shorewall6.conf5shorewall6.confShorewall6 global configuration file/etc/shorewall6/shorewall6.confDescriptionThis file sets options that apply to Shorewall6 as a whole.The file consists of Shell comments (lines beginning with '#'),
blank lines and assignment statements
(variable=value). If the
value contains shell metacharacters or white-space,
then it must be enclosed in quotes. Example:
LOG_LEVEL="NFLOG(1,0,1)".OPTIONSMany options have as their value a log-level.
Log levels are a method of describing to syslog (8) the importance of a
message and a number of parameters in this file have log levels as their
value.These levels are defined by syslog and are used to determine the
destination of the messages through entries in /etc/syslog.conf (5). The
syslog documentation refers to these as "priorities"; Netfilter calls them
"levels" and Shorewall6 also uses that term.Valid levels are: 7 debug
6 info
5 notice
4 warning
3 err
2 crit
1 alert
0 emergFor most Shorewall6 logging, a level of 6 (info) is appropriate.
Shorewall6 log messages are generated by NetFilter and are logged using
facility 'kern' and the level that you specifify. If you are unsure of the
level to choose, 6 (info) is a safe bet. You may specify levels by name or
by number.If you have built your kernel with NFLOG target support, you may
also specify a log level of NFLOG (must be all caps). Rather than log its
messages to syslogd, Shorewall6 will direct netfilter to log the messages
via the NFLOG target which will send them to a process called 'ulogd'.
ulogd is available with most Linux distributions (although it probably
isn't installed by default). Ulogd is also available from http://www.netfilter.org/projects/ulogd/index.html
and can be configured to log all Shorewall6 message to their own log
fileThe following options may be set in shorewall6.conf.ACCEPT_DEFAULT={action[(parameters)][:level]|none}DROP_DEFAULT={action[(parameters)][:level]|none}NFQUEUE_DEFAULT={action[(parameters)][:level]|none}QUEUE_DEFAULT={action[(parameters)][:level]|none}REJECT_DEFAULT={action[(parameters)][:level]|none}DROP_DEFAULT describes the rules to be applied before a
connection request is dropped by a DROP policy; REJECT_DEFAULT
describes the rules to be applied if a connection request is
rejected by a REJECT policy. The other three are similar for ACCEPT,
QUEUE and NFQUEUE policies.The value applied to these may be:a) The name of an action. The
name may optionally be followed by a comma-separated list of
parameters enclosed in parentheses if the specified action accepts
parameters (e.g., 'Drop(audit)').c) None or noneThe default values are:DROP_DEFAULT="Drop"REJECT_DEFAULT="Reject"ACCEPT_DEFAULT="none"QUEUE_DEFAULT="none"NFQUEUE_DEFAULT="None"If you set the value of either option to "None" then no
default action will be used and the default action or macro must be
specified in shorewall6-policy(5).You can pass parameters to the
specified action or macro (e.g.,
myaction(audit,DROP)).Beginning with Shorewall 4.5.10, the action name can be
followed optionally by a colon and a log
level. The level will be applied to each
rule in the action or macro body that does not already have a log
level.ACCOUNTING=[Yes|No]Added in Shorewall 4.4.7. If set to Yes, Shorewall6 accounting
is enabled (see shorewall6-accounting(5)).
If not specified or set to the empty value, ACCOUNTING=Yes is
assumed.ACCOUNTING_TABLE=[filter|mangle]Added in Shorewall 4.4.20. This setting determines which
Netfilter table the accounting rules are added in. By default,
ACCOUNTING_TABLE=filter is assumed. See also shorewall-accounting(5).ADMINISABSENTMINDED=[Yes|No]The value of this variable affects Shorewall6's stopped state.
When ADMINISABSENTMINDED=No, only traffic to/from those addresses
listed in shorewall6-routestopped(5)
is accepted when Shorewall6 is stopped. When
ADMINISABSENTMINDED=Yes, in addition to traffic to/from addresses in
shorewall6-routestopped(5),
connections that were active when Shorewall6 stopped continue to
work and all new connections from the firewall system itself are
allowed. If this variable is not set or is given the empty value
then ADMINISABSENTMINDED=No is assumed.IGNOREUNKNOWNVARIABLES=[Yes|No]Added in Shorewall 4.5.11. Normally, if an unknown shell
variable is encountered in a configuration file (except in ?IF and
?ELSIF directives), the compiler raises a fatal error. If
IGNOREUNKNOWNVARIABLES is set to Yes, then such variables simply expand to an
empty string. Default is No.AUTOCOMMENT=[Yes|No]Formerly named AUTO_COMMENT. If set, if there is not a current
comment when a macro is invoked, the behavior is as if the first
line of the macro file was "COMMENT <macro name>". The
AUTO_COMMENT option has a default value of 'Yes'.AUTOHELPERS=[Yes|No]Added in Shorewall 4.5.7. When set to
(the default), the generated ruleset will automatically associate
helpers with applications that require them (FTP, IRC, etc.). When
configuring your firewall on systems running kernel 3.5 or later, it
is recommended that you:Set AUTOHELPERS=No.Either:Modify shorewall6-conntrack
(5) to only apply helpers where they are required; orSpecify the appropriate helper in the HELPER column in
shorewall6-rules
(5).The macros for those applications requiring a helper
automatically specify the appropriate HELPER where
required.AUTOMAKE=[Yes|No]If set, the behavior of the start and
restart commands is change; if no files in
/etc/shorewall have been
changed since the last successful start or
restart command, then the compilation step is
skipped and the compiled script that executed the last
start or restart command is
used. The default is AUTOMAKE=No.The setting of the AUTOMAKE option is ignored if the
start or restart command
includes a directory name (e.g., shorewall6 restart
/etc/shorewall.new).BLACKLIST_DISPOSITION=[DROP|A_DROP|REJECT|A_REJECT]This parameter determines the disposition of packets from
blacklisted hosts. It may have the value DROP if the packets are to
be dropped or REJECT if the packets are to be replied with an ICMP
port unreachable reply or a TCP RST (tcp only). If you do not assign
a value or if you assign an empty value then DROP is assumed. The
BLACKLIST_DISPOSITION setting has no effect on entries in the
BLACKLIST section of shorewall6-rules (5). It
determines the disposition of packets sent to the blacklog target of shorewall6-blrules(5).BLACKLIST_LOGLEVEL=[log-level]This parameter determines if packets from blacklisted hosts
are logged and it determines the syslog level that they are to be
