here.
Example: You run squid in your DMZ on IP address 192.168.2.99. Your DMZ
interface is eth2
#NAME NUMBER MARK DUPLICATE INTERFACE GATEWAY OPTIONS
Squid 1 1 - eth2 192.168.2.99 -
Example:
eth0 connects to ISP 1. The IP address of eth0 is 206.124.146.176 and
the ISP's gateway router has IP address 206.124.146.254.
eth1 connects to ISP 2. The IP address of eth1 is 130.252.99.27 and the
ISP's gateway router has IP address 130.252.99.254.
eth2 connects to a local network.
#NAME NUMBER MARK DUPLICATE INTERFACE GATEWAY OPTIONS COPY
ISP1 1 1 main eth0 206.124.146.254 track,balance eth2
ISP2 2 2 main eth1 130.252.99.254 track,balance eth2
See http://www.shorewall.net/MultiISP.html for additional
information.
################################################################################
/etc/shorewall/proxyarp
This file is used to define Proxy ARP.
Columns are:
ADDRESS IP Address
INTERFACE Local interface where system is connected.
EXTERNAL External Interface to be used to access this system
HAVEROUTE If there is already a route from the firewall to
the host whose address is given, enter "Yes" or "yes"
in this column. Otherwise, entry "no", "No" or leave
the column empty and Shorewall will add the route for
you. If Shorewall adds the route,the route will be
persistent if the PERSISTENT column contains Yes;
otherwise, "shorewall stop" or "shorewall clear" will
delete the route.
PERSISTENT If HAVEROUTE is No or "no", then the value of this
column determines if the route added by Shorewall
persists after a "shorewall stop" or a "shorewall
clear". If this column contains "Yes" or "yes" then
the route persists; If the column is empty or contains
"No"or "no" then the route is deleted at "shorewall
stop" or "shorewall clear".
Example: Host with IP 155.186.235.6 is connected to
interface eth1 and we want hosts attached via eth0
to be able to access it using that address.
#ADDRESS INTERFACE EXTERNAL
155.186.235.6 eth1 eth0
See http://shorewall.net/ProxyARP.htm for additional information.
################################################################################
/etc/shorewall/rfc1918
Lists the subnetworks that are blocked by the 'norfc1918' interface
option.
The default list includes those IP addresses listed in RFC 1918.
DO NOT MODIFY THIS FILE. IF YOU NEED TO MAKE CHANGES, COPY THE FILE
TO /etc/shorewall AND MODIFY THE COPY.
Columns are:
SUBNETS A comma-separated list of subnet addresses
(host addresses also allowed as are IP
address ranges provided that your kernel and iptables
have iprange match support).
TARGET Where to send packets to/from this subnet
RETURN - let the packet be processed normally
DROP - silently drop the packet
logdrop - log then drop
By default, the RETURN target causes 'norfc1918' processing to cease
for a packet if the packet's source IP address matches the rule. Thus,
if you have:
SUBNETS TARGET
192.168.1.0/24 RETURN
then traffic from 192.168.1.4 to 10.0.3.9 will be accepted even though
you also have:
SUBNETS TARGET
10.0.0.0/8 logdrop
Setting RFC1918_STRICT=Yes in shorewall.conf will cause such traffic
to be logged and dropped since while the packet's source matches the
RETURN rule, the packet's destination matches the 'logdrop' rule.
################################################################################
/etc/shorewall/route_rules
Entries in this file cause traffic to be routed to one of the
providers listed in /etc/shorewall/providers.
Columns are:
SOURCE(optional)
An ip address (network or host) that
matches the source IP address in a packet.
May also be specified as an interface
name optionally followed by ":" and an
address. If the device 'lo' is specified,
the packet must originate from the firewall
itself.
DEST(optional) An ip address (network or host) that
matches the destination IP address in a packet.
If you choose to omit either SOURCE or DEST,
place "-" in that column. Note that you
may not omit both SOURCE and DEST.
PROVIDER The provider to route the traffic through.
May be expressed either as the provider name
or the provider number. May also be 'main'
or 254 for the main routing table. This can
be used in combination with VPN tunnels, see
example 2 below.
PRIORITY
The rule's priority which determines the order
in which the rules are processed.
1000-1999 Before Shorewall-generated
'MARK' rules
11000- 11999 After 'MARK' rules but before
Shorewall-generated rules for
ISP interfaces.
26000-26999 After ISP interface rules but
before 'default' rule.
Rules with equal priority are applied in
the order in which they appear in the file.
Example 1: You want all traffic coming in on eth1 to be routed to the ISP1
provider:
#SOURCE DEST PROVIDER PRIORITY
eth1 - ISP1 1000
Example 2: You use OpenVPN (routed setup /tunX) in combination with multiple
providers. In this case you have to set up a rule to ensure that
the OpenVPN traffic is routed back through the tunX interface(s)
rather than through any of the providers. 10.8.0.0/24 is the
subnet choosen in your OpenVPN configuration (server 10.8.0.0
255.255.255.0)
#SOURCE DEST PROVIDER PRIORITY
- 10.8.0.0/24 main 1000
For additional information, see
http://www.shorewall.net/MultiISP.html
################################################################################
/etc/shorewall/routestopped
This file is used to define the hosts that are accessible when the
firewall is stopped or when it is in the process of being
[re]started.
Columns are:
INTERFACE - Interface through which host(s) communicate with
the firewall
HOST(S) - (Optional) Comma-separated list of IP/subnet
addresses. If your kernel and iptables include
iprange match support, IP address ranges are also
allowed.
If left empty or supplied as "-",
0.0.0.0/0 is assumed.
