Provided by: shorewall_4.5.21.6-1_all 
NAME
shorewall.conf - Shorewall global configuration file
SYNOPSIS
/etc/shorewall/shorewall.conf
DESCRIPTION
This file sets options that apply to Shorewall as a whole.
The file consists of Shell comments (lines beginning with '#'), blank lines and assignment
statements (variable=value). If the value contains shell meta characters or white-space,
then it must be enclosed in quotes. Example: MACLIST_LOG_LEVEL="NFLOG(1,0,1)".
OPTIONS
Many 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 Shorewall also uses that term.
Valid levels are:
7 debug
6 info
5 notice
4 warning
3 err
2 crit
1 alert
0 emerg
For most Shorewall logging, a level of 6 (info) is appropriate. Shorewall log messages are
generated by NetFilter and are logged using facility 'kern' and the level that you
specify. 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 ULOG and/or NFLOG target support, you may also specify
a log level of ULOG and/or NFLOG (must be all caps). Rather than log its messages to
syslogd, Shorewall will direct netfilter to log the messages via the ULOG or 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
Shorewall messages to their own log file.
Note
If you want to specify parameters to ULOG or NFLOG (e.g., NFLOG(1,0,1)), then you must
either quote the setting or you must escape the parentheses.
Examples:
MACLIST_LOG_LEVEL="NFLOG(1,0,1)"
or
MACLIST_LOG_LEVEL=NFLOG\(1,0,1\)
Beginning with Shorewall 4.4.22, LOGMARK is also a valid level which logs the packet's
mark value along with the other usual information. The syntax is:
LOGMARK[(priority)]
where priority is one of the levels listed in the list above. If omitted, the default is
info (6).
The following options may be set in shorewall.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}
In earlier Shorewall versions, a "default action" for DROP and REJECT policies was
specified in the file /usr/share/shorewall/actions.std.
In Shorewall 4.4.0, the DROP_DEFAULT, REJECT_DEFAULT, ACCEPT_DEFAULT, QUEUE_DEFAULT
and NFQUEUE_DEFAULT options were added.
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:
The 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 shorewall-policy[1](5).
You can pass parameters to the specified action (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 body that
does not already have a log level.
ACCOUNTING=[Yes|No]
Added in Shorewall 4.4.7. If set to Yes, Shorewall accounting is enabled (see
shorewall-accounting[2](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[2](5).
ADD_IP_ALIASES=[Yes|No]
This parameter determines whether Shorewall automatically adds the external
address(es) in shorewall-nat[3](5). If the variable is set to Yes or yes then
Shorewall automatically adds these aliases. If it is set to No or no, you must add
these aliases yourself using your distribution's network configuration tools.
If this variable is not set or is given an empty value (ADD_IP_ALIASES="") then
ADD_IP_ALIASES=Yes is assumed.
Warning
Addresses added by ADD_IP_ALIASES=Yes are deleted and re-added during shorewall
restart. As a consequence, connections using those addresses may be severed.
ADD_SNAT_ALIASES=[Yes|No]
This parameter determines whether Shorewall automatically adds the SNAT ADDRESS in
shorewall-masq[4](5). If the variable is set to Yes or yes then Shorewall
automatically adds these addresses. If it is set to No or no, you must add these
addresses yourself using your distribution's network configuration tools.
If this variable is not set or is given an empty value (ADD_SNAT_ALIASES="") then
ADD_SNAT_ALIASES=No is assumed.
Warning
Addresses added by ADD_SNAT_ALIASES=Yes are deleted and re-added during shorewall
restart. As a consequence, connections using those addresses may be severed.
ADMINISABSENTMINDED=[Yes|No]
The value of this variable affects Shorewall's stopped state. When
ADMINISABSENTMINDED=No, only traffic to/from those addresses listed in
shorewall-routestopped[5](5) is accepted when Shorewall is stopped. When
ADMINISABSENTMINDED=Yes, in addition to traffic to/from addresses in
shorewall-routestopped[5](5), connections that were active when Shorewall 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.
ARPTABLES=[pathname]
Added in Shorewall 4.5.12. This parameter names the arptables executable to be used by
Shorewall. If not specified or if specified as a null value, then the arptables
executable located using the PATH option is used.