logged at. Its value is a syslog level (Example:
BLACKLIST_LOGLEVEL=debug). If you do not assign a value or if you
assign an empty value then packets from blacklisted hosts are not
logged. The BLACKLIST_LOGLEVEL setting has no effect on entries in
the BLACKLIST section of shorewall6-rules (5). It
determines the log level of packets sent to the blacklog target of shorewall6-blrules(5).BLACKLISTNEWONLY={Yes|No}When set to Yes or yes, blacklists are only consulted for new
connections. This includes entries in the shorewall-blrules (5) file and in the BLACKLIST
section of shorewall6-rules (5).When set to No or no, blacklists are consulted for every packet
(will slow down your firewall noticably if you have large
blacklists). If the BLACKLISTNEWONLY option is not set or is set to
the empty value then BLACKLISTNEWONLY=No is assumed.BLACKLISTNEWONLY=No is incompatible with
FASTACCEPT=Yes.CLAMPMSS=[Yes|No|value]This parameter enables the TCP Clamp MSS to PMTU feature of
Netfilter and is usually required when your internet connection is
through PPPoE or PPTP. If set to Yes or yes,
the feature is enabled. If left blank or set to No or no,
the feature is not enabled.Important: This option
requires CONFIG_IP_NF_TARGET_TCPMSS in your kernel.You may also set CLAMPMSS to a numeric
value (e.g., CLAMPMSS=1400). This will set the
MSS field in TCP SYN packets going through the firewall to the
value that you specify.CLEAR_TC=[Yes|No]If this option is set to No
then Shorewall6 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/shorewall6/tcstart file. That way, your traffic shaping rules
can still use the “fwmark” classifier based on packet marking
defined in shorewall6-tcrules(5). If not
specified, CLEAR_TC=No is assumed.If you also run Shorewall and if you have
TC_ENABLED=Internal in your shorewall-conf(5),
then you will want CLEAR_TC=No in this file.COMPLETE=[Yes|No]Added in Shorewall6 4.4.12. When you set this option to Yes,
you are asserting that the configuration is complete so that your
set of zones encompasses any hosts that can send or receive traffic
to/from/through the firewall. This causes Shorewall6 to omit the
rules that catch packets in which the source or destination IP
address is outside of any of your zones. Default is No. It is
recommended that this option only be set to Yes if:You have defined an interface whose effective physical
setting is '+'.That interface is assigned to a zone.You have no CONTINUE policies or rules.CONFIG_PATH=[directory[:directory]...]Specifies where configuration files other than shorewall6.conf
may be found. CONFIG_PATH is specifies as a list of directory names
separated by colons (":"). When looking for a configuration file
other than shorewall6.conf:If the command is "try" or a "<configuration
directory>" was specified in the command (e.g.,
shorewall6 check ./gateway) then the
directory given in the command is searched first.Next, each directory in the CONFIG_PATH setting is
searched in sequence.If CONFIG_PATH is not given or if it is set to the empty value
then the contents of /usr/share/shorewall6/configpath are used. As
released from shorewall.net, that file sets the CONFIG_PATH to
/etc/shorewall6:/usr/share/shorewall6:/usr/share/shorewall but your
particular distribution may set it differently. See the output of
shorewall6 show config for the default on your system.DEFER_DNS_RESOLUTION=[Yes|No]Added in Shorewall 4.5.12. When set to 'Yes' (the default),
DNS names are validated in the compiler and then passed on to the
generated script where they are resolved by ip6tables-restore. This
is an advantage if you use AUTOMAKE=Yes and the IP address
associated with the DNS name is subject to change. When
DEFER_DNS_RESOLUTION=No, DNS names are converted into IP addresses
by the compiler. This has two advantages:When AUTOMAKE=Yes the start and
restart commands will succeed even if no DNS
server is reachable (assuming that the configuration hasn't
changed since the compiled script was last generated).The restore command (including the
automatic restore performed when
start or restart fails)
will succeed even if no DNS server is reachable.DELETE_THEN_ADD={Yes|No}If set to Yes (the default value), entries in the
/etc/shorewall6/route_stopped files cause an 'ip rule del' command
to be generated in addition to an 'ip rule add' command. Setting
this option to No, causes the 'ip rule del' command to be
omitted.DONT_LOAD=[module[,module]...]Causes Shorewall6 to not load the listed kernel
modules.DYNAMIC_BLACKLIST={Yes|No}Added in Shorewall 4.4.7. When set to No or no,
dynamic blacklisting using the shorewall6 drop,
shorewall6 reject, shorewall6
logdrop and shorewall6 logreject is
disabled. Default is Yes.EXPAND_POLICIES={Yes|No}Normally, when the SOURCE or DEST columns in
shorewall-policy(5) contains 'all', a single policy chain is created
and the policy is enforced in that chain. For example, if the policy
entry is#SOURCE DEST POLICY LOG
# LEVEL
net all DROP infothen the chain name is 'net2all'
which is also the chain named in Shorewall log messages generated as
a result of the policy. If EXPAND_POLICIES=Yes, then Shorewall will
create a separate chain for each pair of zones covered by the
policy. This makes the resulting log messages easier to interpret
since the chain in the messages will have a name of the form 'a2b'
where 'a' is the SOURCE zone and 'b' is the DEST zone.EXPORTMODULES=[Yes|No]Added in Shorewall 4.4.17. When set to Yes when compiling for
use by Shorewall6 Lite (shorewall6 load,
shorewall6 reload or shorewall6
export commands), the compiler will copy the modules or
helpers file from the administrative system into the script. When
set to No or not specified, the compiler will not copy the modules
or helpers file from /usr/share/shorewall6 but
will copy the found in another location on the CONFIG_PATH.When compiling for direct use by Shorewall6, causes the
contents of the local module or helpers file to be copied into the
compiled script. When set to No or not set, the compiled script
reads the file itself.EXPORTPARAMS={Yes|No}Deprecated beginning with Shorewall 4.4.17.Beginning with Shorewall 4.4.17, the variables set in the
'params' file at compile time are available at run time with
EXPORTPARAMS=No. As a consequence, beginning with that version the
recommended setting is EXPORTPARAMS=No.It is quite difficult to code a 'params' file that assigns
other than constant values such that it works correctly with
Shorewall6 Lite. The EXPORTPARAMS option works around this problem.