OPTIONS - (Optional) A comma-separated list of
options. The currently-supported options are:
routeback - Set up a rule to ACCEPT traffic from
these hosts back to themselves.
source - Allow traffic from these hosts to ANY
destination. Without this option or the 'dest'
option, only traffic from this host to other
listed hosts (and the firewall) is allowed. If
'source' is specified then 'routeback' is redundant.
dest - Allow traffic to these hosts from ANY
source. Without this option or the 'source'
option, only traffic from this host to other
listed hosts (and the firewall) is allowed. If
'dest' is specified then 'routeback' is redundant.
critical - Allow traffic between the firewall and
these hosts throughout '[re]start', 'stop' and
'clear'. Specifying 'critical' on one or more
entries will cause your firewall to be "totally
open" for a brief window during each of those
operations.
NOTE: The 'source' and 'dest' options work best when used
in conjunction with ADMINISABSENTMINDED=Yes in
/etc/shorewall/shorewall.conf.
Example:
INTERFACE HOST(S) OPTIONS
eth2 192.168.1.0/24
eth0 192.0.2.44
br0 - routeback
eth3 - source
See http://shorewall.net/Documentation.htm#Routestopped and
http://shorewall.net/starting_and_stopping_shorewall.htm for additional
information.
################################################################################
/etc/shorewall/rules
Rules in this file govern connection establishment. Requests and
responses are automatically allowed using connection tracking. For any
particular (source,dest) pair of zones, the rules are evaluated in the
order in which they appear in this file and the first match is the one
that determines the disposition of the request.
In most places where an IP address or subnet is allowed, you
can preceed the address/subnet with "!" (e.g., !192.168.1.0/24) to
indicate that the rule matches all addresses except the address/subnet
given. Notice that no white space is permitted between "!" and the
address/subnet.
------------------------------------------------------------------------------
WARNING: If you masquerade or use SNAT from a local system to the internet,
you cannot use an ACCEPT rule to allow traffic from the internet to
that system. You *must* use a DNAT rule instead.
------------------------------------------------------------------------------
The rules file is divided into sections. Each section is introduced by
a "Section Header" which is a line beginning with SECTION followed by the
section name.
Sections are as follows and must appear in the order listed:
ESTABLISHED Packets in the ESTABLISHED state are processed
by rules in this section.
The only ACTIONs allowed in this section are
ACCEPT, DROP, REJECT, LOG and QUEUE
There is an implicit ACCEPT rule inserted
at the end of this section.
RELATED Packets in the RELATED state are processed by
rules in this section.
The only ACTIONs allowed in this section are
ACCEPT, DROP, REJECT, LOG and QUEUE
There is an implicit ACCEPT rule inserted
at the end of this section.
NEW Packets in the NEW and INVALID states are
processed by rules in this section.
Note: If you are not familiar with Netfilter to the point where you are
comfortable with the differences between the various connection
tracking states, then I suggest that you omit the ESTABLISHED and
RELATED sections and place all of your rules in the NEW section
(That's after the line that reads SECTION NEW').
WARNING: If you specify FASTACCEPT=Yes in shorewall.conf then the
ESTABLISHED and RELATED sections must be empty.
You may omit any section that you don't need. If no Section Headers appear
in the file then all rules are assumed to be in the NEW section.
Columns are:
ACTION ACCEPT, DROP, REJECT, DNAT, DNAT-, REDIRECT, CONTINUE,
LOG, QUEUE, COMMENT, a <macro>, or an <action>.
ACCEPT -- allow the connection request
ACCEPT+ -- like ACCEPT but also excludes the
connection from any subsequent
DNAT[-] or REDIRECT[-] rules
NONAT -- Excludes the connection from any
subsequent DNAT[-] or REDIRECT[-]
rules but doesn't generate a rule
to accept the traffic.
DROP -- ignore the request
REJECT -- disallow the request and return an
icmp-unreachable or an RST packet.
DNAT -- Forward the request to another
system (and optionally another
port).
DNAT- -- Advanced users only.
Like DNAT but only generates the
DNAT iptables rule and not
the companion ACCEPT rule.
SAME -- Similar to DNAT except that the
port may not be remapped and when
multiple server addresses are
listed, all requests from a given
remote system go to the same
server.
SAME- -- Advanced users only.
Like SAME but only generates the
NAT iptables rule and not
the companion ACCEPT rule.
REDIRECT -- Redirect the request to a local
port on the firewall.
REDIRECT-
-- Advanced users only.
Like REDIRET but only generates the
REDIRECT iptables rule and not
the companion ACCEPT rule.
CONTINUE -- (For experts only). Do not process
any of the following rules for this
(source zone,destination zone). If
The source and/or destination IP
address falls into a zone defined
later in /etc/shorewall/zones, this
connection request will be passed
to the rules defined for that
(those) zone(s).
LOG -- Simply log the packet and continue.
QUEUE -- Queue the packet to a user-space
application such as ftwall
(http://p2pwall.sf.net).
COMMENT -- the rest of the line will be attached
as a comment to the Netfilter rule(s)
generated by the following entres.
The comment will appear delimited by
"/* ... */" in the output of
"shorewall show <chain>". To stop
the comment from being attached to
further rules, simply include
COMMENT on a line by itself.
<action> -- The name of an action defined in
/etc/shorewall/actions or in
/usr/share/shorewall/actions.std.
<macro> -- The name of a macro defined in a
file named macro.<macro-name>. If
the macro accepts an action
parameter (Look at the macro
source to see if it has PARAM in
the TARGET column) then the macro
name is followed by "/" and the
action (ACCEPT, DROP, REJECT, ...)
to be substituted for the
parameter. Example: FTP/ACCEPT.