Regardless of how the arptables utility is located (specified via arptables= or
located via PATH), Shorewall uses the arptables-restore and arptables-save utilities
from that same directory.
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'.
The setting of the AUTOMAKE option is ignored if the start or restart command includes
a directory name (e.g., shorewall restart /etc/shorewall.new).
AUTOHELPERS=[Yes|No]
Added in Shorewall 4.5.7. When set to Yes (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:
1. Set AUTOHELPERS=No.
2. Either:
1. Modify shorewall-conntrack[6] (5) to only apply helpers where they are
required; or
2. Specify the appropriate helper in the HELPER column in shorewall-rules[7] (5).
Note
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' command is changed; 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.
BLACKLIST=[{ALL|state[,...]}]
where state is one of NEW, ESTABLISHED, RELATED, INVALID,or UNTRACKED.
Added in Shorewall 4.5.13 to replace the BLACKLISTNEWONLY option below. Specifies the
connection tracking states that are to be subject to blacklist screening. If neither
BLACKLIST nor BLACKLISTNEWONLY are specified then the states subject to blacklisting
are NEW,ESTABLISHED,INVALID,UNTRACKED.
ALL sends all packets through the blacklist chains.
Note: The ESTABLISHED state may not be specified if FASTACCEPT is specified.
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.
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 iptables.
The BLACKLIST_DISPOSITION setting has no effect on entries in the BLACKLIST section of
shorewall-rules[7] (5). It determines the disposition of packets sent to the blacklog
target of shorewall-blrules[8](5).
BLACKLIST_LOG_LEVEL=[log-level]
Formerly named BLACKLIST_LOGLEVEL. 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_LOG_LEVEL=debug). If you do
not assign a value or if you assign an empty value then packets from blacklisted hosts
are not logged. The setting determines the log level of packets sent to the blacklog
target of shorewall-blrules[8](5).
BLACKLISTNEWONLY={Yes|No}
Deprecated in Shorewall 4.5.13 in favor of BLACKLIST above.
When set to Yes or yes, blacklists are only consulted for new connections and for
packets in the INVALID connection state (such as TCP SYN,ACK when there has been no
corresponding SYN). That includes entries in the shorewall-blrules[9] (5) file and in
the BLACKLIST section of shorewall-rules[7] (5).
When set to No or no, blacklists are consulted for every packet (will slow down your
firewall noticeably if you have large blacklists). If the BLACKLISTNEWONLY option is
not set or is set to the empty value then BLACKLISTNEWONLY=No is assumed.
Note
BLACKLISTNEWONLY=No is incompatible with FASTACCEPT=Yes.
CHAIN_SCRIPTS={Yes|No}
Added in Shorewall 4.5.16. Prior to the availability of BEGIN PERL....END PERL in
configuration files, the only way to execute a chain-specific script was to create a
script file with the same name as the chain and place it in a directory on the
CONFIG_PATH. That facility has the drawback that the compiler will attempt to run a
non-script file just because it has the same name as a chain. To disable this
facility, set CHAIN_SCRIPTS=No. If not specified or specified as the empty value,
CHAIN_SCRIPTS=Yes is assumed.
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 Shorewall won't clear the current traffic control
rules during [re]start. This setting is intended for use by people who prefer to
configure traffic shaping when the network interfaces come up rather than when the
firewall is started. If that is what you want to do, set TC_ENABLED=Yes and
CLEAR_TC=No and do not supply an /etc/shorewall/tcstart file. That way, your traffic
shaping rules can still use the “fwmark” classifier based on packet marking defined in
shorewall-tcrules[10](5). If not specified, CLEAR_TC=Yes is assumed.
COMPLETE=[Yes|No]
Added in Shorewall 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 Shorewall 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 shorewall.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 shorewall.conf:
• If the command is "try" or a "<configuration directory>" was specified in the
command (e.g., shorewall 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/shorewall/configpath are used. As released from shorewall.net, that file
sets the CONFIG_PATH to /etc/shorewall:/usr/share/shorewall but your particular
distribution may set it differently. See the output of shorewall 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
iptables-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 the advantage that
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).
DELETE_THEN_ADD={Yes|No}
If set to Yes (the default value), entries in the /etc/shorewall/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.