When EXPORTPARAMS=No, the 'params' file is not copied to the
compiler output.With EXPORTPARAMS=No, if you need to set environmental
variables on the firewall system for use by your extension scripts,
then do so in the init extension script.The default is EXPORTPARAMS=Yes which is the recommended
setting unless you are running Shorewall6 Lite.FASTACCEPT={Yes|No}Normally, Shorewall6 defers accepting ESTABLISHED/RELATED
packets until these packets reach the chain in which the original
connection was accepted. So for packets going from the 'loc' zone to
the 'net' zone, ESTABLISHED/RELATED packets are ACCEPTED in the
'loc2net' chain.If you set FASTACCEPT=Yes, then ESTABLISHED/RELEATED packets
are accepted early in the INPUT, FORWARD and OUTPUT chains. If you
set FASTACCEPT=Yes then you may not include rules in the ESTABLISHED
or RELATED sections of shorewall6-rules(5).FASTACCEPT=Yes is incompatible with
BLACKLISTNEWONLY=No.FORWARD_CLEAR_MARK={Yes|No}Added in Shorewall 4.4.11 Beta 3. Traditionally, Shorewall has
cleared the packet mark in the first rule in the mangle FORWARD
chain. This behavior is maintained with the default setting of this
option (FORWARD_CLEAR_MARK=Yes). If FORWARD_CLEAR_MARK is set to
'No', packet marks set in the mangle PREROUTING chain are retained
in the FORWARD chains.GEOIPDIR=[pathname]Added in Shorewall 4.5.4. Specifies the pathname of the
directory containing the GeoIP Match
database. See http://www.shorewall.net/ISO-3661.html.
If not specified, the default value is
/usr/share/xt_geoip/LE which is the default
location of the little-endian database.HELPERS=[helper[,helper...]]Added in Shorewall 4.5.7. This option lists the Netfilter
application helps that are to be enabled. If not specified, the
default is to enable all helpers.Possible values for helper
are:amandaftph323ircnetbios-nspptpsanesipsnmptftpWhen HELPERS is specified on a system running Kernel 3.5.0 or
later, automatic association of helpers to connections is
disabled.HIGH_ROUTE_MARKS={Yes|No}Deprecated in Shorewall 4.4.26 in favor of
PROVIDER_OFFSET.You may set HIGH_ROUTE_MARKS=Yes in to effectively divide the
packet mark and connection mark into two mark fields.The width of the fields are determined by the setting of the
WIDE_TC_MARKS option.When WIDE_TC_MARKS=No (the default):The MARK field in the providers file must have a value
that is less than 65536 and that is a multiple of 256 (using hex
representation, the values are 0x0100-0xFF00 with the low-order
8 bits being zero).You may only set those mark values in the PREROUTING
chain.Marks used for traffic shaping must still be in the range
of 1-255 and may still not be set in the PREROUTING
chain.When WIDE_TC_MARKS=Yes:The MARK field in the providers file must have a value
that is a multiple of 65536 (using hex representation, the
values are 0x010000-0xFF0000 with the low-order 16 bits being
zero).You may only set those mark values in the PREROUTING
chain.Marks used for traffic shaping must be in the range of
1-16383 and may still not be set in the PREROUTING chain.Regardless of the setting of WIDE_TC_MARKS, when you SAVE or
RESTORE in tcrules, only the TC mark value is saved or restored.
Shorewall handles saving and restoring the routing (provider)
marks.IMPLICIT_CONTINUE={Yes|No}When this option is set to Yes, it causes subzones to be treated
differently with respect to policies.Subzones are defined by following their name with ":" and a
list of parent zones (in shorewall6-zones(5)). Normally,
you want to have a set of special rules for the subzone and if a
connection doesn't match any of those subzone-specific rules then
you want the parent zone rules and policies to be applied; see
shorewall6-nesting(5).
With IMPLICIT_CONTINUE=Yes, that happens automatically.If IMPLICIT_CONTINUE=No or if IMPLICIT_CONTINUE is not set,
then subzones are not subject to this special treatment. With
IMPLICIT_CONTINUE=Yes, an implicit CONTINUE policy may be overridden
by including an explicit policy (one that does not specify "all" in
either the SOURCE or the DEST columns).IP=[pathname]If specified, gives the pathname of the 'ip' executable. If
not specified, 'ip' is assumed and the utility will be located using
the current PATH setting.IP_FORWARDING=[On|Off|Keep]This rather useless parameter determines whether Shorewall6
enables or disables IPV6 Packet Forwarding on all interfaces
(/proc/sys/net/ipv6/config/all/forwarding). Possible values
are:On or onpacket forwarding will be enabled.Off or offpacket forwarding will be disabled.Keep or keepShorewall6 will neither enable nor disable packet
forwarding
If this variable is not set or is given an empty value
(IP_FORWARD="") then IP_FORWARD=On is assumed.