The ACTION may optionally be followed
by ":" and a syslog log level (e.g, REJECT:info or
DNAT:debug). This causes the packet to be
logged at the specified level.
If the ACTION names an action defined in
/etc/shorewall/actions or in
/usr/share/shorewall/actions.std then:
- If the log level is followed by "!' then all rules
in the action are logged at the log level.
- If the log level is not followed by "!" then only
those rules in the action that do not specify
logging are logged at the specified level.
- The special log level 'none!' suppresses logging
by the action.
You may also specify ULOG (must be in upper case) as a
log level.This will log to the ULOG target for routing
to a separate log through use of ulogd
(http://www.gnumonks.org/projects/ulogd).
Actions specifying logging may be followed by a
log tag (a string of alphanumeric characters)
are appended to the string generated by the
LOGPREFIX (in /etc/shorewall/shorewall.conf).
Example: ACCEPT:info:ftp would include 'ftp '
at the end of the log prefix generated by the
LOGPREFIX setting.
SOURCE Source hosts to which the rule applies. May be a zone
defined in /etc/shorewall/zones, $FW to indicate the
firewall itself, "all", "all+", "all-", "all+-" or
"none".
When "none" is used either in the SOURCE or DEST
column, the rule is ignored.
"all" means "All Zones", including the firewall itself.
"all-" means "All Zones, except the firewall itself".
When "all[-]" is used either in the SOURCE or DEST column
intra-zone traffic is not affected. When "all+[-]" is
"used, intra-zone traffic is affected.
Except when "all[+][-]" is specified, clients may be
further restricted to a list of subnets and/or hosts by
appending ":" and a comma-separated list of subnets
and/or hosts. Hosts may be specified by IP or MAC
address; mac addresses must begin with "~" and must use
"-" as a separator.
Hosts may be specified as an IP address range using the
syntax <low address>-<high address>. This requires that
your kernel and iptables contain iprange match support.
If you kernel and iptables have ipset match support
then you may give the name of an ipset prefaced by "+".
The ipset name may be optionally followed by a number
from 1 to 6 enclosed in square brackets ([]) to
indicate the number of levels of source bindings to be
matched.
dmz:192.168.2.2 Host 192.168.2.2 in the DMZ
net:155.186.235.0/24 Subnet 155.186.235.0/24 on the
Internet
loc:192.168.1.1,192.168.1.2
Hosts 192.168.1.1 and
192.168.1.2 in the local zone.
loc:~00-A0-C9-15-39-78 Host in the local zone with
MAC address 00:A0:C9:15:39:78.
net:192.0.2.11-192.0.2.17
Hosts 192.0.2.11-192.0.2.17 in
the net zone.
Alternatively, clients may be specified by interface
by appending ":" to the zone name followed by the
interface name. For example, loc:eth1 specifies a
client that communicates with the firewall system
through eth1. This may be optionally followed by
another colon (":") and an IP/MAC/subnet address
as described above (e.g., loc:eth1:192.168.1.5).
DEST Location of Server. May be a zone defined in
/etc/shorewall/zones, $FW to indicate the firewall
itself, "all". "all+" or "none".
When "none" is used either in the SOURCE or DEST
column, the rule is ignored.
When "all" is used either in the SOURCE or DEST column
intra-zone traffic is not affected. When "all+" is
used, intra-zone traffic is affected.
Except when "all[+]" is specified, the server may be
further restricted to a particular subnet, host or
interface by appending ":" and the subnet, host or
interface. See above.
Restrictions:
1. MAC addresses are not allowed.
2. In DNAT rules, only IP addresses are
allowed; no FQDNs or subnet addresses
are permitted.
3. You may not specify both an interface and
an address.
Like in the SOURCE column, you may specify a range of
up to 256 IP addresses using the syntax
<first ip>-<last ip>. When the ACTION is DNAT or DNAT-,
the connections will be assigned to addresses in the
range in a round-robin fashion.
If you kernel and iptables have ipset match support
then you may give the name of an ipset prefaced by "+".
The ipset name may be optionally followed by a number
from 1 to 6 enclosed in square brackets ([]) to
indicate the number of levels of destination bindings
to be matched. Only one of the SOURCE and DEST columns
may specify an ipset name.
The port that the server is listening on may be
included and separated from the server's IP address by
":". If omitted, the firewall will not modifiy the
destination port. A destination port may only be
included if the ACTION is DNAT or REDIRECT.
Example: loc:192.168.1.3:3128 specifies a local
server at IP address 192.168.1.3 and listening on port
3128. The port number MUST be specified as an integer
and not as a name from /etc/services.
if the ACTION is REDIRECT, this column needs only to
contain the port number on the firewall that the
request should be redirected to.
PROTO Protocol - Must be "tcp", "tcp:syn", "udp", "icmp",
"ipp2p", "ipp2p:udp", "ipp2p:all" a number, or "all".
"ipp2p*" requires ipp2p match support in your kernel
and iptables.
"tcp:syn" implies "tcp" plus the SYN flag must be
set and the RST,ACK and FIN flags must be reset.
DEST PORT(S) Destination Ports. A comma-separated list of Port
names (from /etc/services), port numbers or port
ranges; if the protocol is "icmp", this column is
interpreted as the destination icmp-type(s).
If the protocol is ipp2p, this column is interpreted
as an ipp2p option without the leading "--" (example
"bit" for bit-torrent). If no port is given, "ipp2p" is
assumed.
A port range is expressed as <low port>:<high port>.
This column is ignored if PROTOCOL = all but must be
entered if any of the following ields are supplied.