DETECT_DNAT_IPADDRS=[Yes|No]
If set to Yes or yes, Shorewall will detect the first IP address of the interface to
the source zone and will include this address in DNAT rules as the original
destination IP address. If set to No or no, Shorewall will not detect this address and
any destination IP address will match the DNAT rule. If not specified or empty,
“DETECT_DNAT_IPADDRS=Yes” is assumed.
DISABLE_IPV6=[Yes|No]
If set to Yes or yes, IPv6 traffic to, from and through the firewall system is
disabled. If set to No or no, Shorewall will take no action with respect to allowing
or disallowing IPv6 traffic. If not specified or empty, “DISABLE_IPV6=No” is assumed.
It is important to note that changing DISABLE_IPV6=Yes to DISABLE_IPV6=No does not
enable IPV6. The recommended approach for enabling IPv6 on your system is:
• Install, configure and start Shorewall6[11].
• Change DISABLE_IPV6=Yes to DISABLE_IPV6=No
• Restart Shorewall
DONT_LOAD=[module[,module]...]
Causes Shorewall 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
shorewall drop, shorewall reject, shorewall logdrop and shorewall 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 info
then 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 Shorewall Lite
(shorewall load, shorewall reload or shorewall 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/shorewall but will copy the found in another location on the
CONFIG_PATH.
When compiling for direct use by Shorewall, 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 in 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 Shorewall 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 using
Shorewall Lite.
FASTACCEPT={Yes|No}
Normally, Shorewall 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/RELATED 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 shorewall-rules[7](5).
Note
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:
• amanda
• ftp
• h323
• irc
• netbios-ns
• none - This special value was added in Shorewall 4.5.16 and indicates that no
helpers are to be enabled. It also prevents the compiler for probing for helper
support; such probing generates messages on the system log of the form "xt_CT: No
such helper XXX" where XXX is the helper name. When used, none must be the only
helper specified.
• pptp
• sane
• sip
• snmp
• tftp
When 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.
Prior to version 3.2.0, it was not possible to use connection marking in
shorewall-tcrules[10](5) if you had a multi-ISP configuration that uses the track
option.
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 WIDE_TC_MARKS. If
WIDE_TC_MARKS=No (the default):
1. 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).
2. You may only set those mark values in the PREROUTING chain.
3. 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:
1. 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).
2. You may only set those mark values in the PREROUTING chain.
3. 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.
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.
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
shorewall-zones[12](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 shorewall-nesting[13](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).
INVALID_DISPOSITION=[A_DROP|A_REJECT|DROP|REJECT|CONTINUE]
Added in Shorewall 4.5.13. Shorewall has traditionally passed INVALID packets through
the NEW section of shorewall-rules[7] (5). When a packet in INVALID state fails to
match any rule in the INVALID section, the packet is disposed of based on this
setting. The default value is CONTINUE for compatibility with earlier versions.
INVALID_LOG_LEVEL=log-level
Added in Shorewall 4.5.13. Packets in the INVALID state that do not match any rule in
the INVALID section of shorewall-rules[14] (5) are logged at this level. The default
value is empty which means no logging is performed.
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 parameter determines whether Shorewall enables or disables IPV4 Packet Forwarding
(/proc/sys/net/ipv4/ip_forward). Possible values are:
On or on
packet forwarding will be enabled.
Off or off
packet forwarding will be disabled.
Keep or keep
Shorewall 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.
IPSECFILE=zones
This option indicates that zone-related ipsec information is found in the zones file
(shorewall-zones[12](5)). The option indicates to the compiler that this is not a
legacy configuration where the ipsec information was contained in a separate file. The
value of this option must not be changed and the option must not be deleted.
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.
IPTABLES=[pathname]
This parameter names the iptables executable to be used by Shorewall. If not specified
or if specified as a null value, then the iptables executable located using the PATH
option is used.
Regardless of how the iptables utility is located (specified via IPTABLES= or located
via PATH), Shorewall uses the iptables-restore and iptables-save utilities from that
same directory.
KEEP_RT_TABLES={Yes|No}
When set to Yes, this option prevents generated scripts from altering the
/etc/iproute2/rt_tables database when there are entries in /etc/shorewall/providers.