IP6TABLES=[pathname]This parameter names the ip6tables executable to be used by
Shorewall6. If not specified or if specified as a null value, then
the ip6tables executable located using the PATH option is
used.Regardless of how the ip6tables utility is located (specified
via IP6TABLES= or located via PATH), Shorewall6 uses the
ip6tables-restore and ip6tables-save utilities from that same
directory.IPSET=[pathname]If specified, gives the pathname of the 'ipset' executable. If
not specified, 'ipset' is assumed and the utility will be located
using the current PATH setting.IPSET_WARNINGS={Yes|No}Added in Shorewall 4.5.2. Default is Yes. When set, causes the
rules compiler to issue a warning when:The compiler is being run by root and an ipset specified
in the configuration does not exists. Only one warning is issued
for each missing ipset.When [src] is specified in a destination column and when
[dst] is specified in a source column.KEEP_RT_TABLES={Yes|No}When set to , this option prevents scripts
generated by Shorewall6 from altering the /etc/iproute2/rt_tables
database when there are entries in
/etc/shorewall6/providers. If you set this
option to while Shorewall6 (Shorewall6-lite) is
running, you should remove the file
/var/lib/shorewall6/rt_tables
(/var/lib/shorewall6-lite/rt_tables) before
your next stop, refresh,
restore on restart
command.The default is KEEP_RT_TABLES=No.LEGACY_FASTSTART={Yes|No}Added in Shorewall6 4.4.20. If not specified, the default is
Yes which preserves the legacy behavior of start
-f (the modification times of the files in
/etc/shorewall6 are compare with that of
/var/lib/shorewall6/restore). If set to No,
then the times are compared with that of
/var/lib/shorewall6/firewall, which is consistant with the way that
restart -f works.LOAD_HELPERS_ONLY={Yes|No}Added in Shorewall 4.4.7. When set to Yes, restricts the set
of modules loaded by shorewall to those listed in
/var/lib/shorewall6/helpers and those that are actually used. When
not set, or set to the empty value, LOAD_HELPERS_ONLY=No is
assumed.LOCKFILE=[pathname]Specifies the name of the Shorewall6 lock file, used to
prevent simultaneous state-changing commands. If not specified,
${VARDIR}/shorewall6/lock is assumed (${VARDIR} is normally /var/lib
but can be changed when Shorewall-core is installed -- see the
output of shorewall6 show vardir).LOG_VERBOSITY=[number]This option controls the amount of information logged to the
file specified in the STARTUP_LOG option.Values are:-1 - Logging is disabled0 - Silent. Only error messages are logged.1 - Major progress messages logged.2 - All progress messages loggedIf not specified, then -1 is assumed.LOGALLNEW=[log-level]This option is intended for use as a debugging aid. When set
to a log level, this option causes Shorewall6 to generate a logging
rule as the first rule in each builtin chain.The table name is used as the chain name in the log
prefix.The chain name is used as the target in the log
prefix.
For example, using the default LOGFORMAT, the log prefix for
logging from the nat table's PREROUTING chain is: Shorewall:nat:PREROUTING
To help insure that all packets in the NEW state are
logged, rate limiting (LOGBURST and LOGRATE) should be disabled
when using LOGALLNEW. Use LOGALLNEW at your own risk; it may
cause high CPU and disk utilization and you may not be able to
control your firewall after you enable this option.Do not use this option if the resulting log messages will
be sent to another system.
LOGFILE=[pathname]This parameter tells the /sbin/shorewall6 program where to
look for Shorewall6 messages when processing the dump, logwatch, show
log, and hits commands.
If not assigned or if assigned an empty value, /var/log/messages is
assumed.LOGFORMAT=["formattemplate"]The value of this variable generate the --log-prefix setting
for Shorewall6 logging rules. It contains a “printf” formatting
template which accepts three arguments (the chain name, logging rule
number (optional) and the disposition). To use LOGFORMAT with
fireparse, set it as: LOGFORMAT="fp=%s:%d a=%s "If the LOGFORMAT value contains the substring “%d” then the
logging rule number is calculated and formatted in that position; if
that substring is not included then the rule number is not included.
If not supplied or supplied as empty (LOGFORMAT="") then
“Shorewall6:%s:%s:” is assumed.The setting of LOGFORMAT has an effect of the permitted
length of zone names. See shorewall6-zones (5).LOGLIMIT=[[{s|d}:]rate/{sec|min|hour|day}[:burst]]Added in Shorewall 4.4.12. Limits the logging rate, either
overall, or by source or destination IP address.If the value starts with 's:' then logging is limited per
source IP. If the value starts with 'd:', then logging is limited
per destination IP. Otherwise, the overall logging rate is
limited.If burst is not specified, then a
value of 5 is assumed.LOGBURST=[burst]Deprecated in Shorewall 4.4.12.LOGRATE=[rate/{minute|second}]As of Shorewall 4.4.12, these parameters are
Deprecated.These parameters set the match rate and initial burst size for
logged packets. Please see ip6tables(8) for a description of the
behavior of these parameters (the ip6tables option --limit is set by
LOGRATE and --limit-burst is set by LOGBURST). If both parameters
are set empty, no rate-limiting will occur. If you supply one of
these, then you should also supply the other.Example: LOGRATE=10/minute
LOGBURST=5For each logging rule, the first time the rule is reached, the
packet will be logged; in fact, since the burst is 5, the first five
packets will be logged. After this, it will be 6 seconds (1 minute
divided by the rate of 10) before a message will be logged from the
rule, regardless of how many packets reach it. Also, every 6
seconds, one of the bursts will be regained; if no packets hit the
rule for 30 seconds, the burst will be fully recharged; back where
we started.LOGTAGONLY=[Yes|No]Using the default LOGFORMAT, chain names may not exceed 11
characters or truncation of the log prefix may occur. Longer chain
names may be used with log tags if you set LOGTAGONLY=Yes. With
LOGTAGONLY=Yes, if a log tag is specified then the tag is included
in the log prefix in place of the chain name.Beginning with Shorewall 4.5.12, when LOGTAGONLY=Yes, you have
more control over the generated log prefix. Beginning with that
release, the tag is interpreted as a chain
name and a disposition
separated by a comma. So this rule:#ACTION SOURCE DEST
LOG:info:foo,bar net fwwould generate the following log prefix when using the default
LOGFORMAT setting:Shorewall:foo:bar:Similarly,#ACTION SOURCE DEST
LOG:info:,bar net fwwould generateShorewall:net2fw:bar:MACLIST_DISPOSITION=[ACCEPT|DROP|REJECT|A_DROP|A_REJECT]Determines the disposition of connections requests that fail