In that case, it is suggested that this field contain
"-"
If your kernel contains multi-port match support, then
only a single Netfilter rule will be generated if in
this list and the CLIENT PORT(S) list below:
1. There are 15 or less ports listed.
2. No port ranges are included.
Otherwise, a separate rule will be generated for each
port.
SOURCE PORT(S) (Optional) Port(s) used by the client. If omitted,
any source port is acceptable. Specified as a comma-
separated list of port names, port numbers or port
ranges.
If you don't want to restrict client ports but need to
specify an ORIGINAL DEST in the next column, then
place "-" in this column.
If your kernel contains multi-port match support, then
only a single Netfilter rule will be generated if in
this list and the DEST PORT(S) list above:
1. There are 15 or less ports listed.
2. No port ranges are included.
Otherwise, a separate rule will be generated for each
port.
ORIGINAL DEST (0ptional) -- If ACTION is DNAT[-] or REDIRECT[-]
then if included and different from the IP
address given in the SERVER column, this is an address
on some interface on the firewall and connections to
that address will be forwarded to the IP and port
specified in the DEST column.
A comma-separated list of addresses may also be used.
This is usually most useful with the REDIRECT target
where you want to redirect traffic destined for
particular set of hosts.
Finally, if the list of addresses begins with "!" then
the rule will be followed only if the original
destination address in the connection request does not
match any of the addresses listed.
For other actions, this column may be included and may
contain one or more addresses (host or network)
separated by commas. Address ranges are not allowed.
When this column is supplied, rules are generated
that require that the original destination address
matches one of the listed addresses. This feature is
most useful when you want to generate a filter rule
that corresponds to a DNAT- or REDIRECT- rule. In this
usage, the list of addresses should not begin with "!".
See http://shorewall.net/PortKnocking.html for an
example of using an entry in this column with a
user-defined action rule.
RATE LIMIT You may rate-limit the rule by placing a value in
this colume:
<rate>/<interval>[:<burst>]
where <rate> is the number of connections per
<interval> ("sec" or "min") and <burst> is the
largest burst permitted. If no <burst> is given,
a value of 5 is assumed. There may be no
no whitespace embedded in the specification.
Example: 10/sec:20
USER/GROUP This column may only be non-empty if the SOURCE is
the firewall itself.
The column may contain:
[!][<user name or number>][:<group name or number>][+<program name>]
When this column is non-empty, the rule applies only
if the program generating the output is running under
the effective <user> and/or <group> specified (or is
NOT running under that id if "!" is given).
Examples:
joe #program must be run by joe
:kids #program must be run by a member of
#the 'kids' group
!:kids #program must not be run by a member
#of the 'kids' group
+upnpd #program named upnpd (This feature was
#removed from Netfilter in kernel
#version 2.6.14).
Example: Accept SMTP requests from the DMZ to the internet
#ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL
# PORT PORT(S) DEST
ACCEPT dmz net tcp smtp
Example: Forward all ssh and http connection requests from the
internet to local system 192.168.1.3
#ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL
# PORT PORT(S) DEST
DNAT net loc:192.168.1.3 tcp ssh,http
Example: Forward all http connection requests from the internet
to local system 192.168.1.3 with a limit of 3 per second and
a maximum burst of 10
#ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL RATE
# PORT PORT(S) DEST LIMIT
DNAT net loc:192.168.1.3 tcp http - - 3/sec:10
Example: Redirect all locally-originating www connection requests to
port 3128 on the firewall (Squid running on the firewall
system) except when the destination address is 192.168.2.2
#ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL
# PORT PORT(S) DEST
REDIRECT loc 3128 tcp www - !192.168.2.2
Example: All http requests from the internet to address
130.252.100.69 are to be forwarded to 192.168.1.3
#ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL
# PORT PORT(S) DEST
DNAT net loc:192.168.1.3 tcp 80 - 130.252.100.69
Example: You want to accept SSH connections to your firewall only
from internet IP addresses 130.252.100.69 and 130.252.100.70
#ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL
# PORT PORT(S) DEST
ACCEPT net:130.252.100.69,130.252.100.70 $FW \
tcp 22
See http://www.shorewall.net/Documentation.htm#Rules for additional
information.
################################################################################
Based on tc4shorewall version 0.5 by Arne Bernin
/etc/shorewall/tcclasses
Define the classes used for traffic shaping in this file.
A note on the rate/bandwidth definitions used in this file:
- don't use a space between the integer value and
the unit: 30kbit is valid while 30 kbit is NOT.
- you can use one of the following units:
kbps Kilobytes per second
mbps Megabytes per second
kbit Kilobits per second
mbit Megabits per second
bps or a
bare number Bytes per second
- if you want the values to be calculated for you depending
on the output bandwidth setting defined for an interface
in tcdevices, you can use expressions like the following:
full/3 causes the bandwidth to be calculated
as 3 of the the full outgoing
speed that is defined.
full*9/10 will set this bandwidth to 9/10 of
the full bandwidth
DO NOT add a unit to the rate if it is calculated !
Columns are:
INTERFACE Name of interface. Each interface may be listed only
once in this file. You may NOT specify the name of
an alias (e.g., eth0:0) here; see
http://www.shorewall.net/FAQ.htm#faq18
You may NOT specify wildcards here, e.g. if you
have multiple ppp interfaces, you need to put
them all in here!
Please note that you can only use interface names
in here that have a bandwidth defined in the tcdevices
file
MARK The mark value which is an integer in the range 1-255.
You define this marks in the tcrules file, marking
the traffic you want to fit in the classes defined
in here.
You can use the same marks for different interfaces.
RATE The minimum bandwidth this class should get,
when the traffic load rises. If the sum of the rates
in this column exceed the INTERFACE's OUT-BANDWIDTH,
then the OUT-BANDWIDTH limit may not be honored.