If you set this option to Yes while Shorewall (Shorewall-lite) is running, you should
remove the file /var/lib/shorewall/rt_tables (/var/lib/shorewall-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 Shorewall 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/shorewall are
compare with that of /var/lib/shorewall/restore). If set to No, then the times are
compared with that of /var/lib/shorewall/firewall, which is consistent 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/shorewall/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 Shorewall lock file, used to prevent simultaneous
state-changing commands. If not specified, ${VARDIR}/shorewall/lock is assumed
(${VARDIR} is normally /var/lib but can be changed when Shorewall-core is installed --
see the output of shorewall show vardir).
LOG_MARTIANS=[Yes|No|Keep]
If set to Yes or yes, sets /proc/sys/net/ipv4/conf/*/log_martians to 1 with the
exception of /proc/sys/net/ipv4/conf/all/log_martians which is set to 0. The default
value is Yes which sets both of the above to one. If you do not enable martian logging
for all interfaces, you may still enable it for individual interfaces using the
logmartians interface option in shorewall-interfaces[15](5).
The value Keep causes Shorewall to ignore the option. If the option is set to Yes,
then martians are logged on all interfaces. If the option is set to No, then martian
logging is disabled on all interfaces except those specified in
shorewall-interfaces[15](5).
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 disabled
0 - Silent. Only error messages are logged.
1 - Major progress messages logged.
2 - All progress messages logged
If 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 Shorewall 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
Important
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.
Caution
Do not use this option if the resulting log messages will be sent to another
system.
LOGFILE=[pathname]
This parameter tells the /sbin/shorewall program where to look for Shorewall 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. For further information, see
http://www.shorewall.net/shorewall_logging.html.
LOGFORMAT=["formattemplate"]
The value of this variable generate the --log-prefix setting for Shorewall 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
“Shorewall:%s:%s:” is assumed.
Note
The setting of LOGFORMAT has an effect of the permitted length of zone names. See
shorewall-zones[12] (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}]
Deprecated in Shorewall 4.4.12. These options are ignored when LOGLIMIT is specified.
These parameters set the match rate and initial burst size for logged packets. Please
see iptables(8) for a description of the behavior of these parameters (the iptables
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=5
For 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 fw
would generate the following log prefix when using the default LOGFORMAT setting:
Shorewall:foo:bar:
Similarly,
#ACTION SOURCE DEST
LOG:info:,bar net fw
would generate
Shorewall: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 iptables.
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 or
MACLIST_DISPOSITION=A_REJECT with MACLIST_TABLE=mangle.
MACLIST_TTL=[number]
The performance of configurations with a large numbers of entries in
shorewall-maclist[16](5) can be improved by setting the MACLIST_TTL variable in
shorewall.conf[17](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[16](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.
MAPOLDACTIONS=[Yes|No]
This option is included for compatibility with old Shorewall configuration. New
installs should always have MAPOLDACTIONS=No.
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/shorewall 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:
Table 1. Default Packet Mark Layout
WIDE_TC_MARKS=No, TC_BITS=8, PROVIDER_BITS=8,
HIGH_ROUTE_MARKS=No PROVIDER_OFFSET=0,
MASK_BITS=8
WIDE_TC_MARKS=No, TC_BITS=8, PROVIDER_BITS=8,
HIGH_ROUTE_MARKS=Yes PROVIDER_OFFSET=8,
MASK_BITS=8
WIDE_TC_MARKS=Yes, TC_BITS=14, PROVIDER_BITS=8,
HIGH_ROUTE_MARKS=No PROVIDER_OFFSET=0,
MASK_BITS=16
WIDE_TC_MARKS=Yes, TC_BITS=14, PROVIDER_BITS=8,
HIGH_ROUTE_MARKS=Yes PROVIDER_OFFSET=16,
MASK_BITS=16
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, Shorewall will supply the value
"/lib/modules/`uname -r`/kernel/net/ipv4/netfilter" in versions of Shorewall prior to
3.2.4 and "/lib/modules/`uname -r`/kernel/net/ipv4/netfilter:/lib/modules/`uname
-r`/kernel/net/ipv4/netfilter" in later versions.