MAC Verification and must have the value ACCEPT (accept the
connection request anyway), REJECT (reject the connection request)
or DROP (ignore the connection request). If not set or if set to the
empty value (e.g., MACLIST_DISPOSITION="") then
MACLIST_DISPOSITION=REJECT is assumed.A_DROP and A_REJECT are audited versions of DROP and REJECT
respectively and were added in Shorewall 4.4.20. They require
AUDIT_TARGET in the kernel and ip6tables.MACLIST_LOG_LEVEL=[log-level]Determines the syslog level for logging connection requests
that fail MAC Verification. The value must be a valid syslogd log
level. If you don't want to log these connection requests, set to
the empty value (e.g., MACLIST_LOG_LEVEL="").MACLIST_TABLE=[filter|mangle]Normally, MAC verification occurs in the filter table (INPUT
and FORWARD) chains. When forwarding a packet from an interface with
MAC verification to a bridge interface, that doesn't work.This problem can be worked around by setting
MACLIST_TABLE=mangle which will cause Mac verification to occur out
of the PREROUTING chain. Because REJECT isn't available in that
environment, you may not specify MACLIST_DISPOSITION=REJECT with
MACLIST_TABLE=mangle.MACLIST_TTL=[number]The performance of configurations with a large numbers of
entries in shorewall-maclist(5) can be
improved by setting the MACLIST_TTL variable in shorewall.conf(5).If your iptables and kernel support the "Recent Match" (see
the output of "shorewall check" near the top), you can cache the
results of a 'maclist' file lookup and thus reduce the overhead
associated with MAC Verification.When a new connection arrives from a 'maclist' interface, the
packet passes through then list of entries for that interface in
shorewall-maclist(5). If
there is a match then the source IP address is added to the 'Recent'
set for that interface. Subsequent connection attempts from that IP
address occurring within $MACLIST_TTL seconds will be accepted
without having to scan all of the entries. After $MACLIST_TTL from
the first accepted connection request from an IP address, the next
connection request from that IP address will be checked against the
entire list.If MACLIST_TTL is not specified or is specified as empty (e.g,
MACLIST_TTL="" or is specified as zero then 'maclist' lookups will
not be cached).MANGLE_ENABLED=[Yes|No]Determines whether Shorewall will generate rules in the
Netfilter mangle table. Setting MANGLE_ENABLED=No disables all
Shorewall features that require the mangle table. The default is
MANGLE_ENABLED=Yes.MARK_IN_FORWARD_CHAIN=[Yes|No]If your kernel has a FORWARD chain in the mangle table, you
may set MARK_IN_FORWARD_CHAIN=Yes to cause the marking specified in
the tcrules file to occur in that chain rather than in the
PREROUTING chain. This permits you to mark inbound traffic based on
its destination address when DNAT is in use. To determine if your
kernel has a FORWARD chain in the mangle table, use the /sbin/shorewall6 show mangle command; if a
FORWARD chain is displayed then your kernel will support this
option. If this option is not specified or if it is given the empty
value (e.g., MARK_IN_FORWARD_CHAIN="") then MARK_IN_FORWARD_CHAIN=No
is assumed.MASK_BITS=[number]Added in Shorewall 4.4.26. Number of bits on the right of the
32-bit packet mark to be masked when clearing the traffic shaping
mark. Must be >= TC_BITS and <= PROVIDER_OFFSET (if
PROVIDER_OFFSET > 0). Default value and the default values of the
other mark layout options is determined as follows:
MODULE_SUFFIX=["extension ..."]The value of this option determines the possible file
extensions of kernel modules. The default value is "ko ko.gz o o.gz
gz".MODULESDIR=[pathname[:pathname]...]This parameter specifies the directory/directories where your
kernel netfilter modules may be found. If you leave the variable
empty, Shorewall6 will supply "/lib/modules/`uname
-r`/kernel/net/ipv4/netfilter:/lib/modules/`uname
-r`/kernel/net/ipv4/netfilter".MUTEX_TIMEOUT=[seconds]The value of this variable determines the number of seconds
that programs will wait for exclusive access to the Shorewall6 lock
file. After the number of seconds corresponding to the value of this
variable, programs will assume that the last program to hold the
lock died without releasing the lock.If not set or set to the empty value, a value of 60 (60
seconds) is assumed.An appropriate value for this parameter would be twice the
length of time that it takes your firewall system to process a
shorewall6 restart command.NFACCT=[pathname]Added in Shorewall 4.5.7. Specifies the pathname of the nfacct
utiliity. If not specified, Shorewall will use the PATH settting to
find the program.OPTIMIZE=[value]The specified value enables certain
optimizations. Each optimization category is associated with a power
of two. To enable multiple optimization categories, simply add their
corresponding numbers together.Optimization category 1 - Traditionally, Shorewall has
created rules for the complete matrix of
host groups defined by the zones, interfaces and hosts
files. Any traffic that didn't correspond to an element
of that matrix was rejected in one of the built-in chains. When
the matrix is sparse, this results in lots of largely useless
rules.These extra rules can be eliminated by setting the 1 bit
in OPTIMIZE.The 1 bit setting also controls the suppression of
redundant wildcard rules (those specifying "all" in the SOURCE
or DEST column). A wildcard rule is considered to be redundant
when it has the same ACTION and Log Level as the applicable
policy.Optimization category 2 - Added in Shorewall 4.4.7. When
set, suppresses superfluous ACCEPT rules in a policy chain that
implements an ACCEPT policy. Any ACCEPT rules that immediately
preceed the final blanket ACCEPT rule in the chain are now
omitted.Optimization category 4 - Added in Shorewall 4.4.7. When
set, causes short chains (those with less than 2 rules) to be
optimized away. The following chains are excluded from
optimization:accounting chains (unless
OPTIMIZE_ACCOUNTING=Yes)action chains (user-defined)'blacklst' chaindynamicAdditionally:If a built-in chain has a single rule that branches to
a second chain, then the rules from the second chain are
moved to the built-in chain and the target chain is
omitted.Chains with no references are deleted.Accounting chains are subject to optimization if the
OPTIMIZE_ACCOUNTING option is set to 'Yes'.If a chain ends with an unconditional branch to a
second chain (other than to 'reject'), then the branch is
deleted from the first chain and the rules from the second
chain are appended to it.An additional optimization was added in Shorewall 4.5.4.