CEIL The maximum bandwidth this class is allowed to use
when the link is idle. Useful if you have traffic
which can get full speed when more needed services
(e.g. ssh) are not used.
You can use the value "full" in here for setting
the maximum bandwidth to the defined output bandwidth
of that interface.
PRIORITY The priority in which classes will be serviced by
the packet shaping scheduler and also the priority
in which bandwidth in excess of the rate will be
given to each class.
Higher priority classes will experience less delay
since they are serviced first. Priority values
are serviced in ascending order (e.g. 0 is higher
priority than 1).
Classes may be set to the same priority, in which
case they will be serviced as equals.
OPTIONS A comma-separated list of options including the
following:
default - this is the default class for that
interface where all traffic should go,
that is not classified otherwise.
NOTE: defining default for exactly one
class per interface is mandatory!
tos=0x<value>[/0x<mask>] (mask defaults to 0xff)
- this lets you define a classifier
for the given <value>/<mask>
combination of the IP packet's
TOS/Precedence/DiffSrv octet (aka the
TOS byte). Please note, classifiers
override all mark settings, so if you
define a classifer for a class, all
traffic having that mark will go in it
regardless of any mark set on the
packet by a firewall/mangle filter.
NOTE: multiple tos= statements may be
applied per class and per interface,
but a given value/mask pair is valid
for only ONE class per interface.
tos-<tosname> - aliases for the following TOS octet
value and mask encodings. TOS
encodings of the "TOS byte" have been
deprecated in favor of diffserve
classes, but programs like ssh,
rlogin, and ftp still use them.
tos-minimize-delay 0x10/0x10
tos-maximize-throughput 0x08/0x08
tos-maximize-reliability 0x04/0x04
tos-minimize-cost 0x02/0x02
tos-normal-service 0x00/0x1e
NOTE: each of this options is only
valid for ONE class per interface.
tcp-ack - if defined causes an tc filter to
be created that puts all tcp ack
packets on that interface that have
an size of <=64 Bytes to go in this
class. This is useful for speeding up
downloads. Please note that the size
of the ack packets is limited to 64
bytes as some applications (p2p for
example) use to make every packet an
ack packet which would cause them
all into here. We want only packets
WITHOUT payload to match, so the size
limit.
NOTE: This option is only valid for
ONE class per interface.
Example 1: Suppose you are using PPP over Ethernet (DSL)
and ppp0 is the interface for this. You have 4 classes
here, the first you can use for voice over IP
traffic, the second interactive traffic (e.g.
ssh/telnet but not scp), the third will be for all
unclassified traffic, and the forth is for low
priority traffic (e.g. peer-to-peer).
The voice traffic in the first class will be
guaranteed a minimum of 100kbps and always be
serviced first (because of the low priority number,
giving less delay) and will be granted excess
bandwidth (up to 180kbps, the class ceiling) first,
before any other traffic. A single VOIP stream,
depending upon codecs, after encapsulation, can take
up to 80kbps on a PPOE/DSL link, so we pad a little
bit just in case. (TOS byte values 0xb8 and 0x68
are DiffServ classes EF and AFF3-1 respectively and
are often used by VOIP devices).
Interactive traffic (tos-minimum-delay) and
TCP acks (and ICMP echo traffic if you use the example
in tcrules) and any packet with a mark of 2 will be
guaranteed 1/4 of the link bandwidth, and may extend
up to full speed of the link.
Unclassified traffic and packets marked as 3 will be
guaranteed 1/4th of the link bandwidth, and may extend
to the full speed of the link.
Packets marked with 4 will be treated as low priority
packets. (The tcrules example marks p2p traffic as
such.) If the link is congested, they're only
guaranteed 1/8th of the speed, and even if the link is
empty, can only expand to 80% of link bandwidth just
as a precaution in case there are upstream queues we
didn't account for. This is the last class to get
additional bandwidth and the last to get serviced by
the scheduler because of the low priority.
ppp0 1 100kbit 180kbit 1 tos=0x68/0xfc,tos=0xb8/0xfc
ppp0 2 full/4 full 2 tcp-ack,tos-minimize-delay
ppp0 3 full/4 full 3 default
ppp0 4 full/8 full*8/10 4
See http://shorewall.net/traffic_shaping.htm for additional information.
################################################################################
Based on tc4shorewall version 0.5 by Arne Bernin
/etc/shorewall/tcdevices
Entries in this file define the bandwidth for interfaces
on which you want traffic shaping to be enabled.
If you do not plan to use traffic shaping for a device,
don't put it in here as it limits the troughput of that
device to the limits you set here.
Columns are:
INTERFACE Name of interface. Each interface may be listed only
once in this file. You may NOT specify the name of
an alias (e.g., eth0:0) here; see
http://www.shorewall.net/FAQ.htm#faq18
You man NOT specify wildcards here, e.g. if you
have multiple ppp interfaces, you need to put
them all in here!
If the device doesn't exist, a warning message will
be issued during "shorewall [re]start" and "shorewall
refresh" and traffic shaping configuration will be
skipped for that device.
IN-BANDWIDTH The incoming Bandwidth of that interface. Please
note that you are not able to do traffic shaping
on incoming traffic, as the traffic is already
received before you could do so. But this allows
you to define the maximum traffic allowed for
this interface in total, if the rate is exceeded,
the packets are dropped.
You want this mainly if you have a DSL or Cable
connection to avoid queuing at your providers side.
If you don't want any traffic to be dropped, set this
to a value to zero in which case Shorewall will not
create an ingress qdisc.
Use kbit or kbps(for Kilobytes per second) for
speed, and make sure there is NO space between the
number and the unit.