MULTICAST=[Yes|No]
This option will normally be set to 'No' (the default). It should be set to 'Yes'
under the following circumstances:
1. You have an interface that has parallel zones defined via /etc/shorewall/hosts.
2. You want to forward multicast packets to two or more of those parallel zones.
In such cases, you will configure a destonly network on each zone receiving
multicasts.
MUTEX_TIMEOUT=[seconds]
The value of this variable determines the number of seconds that programs will wait
for exclusive access to the Shorewall 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 shorewall restart command.
NFACCT=[pathname]
Added in Shorewall 4.5.7. Specifies the pathname of the nfacct utility. If not
specified, Shorewall will use the PATH setting to find the program.
NULL_ROUTE_RFC1918=[Yes|No|blackhole|unreachable|prohibit]
When set to Yes, causes Shorewall to null-route the IPv4 address ranges reserved by
RFC1918. The default value is 'No'.
When combined with route filtering (ROUTE_FILTER=Yes or routefilter in
shorewall-interfaces[15](5)), this option ensures that packets with an RFC1918 source
address are only accepted from interfaces having known routes to networks using such
addresses.
Beginning with Shorewall 4.5.15, you may specify blackhole, unreachable or prohibit to
set the type of route to be created. See
http://www.shorewall.net/MultiISP.html#null_routing.
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.
Beginning with Shorewall 4.5.20, you may specify OPTIMIZE=All to enable all
optimization categories, and you may also specify OPTIMIZE=None to disable
optimization.
• Optimization category 1 - Traditionally, Shorewall has created rules for the
complete matrix of host groups defined by the zones, interfaces and hosts
files[18]. 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.
Note
Optimization level 1 is ignored when optimization level 4 is also selected,
since level 4 performs similar optimizations in a more robust way.
• 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 precede 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' chain
• dynamic
• forwardUPnP
• UPnP (nat table)
Additionally:
• 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 compatible 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 concatenated comment
reaches 255 characters.
When either of these limits would be exceeded, the current combined rule is
emitted and the compiler attempts 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 result 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 Shorewall searches directories for executable files.
PERL=pathname
Added 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 Shorewall 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]If
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"
Earlier generations of Shorewall 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 shorewall.conf:.RS 4 RSH_COMMAND
RCP_COMMAND
The default values for these are as follows:.RS 4 RSH_COMMAND: ssh ${root}@${system}
${command}
RCP_COMMAND: scp ${files}
${root}@${system}:${destination}
Shell variables that will be set when the commands are invoked are as follows:.RS 4 root -
root user. Normally
root 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|CONTINUE]
Added in Shorewall 4.4.27. Shorewall has traditionally ACCEPTed RELATED packets that
don't match any rule in the RELATED section of shorewall-rules[7] (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-level
Added in Shorewall 4.4.27. Packets in the related state that do not match any rule in
the RELATED section of shorewall-rules[7] (5) are logged at this level. The default
value is empty which means no logging is performed.
REJECT_ACTION=action
Added in Shorewall 4.5.21. When a REJECT target is specified, Shorewall normally
handles the response as follows:
• If the destination address of the packet is a broadcast or multicast address, the
packet is dropped.
• if the protocol is ICMP (2) then the packet is dropped.
• if the protocol is TCP (6) then the packet is rejected with an RST.
• if the protocol is UDP (17) then the packet is rejected with an 'port-unreachable'
ICMP (ICMP6).
• if the protocol is ICMP (1) then the packet is rejected with a 'host-unreachable'
ICMP.
• otherwise, the packet is rejected with a 'host-prohibited' ICMP.
You can modify this behavior by implementing your own action that handles REJECT and
specifying it's name in this option. The nolog and inline options will automatically
be assumed for the specified action.
The following action implements the standard behavior:
?format 2
#TARGET SOURCE DEST PROTO
Broadcast(DROP) - - -
DROP - - 2
INLINE - - 6 ; -j REJECT --reject-with tcp-reset
?if __ENHANCED_REJECT
INLINE - - 17 ; -j REJECT
?if __IPV4
INLINE - - 1 ; -j REJECT --reject-with icmp-host-unreachable
INLINE - - - ; -j REJECT --reject-with icmp-host-prohibited
?else
INLINE - - 58 ; -j REJECT --reject-with icmp6-addr-unreachable
INLINE - - - ; -j REJECT --reject-with icmp6-adm-prohibited
?endif
?else
INLINE - - - ; -j REJECT
?endif
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[19].