If the last rule in a chain is an unqualified jump to a simple
target, then all immediately preceding rules with the same
simple target are omitted.For example, consider this chain: -A fw-net -p udp --dport 67:68 -j ACCEPT
-A fw-net -p udp --sport 1194 -j ACCEPT
-A fw-net -p 41 -j ACCEPT
-A fw-net -j ACCEPT
Since all of the rules are jumps to the simple target
ACCEPT, this chain is totally optimized away and jumps to the
chain are replace with jumps to ACCEPT.Optimization category 8 - Added in Shorewall 4.4.9. When
set, causes chains with identical rules to be collapsed into a
single chain.Optimization category 16 - Added in Shorewall 4.4.26. When
set, causes sequences of compatible rules
to be combined into a single rule. Rules are considered
compatible if they differ only in their destination ports and
comments.A sequence of combatible rules is often generated when
macros are invoked in sequence.The ability to combine adjacent rules is limited by two
factors:Destination port lists may only be combined up to a
maximum of 15 ports, where a port-pair counts as two
ports.Rules may only be combined until the length of their
concatinated comment reaches 255 characters.When either of these limits would be exceeded, the current
combined rule is emitted and the compiler attemts to combine
rules beginning with the one that would have exceeded the limit.
Adjacent combined comments are separated by ', '. Empty comments
at the front of a group of combined comments are replaced by
'Others and'. Empty comments at the end of a group of combined
comments are replaced by 'and others'.Beginning in Shorewall 4.5.10, this option also suppresses
duplicate adjacent rules and duplicate non-adjacent rules that
don't include mark, connmark, dscp, ecn, set, tos
or u32 matches.Example 1:Rules with comments "FOO", <empty> and "BAR"
would result in the combined comment "FOO and others,
BAR".Example 2:Rules with comments <empty>, "FOO" and "BAR"
would reult in the combined comment "Others and FOO, BAR".
Note: Optimize level 16 requires "Extended Multi-port
Match" in your iptables and kernel.The default value is zero which disables all
optimizations.OPTIMIZE_ACCOUNTING=[Yes|No]Added in Shorewall 4.4.7. If set to Yes, Shorewall accounting
changes are subject to optimization (OPTIMIZE=4,5,6 or 7). If not
specified or set to the empty value, OPTIMIZE_ACCOUNTING=No is
assumed.PATH=pathname[:pathname]...Determines the order in which Shorewall6 searches directories
for executable files.PERL=pathnameAdded in Shorewall 4.4.11 RC1. Specifies the path name of the
Perl executable. Default is /usr/bin/perl. If
the pathname specified by this option does not exist or the named
file is not executable, then Shorewall6 falls back to
/usr/bin/perl/PROVIDER_BITS=[number]Added in Shorewall 4.4.26. The number of bits in the 32-bit
packet mark to be used for provider numbers. May be zero. See MASK_BITS above for default value.PROVIDER_OFFSET=[number]Added in Shorewall 4.4.26. The offset from the right
(low-order end) of the provider number field in the 32-bit packet
mark. If non-zero, must be >= TC_BITS (Shorewall automatically
adjusts PROVIDER_OFFSET's value). PROVIDER_OFFSET + PROVIDER_BITS +
ZONE_BITS must be < 32. See MASK_BITS above for default value.RCP_COMMAND="command"RSH_COMMAND="command"Eariler generations of Shorewall6 Lite required that remote
root login via ssh be enabled in order to use the
load and reload commands.
Beginning with release 3.9.5, you may define an alternative means
for accessing the remote firewall system. In that release, two new
options were added to shorewall6.conf:RSH_COMMANDRCP_COMMANDThe default values for these are as
follows:RSH_COMMAND: ssh ${root}@${system} ${command}RCP_COMMAND: scp ${files}
${root}@${system}:${destination}Shell variables that will be set when the commands
are envoked are as follows:root - root user. Normally
but may be overridden using the '-r'
option.system - The name/IP address
of the remote firewall system.command - For RSH_COMMAND,
the command to be executed on the firewall system.files - For RCP_COMMAND, a
space-separated list of files to be copied to the remote
firewall system.destination - The directory
on the remote system that the files are to be copied
into.RELATED_DISPOSITION=[ACCEPT|A_ACCEPT|A_DROP|A_REJECT|DROP|REJECT]Added in Shorewall 4.4.27. Shorewall has traditionally
ACCEPTed RELATED packets that don't match any rule in the RELATED
section of shorewall6-rules (5).