OUT-BANDWIDTH The outgoing Bandwidth of that interface.
This is the maximum speed you connection can handle.
It is also the speed you can refer as "full" if
you define the tc classes.
Outgoing traffic above this rate will be dropped.
Use kbit or kbps(for Kilobytes per second) for
speed, and make sure there is NO space between the
number and the unit.
Example 1: Suppose you are using PPP over Ethernet (DSL)
and ppp0 is the interface for this. The
device has an outgoing bandwidth of 500kbit and an
incoming bandwidth of 6000kbit
ppp0 6000kbit 500kbit
See http://shorewall.net/traffic_shaping.htm for additional information.
################################################################################
/etc/shorewall/tcrules
Entries in this file cause packets to be marked as a means of
classifying them for traffic control or policy routing.
I M P O R T A N T ! ! ! !
Unlike rules in the /etc/shorewall/rules file, evaluation
of rules in this file will continue after a match. So the
final mark for each packet will be the one assigned by the
LAST tcrule that matches.
If you use multiple internet providers with the 'track' option,
in /etc/shorewall/providers be sure to read the restrictions at
http://shorewall.net/MultiISP.html.
Columns are:
MARK/ a) A mark value which is an integer in the range 1-255.
CLASSIFY
Normally will set the mark value. If preceded by
a vertical bar ("|"), the mark value will be
logically ORed with the current mark value to
produce a new mark value. If preceded by an
ampersand ("&"), will be logically ANDed with the
current mark value to produce a new mark value.
Both "|" and "&" require Extended MARK Target
support in your kernel and iptables; neither may
be used with connection marks (see below).
If HIGH_ROUTE_MARKS=Yes in shorewall.conf then
you may also specify a value in the range 0x0100-
0xFF00 with the low-order byte being zero. Such
values may only be used in the PREROUTING chain
(value followed by :F or you have set
MARK_IN_FORWARD_CHAIN=Yes in shorewall conf and have
not followed the value with :P) or the OUTPUT chain
(SOURCE is $FW).
May optionally be followed by ":P" or ":F"
where ":P" indicates that marking should occur in
the PREROUTING chain and ":F" indicates that marking
should occur in the FORWARD chain. If neither
":P" nor ":F" follow the mark value then the chain
is determined by the setting of
MARK_IN_FORWARD_CHAIN in
/etc/shorewall/shorewall.conf.
If your kernel and iptables include CONNMARK support
then you can also mark the connection rather than
the packet.
The mark value may be optionally followed by "/"
and a mask value (used to determine those bits of
the connection mark to actually be set). The
mark and optional mask are then followed by one of:
C - Mark the connection in the chain determined
by the setting of MARK_IN_FORWARD_CHAIN
CF: Mark the connection in the FORWARD chain
CP: Mark the connection in the PREROUTING
chain.
b) A classification (classid) of the form
<major>:<minor> where <major> and <minor> are
integers. Corresponds to the 'class' specification
in these traffic shaping modules:
- atm
- cbq
- dsmark
- pfifo_fast
- htb
- prio
Classification occurs in the POSTROUTING chain except
when the SOURCE is $FW[:<address>] in which case
marking occurs in the OUTPUT chain.
c) RESTORE[/mask] -- restore the packet's mark from the
connection's mark using the supplied mask if any.
Your kernel and iptables must include CONNMARK
support.
As in a) above, may be followed by ":P" or ":F
c) SAVE[/mask] -- save the packet's mark to the
connection's mark using the supplied mask if any.
Your kernel and iptables must include CONNMARK
support.
As in a) above, may be followed by ":P" or ":F
d) CONTINUE -- don't process any more marking rules in
the table.
As in a) above, may be followed by ":P" or ":F".
e) COMMENT -- the rest of the line will be attached as
a comment to the Netfilter rule(s) generated by the
following entries. The comment will appear delimited
by "/* ... */" in the output of "shorewall show
mangle"
To stop the comment from being attached to further
rules, simply include COMMENT on a line by itself.
SOURCE Source of the packet. A comma-separated list of
interface names, IP addresses, MAC addresses and/or
subnets for packets being routed through a common path.
List elements may also consist of an interface name
followed by ":" and an address
(e.g., eth1:192.168.1.0/24). For example, all packets
for connections masqueraded to eth0 from other
interfaces can be matched in a single rule with
several alternative SOURCE criteria. However, a
connection whose packets gets to eth0 in a
different way, e.g., direct from the firewall itself,
needs a different rule.
Accordingly, use $FW in its own separate rule for
packets originating on the firewall. In such a rule,
the MARK column may NOT specify either ":P" or ":F"
because marking for firewall-originated packets
always occurs in the OUTPUT chain.
MAC addresses must be prefixed with "~" and use
"-" as a separator.
Example: ~00-A0-C9-15-39-78
DEST Destination of the packet. Comma separated list of
IP addresses and/or subnets. If your kernel and
iptables include iprange match support, IP address
ranges are also allowed. List elements may also
consist of an interface name followed by ":" and an
address (e.g., eth1:192.168.1.0/24).
If the MARK column specificies a classification of
the form <major>:<minor> then this column may also
contain an interface name.
PROTO Protocol - Must be "tcp", "udp", "icmp", "ipp2p",
"ipp2p:udp", "ipp2p:all" a number, or "all".
"ipp2p" requires ipp2p match support in your kernel
and iptables.
PORT(S) Destination Ports. A comma-separated list of Port
names (from /etc/services), port numbers or port
ranges; if the protocol is "icmp", this column is
interpreted as the destination icmp-type(s).
If the protocol is ipp2p, this column is interpreted
as an ipp2p option without the leading "--" (example
"bit" for bit-torrent). If no PORT is given, "ipp2p" is
assumed.
This column is ignored if PROTOCOL = all but must be
entered if any of the following field is supplied.
In that case, it is suggested that this field contain
"-"
SOURCE PORT(S) (Optional) Source port(s). If omitted,
any source port is acceptable. Specified as a comma-
separated list of port names, port numbers or port
ranges.
USER This column may only be non-empty if the SOURCE is
the firewall itself.
When this column is non-empty, the rule applies only
if the program generating the output is running under
the effective user and/or group.
It may contain :
[<user name or number>]:[<group name or number>][+<program name>]
The colon is optionnal when specifying only a user
or a program name.
Examples : john: , john , :users , john:users ,
+mozilla-bin (Support for program names
was removed from Netfilter in Kernel
version 2.6.14).
TEST Defines a test on the existing packet or connection
mark. The rule will match only if the test returns
true. Tests have the format [!]<value>[/<mask>][:C]
Where:
! Inverts the test (not equal)
<value> Value of the packet or connection mark.
<mask> A mask to be applied to the mark before
testing
:C Designates a connection mark. If
omitted, the packet mark's value is
tested.
If you don't want to define a test but need to specify
anything in the following columns, place a "-" in this
field.
LENGTH (Optional) Packet Length. This field, if present
allow you to match the length of a packet against
a specific value or range of values. You must have
iptables length support for this to work.
A range is specified in the form <min>:<max>
where either <min> or <max> (but not both) may be
omitted. If <min> is omitted, then 0 is assumed; if
<max> is omitted, than any packet that is <min> or
longer will match.
Examples: 1024, 64:1500, :100 (packet of length
100 bytes or less)
If you don't want to define a test but need to specify
anything in the following columns, place a "-" in this
field.
TOS Type of service. Either a standard name, or a numeric
value to match.
Minimize-Delay (16)
Maximize-Throughput (8)
Maximize-Reliability (4)
Minimize-Cost (2)
Normal-Service (0)
Example 1:
Mark all ICMP echo traffic with packet mark 1.
Mark all peer to peer traffic with packet mark 4.
This is a little more complex than otherwise expected. Since
the ipp2p module is unable to determine all packets in a
connection are P2P packets, we mark the entire connection as
P2P if any of the packets are determined to match.
We assume packet/connection mark 0 to means unclassified.
1 0.0.0.0/0 0.0.0.0/0 icmp echo-request
1 0.0.0.0/0 0.0.0.0/0 icmp echo-reply
RESTORE 0.0.0.0/0 0.0.0.0/0 all - - - 0
CONTINUE 0.0.0.0/0 0.0.0.0/0 all - - - !0
4 0.0.0.0/0 0.0.0.0/0 ipp2p:all
SAVE 0.0.0.0/0 0.0.0.0/0 all - - - !0
"If a packet hasn't been classifed (packet mark is 0), copy
the connection mark to the packet mark. If the packet mark
is set, we're done. If the packet is P2P, set the packet
mark to 4. If the packet mark has been set, save it to the
connection mark."
See http://shorewall.net/traffic_shaping.htm for additional information.
For usage in selecting among multiple ISPs, see
http://shorewall.net/MultiISP.html
################################################################################
/etc/shorewall/tos
This file defines rules for setting Type Of Service (TOS)
Columns are:
SOURCE Name of a zone declared in /etc/shorewall/zones, "all"
or $FW.
If not "all" or $FW, may optionally be followed by
":" and an IP address, a MAC address, a subnet
specification or the name of an interface.
Example: loc:192.168.2.3
MAC addresses must be prefixed with "~" and use
"-" as a separator.
Example: ~00-A0-C9-15-39-78
DEST Name of a zone declared in /etc/shorewall/zones, "all"
or $FW.
If not "all" or $FW, may optionally be followed by
":" and an IP address or a subnet specification
Example: loc:192.168.2.3
PROTOCOL Protocol.
SOURCE PORTS Source port or port range. If all ports, use "-".
DEST PORTS Destination port or port range. If all ports, use "-"
TOS Type of service. Must be one of the following:
Minimize-Delay (16)
Maximize-Throughput (8)
Maximize-Reliability (4)
Minimize-Cost (2)
Normal-Service (0)
See http://shorewall.net/Documentation.htm#TOS for additional
information.
################################################################################
/etc/shorewall/tunnels
This file defines IPSEC, GRE, IPIP and OPENVPN tunnels.
IPIP, GRE and OPENVPN tunnels must be configured on the
firewall/gateway itself. IPSEC endpoints may be defined
on the firewall/gateway or on an internal system.
The columns are:
TYPE -- must start in column 1 and be "ipsec", "ipsecnat",
"ipip", "gre", "6to4", "pptpclient", "pptpserver",
"openvpn", "openvpnclient", "openvpnserver" or
"generic"
If the type is "ipsec" or "ipsecnat", it may be
followed by ":noah" to indicate that the Authentication
Header protocol (51) is not used by the tunnel.
If type is "openvpn", "openvpnclient" or
"openvpnserver" it may optionally be followed by ":"
and "tcp" or "udp" to specify the protocol to be
used. If not specified, "udp" is assumed.
If type is "openvpn", "openvpnclient" or
"openvpnserver" it may optionally be followed
by ":" and the port number used by the tunnel. if no
":" and port number are included, then the default port
of 1194 will be used. . Where both the protocol and port
are specified, the protocol must be given first (e.g.,
openvpn:tcp:4444).
If type is "generic", it must be followed by ":" and
a protocol name (from /etc/protocols) or a protocol
number. If the protocol is "tcp" or "udp" (6 or 17),
then it may optionally be followed by ":" and a
port number.