Concern about the safety of this practice resulted in the addition
of this option. When a packet in RELATED state fails to match any
rule in the RELATED section, the packet is disposed of based on this
setting. The default value is ACCEPT for compatibility with earlier
versions.RELATED_LOG_LEVEL=log-levelAdded in Shorewall 4.4.27. Packets in the related state that
do not match any rule in the RELATED section of shorewall6-rules (5) are
logged at this level. The default value is empty which means no
logging is performed.REQUIRE_INTERFACE=[Yes|No]Added in Shorewall 4.4.10. The default is No. If set to Yes,
at least one optional interface must be up in order for the firewall
to be in the started state. Intended to be used with the Shorewall Init
Package.RESTORE_ROUTEMARKS=[Yes|No]Added in Shorewall 4.5.9. When set to Yes (the default), provider marks are
restored unconditionally at the top of the mangle OUTPUT and
PREROUTING chains, even if the saved mark is zero. When this option
is set to No, the mark is restored
even when it is zero. If you have problems with IPSEC ESP packets
not being routed correctly on output, try setting this option to
No.RESTOREFILE=filenameSpecifies the simple name of a file in /var/lib/shorewall6 to
be used as the default restore script in the shorewall6 save, shorewall6 restore, shorewall6 forget and shorewall6 -f start commands.RPFILTER_DISPOSITION=[DROP|REJECT|A_DROP|A_REJECT]Added in Shorewall 4.5.7. Determines the disposition of
packets entering from interfaces with the
option (see shorewall-interfaces(5)).
Packets disposed of by this option are those whose response packets
would not be sent through the same interface receiving the
packet.RPFILTER_LOG_LEVEL=log-levelAdded in shorewall 4.5.7. Determines the logging of packets
disposed via the RPFILTER_DISPOSITION. The default value is
.SHOREWALL_SHELL=[pathname]This option is used to specify the shell program to be used to
interpret the compiled script. If not specified or specified as a
null value, /bin/sh is assumed. Using a light-weight shell such as
ash or dash can significantly improve performance.SMURF_DISPOSITION=[DROP|A_DROP]Added in Shorewall 4.4.20. The default setting is DROP which
causes smurf packets (see the nosmurfs option in shorewall-interfaces(5)) to
be dropped. A_DROP causes the packets to be audited prior to being
dropped and requires AUDIT_TARGET support in the kernel and
ip6tables.SMURF_LOG_LEVEL=[log-level]Specifies the logging level for smurf packets (see the
nosmurfs option in shorewall6-interfaces(5)).
If set to the empty value ( SMURF_LOG_LEVEL="" ) then smurfs are not
logged.SFILTER_DISPOSITION=[DROP|REJECT|A_DROP|A_REJECT]Added in Shorewall 4.4.20. Determines the disposition of
packets matching the option (see shorewall6-interfaces(5))
and of hairpin packets on interfaces without
the option.Hairpin packets are packets that are routed out of the
same interface that they arrived on. interfaces without the routeback option.SFILTER_LOG_LEVEL=log-levelAdded on Shorewall 4.4.20. Determines the logging of packets
matching the option (see shorewall6-interfaces(5))
and of hairpin packets on interfaces without
the option.Hairpin packets are packets that are routed out of the
same interface that they arrived on. interfaces without the routeback option. The default
is . If you don't wish for these packets to be
logged, use SFILTER_LOG_LEVEL=none.STARTUP_ENABLED={Yes|No}Determines if Shorewall6 is allowed to start. As released from
shorewall.net, this option is set to No. When set to Yes or yes,
Shorewall6 may be started. Used as a guard against Shorewall6 being
accidentally started before it has been configured.STARTUP_LOG=[pathname]If specified, determines where Shorewall6 will log the details
of each start, restart and refresh command. Logging verbosity is
determined by the setting of LOG_VERBOSITY above.SUBSYSLOCK=[pathname]This parameter should be set to the name of a file that the
firewall should create if it starts successfully and remove when it
stops. Creating and removing this file allows Shorewall6 to work
with your distribution's initscripts. For RedHat, this should be set
to /var/lock/subsys/shorewall6. For Debian, the value is
/var/lock/shorewall6 and in LEAF it is /var/run/shorwall.TC=[pathname]If specified, gives the pathname of the 'tc' executable. If
not specified, 'tc' is assumed and the utility will be located using
the current PATH setting.TC_BITS=[number]Added in Shorewall 4.4.26. The number of bits at the low end
of the 32-bit packet mark to be used for traffic shaping marking.
May be zero. See MASK_BITS above
for default value.TC_ENABLED=[Yes|No|Internal|Shared]If you say Yes or yes here, Shorewall6 will use a script that
you supply to configure traffic shaping. The script must be named
'tcstart' and must be placed in a directory on your
CONFIG_PATH.If you say No or no then traffic shaping is not
enabled.If you set TC_ENABLED=Internal or internal or leave the option
empty then Shorewall6 will use its builtin traffic shaper
(tc4shorewall6 written by Arne Bernin.Beginning with Shorewall 4.4.15, if you set TC_ENABLED=Shared
or shared, then you should create symbolic links from your
Shorewall6 configuration directory (normally
/etc/shorewall6/) to your Shorewall
tcdevices and tcclasses
files. This allows the compiler to have access to your Shorewall
traffic shaping configuration so that it can validate CLASSIFY rules
in shorewall6-tcrules
(5).If you also run Shorewall and if you have
TC_ENABLED=Internal in your shorewall-conf(5),
then you will want TC_ENABLED=No or TC_ENABLED=Shared in this
file.TC_EXPERT={Yes|No}Normally, Shorewall6 tries to protect users from themselves by
preventing PREROUTING and OUTPUT tcrules from being applied to
packets that have been marked by the 'track' option in shorewall6-providers(5).If you know what you are doing, you can set TC_EXPERT=Yes and
Shorewall6 will not include these cautionary checks.TC_PRIOMAP=mapAdded in Shorewall 4.4.6. Determines the mapping of a packet's
TOS field to priority bands. See shorewall6-tcpri(5). The
map consists of 16 space-separated digits with
values 1, 2 or 3. A value of 1 corresponds to Linux priority 0, 2 to
Linux priority 1, and 3 to Linux Priority 2. The first entry gives
the priority of TOS value 0, the second of TOS value 1, and so on.