ZONE -- The zone of the physical interface through which
tunnel traffic passes. This is normally your internet
zone.
GATEWAY -- The IP address of the remote tunnel gateway. If the
remote gateway has no fixed address (Road Warrior)
then specify the gateway as 0.0.0.0/0. May be
specified as a network address and if your kernel and
iptables include iprange match support then IP address
ranges are also allowed.
GATEWAY
ZONES -- Optional. If the gateway system specified in the third
column is a standalone host then this column should
contain a comma-separated list of the names of the
zones that the host might be in. This column only
applies to IPSEC tunnels where it enables ISAKMP
traffic to flow through the tunnel to the remote
gateway.
Example 1:
IPSec tunnel. The remote gateway is 4.33.99.124 and
the remote subnet is 192.168.9.0/24. The tunnel does
not use the AH protocol
ipsec:noah net 4.33.99.124
Example 2:
Road Warrior (LapTop that may connect from anywhere)
where the "gw" zone is used to represent the remote
LapTop.
ipsec net 0.0.0.0/0 gw
Example 3:
Host 4.33.99.124 is a standalone system connected
via an ipsec tunnel to the firewall system. The host
is in zone gw.
ipsec net 4.33.99.124 gw
Example 4:
Road Warriors that may belong to zones vpn1, vpn2 or
vpn3. The FreeS/Wan _updown script will add the
host to the appropriate zone using the "shorewall add"
command on connect and will remove the host from the
zone at disconnect time.
ipsec net 0.0.0.0/0 vpn1,vpn2,vpn3
Example 5:
You run the Linux PPTP client on your firewall and
connect to server 192.0.2.221.
pptpclient net 192.0.2.221
Example 6:
You run a PPTP server on your firewall.
pptpserver net
Example 7:
OPENVPN tunnel. The remote gateway is 4.33.99.124 and
openvpn uses port 7777.
openvpn:7777 net 4.33.99.124
Example 8:
You have a tunnel that is not one of the supported
types. Your tunnel uses UDP port 4444. The other end
of the tunnel is 4.3.99.124.
generic:udp:4444 net 4.3.99.124
See http://shorewall.net/Documentation.htm#Tunnels for additional
information.
################################################################################
/etc/shorewall/zones
This file declares your network zones. You specify the hosts in
each zone through entries in /etc/shorewall/interfaces or
/etc/shorewall/hosts.
WARNING: The format of this file changed in Shorewall 3.0.0. You can
continue to use your old records provided that you set
IPSECFILE=ipsec in /etc/shorewall/shorewall.conf. This will
signal Shorewall that the IPSEC-related zone options are
still specified in /etc/shorewall/ipsec rather than in this
file.
To use records in the format described below, you must have
IPSECFILE=zones specified in /etc/shorewall/shorewall.conf
AND YOU MUST NOT SET THE 'FW' VARIABLE IN THAT FILE!!!!!
Columns are:
ZONE Short name of the zone. The names "all" and "none" are reserved
and may not be used as zone names. The maximum length of a
zone name is determined by the setting of the LOGFORMAT option
in shorewall.conf. With the default LOGFORMAT, zone names can
be at most 5 characters long.
Where a zone is nested in one or more other zones,
you may follow the (sub)zone name by ":" and a
comma-separated list of the parent zones. The parent
zones must have been defined in earlier records in this
file.
Example:
#ZONE TYPE OPTIONS
a ipv4
b ipv4
c:a,b ipv4
Currently, Shorewall uses this information to reorder the
zone list so that parent zones appear after their subzones in
the list. The IMPLICIT_CONTINUE option in shorewall.conf can
also create implicit CONTINUE policies to/from the subzone.
In the future, Shorewall may make additional use
of nesting information.
TYPE ipv4 - This is the standard Shorewall zone type and is the
default if you leave this column empty or if you enter
"-" in the column. Communication with some zone hosts
may be encrypted. Encrypted hosts are designated using
the 'ipsec'option in /etc/shorewall/hosts.
ipsec - Communication with all zone hosts is encrypted
Your kernel and iptables must include policy
match support.
firewall
- Designates the firewall itself. You must have
exactly one 'firewall' zone. No options are
permitted with a 'firewall' zone. The name that you
enter in the ZONE column will be stored in the shell
variable $FW which you may use in other configuration
files to designate the firewall zone.
OPTIONS, A comma-separated list of options as follows:
IN OPTIONS,
OUT OPTIONS reqid=<number> where <number> is specified
using setkey(8) using the 'unique:<number>
option for the SPD level.
spi=<number> where <number> is the SPI of
the SA used to encrypt/decrypt packets.
proto=ah|esp|ipcomp
mss=<number> (sets the MSS field in TCP packets)
mode=transport|tunnel
tunnel-src=<address>[/<mask>] (only
available with mode=tunnel)
tunnel-dst=<address>[/<mask>] (only
available with mode=tunnel)
strict Means that packets must match all rules.
next Separates rules; can only be used with
strict
Example:
mode=transport,reqid=44
The options in the OPTIONS column are applied to both incoming
and outgoing traffic. The IN OPTIONS are applied to incoming
traffic (in addition to OPTIONS) and the OUT OPTIONS are
applied to outgoing traffic.
If you wish to leave a column empty but need to make an entry
in a following column, use "-".
------------------------------------------------------------------------------
Example zones:
You have a three interface firewall with internet, local and DMZ
interfaces.
#ZONE TYPE OPTIONS IN OUT
# OPTIONS OPTIONS
fw firewall
net ipv4
loc ipv4
dmz ipv4
For more information, see http://www.shorewall.net/Documentation.htm#Zones
################################################################################