See tc-prio(8) for additional information.The default setting is TC_PRIOMAP="2 3 3 3 2 3 1 1 2 2 2 2 2 2
2 2".TCP_FLAGS_DISPOSITION=[ACCEPT|DROP|REJECT]Determines the disposition of TCP packets that fail the checks
enabled by the tcpflags interface
option (see shorewall6-interfaces(5))
and must have a value of ACCEPT (accept the packet), REJECT (send an
RST response) or DROP (ignore the packet). If not set or if set to
the empty value (e.g., TCP_FLAGS_DISPOSITION="") then
TCP_FLAGS_DISPOSITION=DROP is assumed.TCP_FLAGS_LOG_LEVEL=[log-level]Determines the syslog level for logging packets that fail the
checks enabled by the tcpflags interface option. The value must be a
valid syslogd log level. If you don't want to log these packets, set
to the empty value (e.g., TCP_FLAGS_LOG_LEVEL="").TRACK_PROVIDERS={Yes|No}Added in Shorewall 4.4.3. When set to Yes, causes the
option to be assumed on all providers defined
in shorewall6-providers(5). May
be overridden on an individual provider through use of the
option. The default value is 'No'.Beginning in Shorewall 4.4.6, setting this option to 'Yes'
also simplifies PREROUTING rules in shorewall6-tcrules(5).
Previously, when TC_EXPERT=No, packets arriving through 'tracked'
provider interfaces were unconditionally passed to the PREROUTING
tcrules. This was done so that tcrules could reset the packet mark
to zero, thus allowing the packet to be routed using the 'main'
routing table. Using the main table allowed dynamic routes (such as
those added for VPNs) to be effective. The shorewall6-rtrules(5) file was
created to provide a better alternative to clearing the packet mark.
As a consequence, passing these packets to PREROUTING complicates
things without providing any real benefit. Beginning with Shorewall
4.4.6, when TRACK_PROVIDERS=Yes and TC_EXPERT=No, packets arriving
through 'tracked' interfaces will not be passed to the PREROUTING
rules. Since TRACK_PROVIDERS was just introduced in 4.4.3, this
change should be transparent to most, if not all, users.USE_DEFAULT_RT=[Yes|No]Added in Shorewall6 4.4.25. When set to 'Yes', this option
causes the Shorewall6 multi-ISP feature to create a different set of
routing rules which are resilient to changes in the main routing
table. Such changes can occur for a number of reasons, VPNs going up
and down being an example. The idea is to send packets through the
main table prior to applying any of the Shorewall6-generated routing
rules. So changes to the main table will affect the routing of
packets by default.When USE_DEFAULT_RT=Yes:Both the DUPLICATE and the COPY columns in shorewall6-providers(5)
file must remain empty (or contain "-").The default route is added to the the 'default' table
rather than to the main table.balance is assumed unless
loose is specified.Packets are sent through the main routing table by a rule
with priority 999. In shorewall6-routing_rules(5),
the range 1-998 may be used for inserting rules that bypass the
main table.All provider gateways must be specified explicitly in the
GATEWAY column. detect may not
be specified.You should disable all default route management outside of
Shorewall6. If a default route is added to the main table while
Shorewall is started, then all policy routing will stop working
(except for those routing rules in the priority range
1-998).If USE_DEFAULT_RT is not set or if it is set to the empty
string then USE_DEFAULT_RT=No is assumed.USE_PHYSICAL_NAMES=[Yes|No]Added in Shorewall 4.4.27. Normally, when Shorewall creates a
Netfilter chain that relates to an interface, it uses the
interfaces's logical name as the base of the chain name. For
example, if the logical name for an interface is OAKLAND, then the
input chain for traffic arriving on that interface would be
'OAKLAND_in'. If this option is set to Yes, then the physical name
of the interface will be used the base of the chain name.VERBOSITY=[number]Shorewall6 has traditionally been very noisy (produced lots of
output). You may set the default level of verbosity using the
VERBOSITY OPTION.Values are:0 - Silent. You may make it more verbose using the -v
option1 - Major progress messages displayed2 - All progress messages displayed (pre Shorewall6-3.2.0
behavior)If not specified, then 2 is assumed.WARNOLDCAPVERSION=[Yes|No]Added in Shorewall 4.5.12. When set to Yes (the default), the compiler issues a
warning when it finds a capabilities file that doesn't specify all
of the capabilities supported by the compiler. When
WARNOLDCAPVERSION is set to No, no
warning is issued.WIDE_TC_MARKS={Yes|No}Deprecated in Shorewall 4.4.26 in favor of TC_BITS and
MASK_BITS.When set to No (the default), traffic shaping marks are 8
bytes wide (possible values are 1-255). When WIDE_TC_MARKS=Yes,
traffic shaping marks are 14 bytes wide (values 1-16383). The
setting of WIDE_TC_MARKS also has an effect on the HIGH_ROUTE_MARKS
option (see above).ZONE_BITS=[number]Added in Shorewall 4.4.26. When non-zero, enables automatic
packet marking by source zone and determines the number of bits in
the 32-bit packet mark to be used for the zone mark. Default value
is 0.ZONE2ZONE={|}Added in Shorewall 4.4.4. This option determines how Shorewall
constructs chain names involving zone names and/or 'all'. The
default is '2' (e.g., fw2net).FILES/etc/shorewall6/shorewall6.confSee ALSOshorewall6(8), shorewall6-accounting(5), shorewall6-actions(5),
shorewall6-blacklist(5), shorewall6-hosts(5), shorewall6-interfaces(5),
shorewall6-ipsec(5), shorewall6-maclist(5), shorewall6-masq(5),
shorewall6-nat(5), shorewall6-netmap(5),
shoewall6-netmap(5),shorewall6-params(5), shorewall6-policy(5),
shorewall6-providers(5), shorewall6-proxyarp(5), shorewall6-rtrules(5),
shorewall6-routestopped(5), shorewall6-rules(5), shorewall6-tcclasses(5),
shorewall6-tcdevices(5), shorewall6-tcrules(5), shorewall6-tos(5),
shorewall6-tunnels(5), shorewall6-zones(5)