RESTORE_DEFAULT_ROUTE=[Yes|No]
This option determines whether to restore the default route saved when here are
'balance' providers defined but all of them are down.
The default is RESTORE_DEFAULT_ROUTE=Yes which preserves the pre-4.2.6 behavior.
RESTORE_DEFAULT_ROUTE=No is appropriate when you don't want a default route in the
main table (USE_DEFAULT_RT=No) or in the default table (USE_DEFAULT_RT=Yes) when there
are no balance providers available. In that case, RESTORE_DEFAULT_ROUTE=No will cause
any default route in the relevant table to be deleted.
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=filename
Specifies the simple name of a file in /var/lib/shorewall to be used as the default
restore script in the shorewall save, shorewall restore, shorewall forget and
shorewall -f start commands.
RETAIN_ALIASES={Yes|No}
During shorewall start, IP addresses to be added as a consequence of
ADD_IP_ALIASES=Yes and ADD_SNAT_ALIASES=Yes are quietly deleted when
shorewall-nat[3](5) and shorewall-masq[4](5) are processed then are re-added later.
This is done to help ensure that the addresses can be added with the specified labels
but can have the undesirable side effect of causing routes to be quietly deleted. When
RETAIN_ALIASES is set to Yes, existing addresses will not be deleted. Regardless of
the setting of RETAIN_ALIASES, addresses added during shorewall start are still
deleted at a subsequent shorewall stop or shorewall restart.
ROUTE_FILTER=[Yes|No|Keep]
If this parameter is given the value Yes or yes then route filtering (anti-spoofing)
is enabled on all network interfaces which are brought up while Shorewall is in the
started state. The default value is no.
The value Keep causes Shorewall to ignore the option. If the option is set to Yes,
then route filtering occurs on all interfaces. If the option is set to No, then route
filtering is disabled on all interfaces except those specified in
shorewall-interfaces[15](5).
Important
If you need to disable route filtering on any interface, then you must set
ROUTE_FILTER=No then set routefilter=1 or routefilter=2 on those interfaces where
you want route filtering. See shorewall-interfaces[15](5) for additional details.
RPFILTER_DISPOSITION=[DROP|REJECT|A_DROP|A_REJECT]
Added in Shorewall 4.5.7. Determines the disposition of packets entering from
interfaces the rpfilter option (see shorewall-interfaces[15](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-level
Added in shorewall 4.5.7. Determines the logging of packets disposed via the
RPFILTER_DISPOSITION. The default value is info.
SAVE_ARPTABLES={Yes|No}
Added in Shorewall 4.5.12. If SAVE_ARPTABLES=Yes, then the current arptables contents
will be saved by shorewall save command and restored by shorewall restore command.
Default value is No.
SAVE_IPSETS={Yes|No}
Re-enabled in Shorewall 4.4.6. If SAVE_IPSETS=Yes, then the current contents of your
ipsets will be saved by the shorewall stop and shorewall save commands and restored by
the shorewall start and shorewall restore commands.
SFILTER_DISPOSITION=[DROP|REJECT|A_DROP|A_REJECT]
Added in Shorewall 4.4.20. Determines the disposition of packets matching the sfilter
option (see shorewall-interfaces[15](5)) and of hairpin packets on interfaces without
the routeback option.[20] interfaces without the routeback option.
SFILTER_LOG_LEVEL=log-level
Added on Shorewall 4.4.20. Determines the logging of packets matching the sfilter
option (see shorewall-interfaces[15](5)) and of hairpin packets on interfaces without
the routeback option.[21] interfaces without the routeback option. The default is
info. If you don't wish for these packets to be logged, use SFILTER_LOG_LEVEL=none.
SHOREWALL_SHELL=[pathname]
This option is used to specify the shell program to be used to run the Shorewall
compiler and 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[15](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 iptables.
SMURF_LOG_LEVEL=[log-level]
Specifies the logging level for smurf packets (see the nosmurfs option in
shorewall-interfaces[15](5)). If set to the empty value ( SMURF_LOG_LEVEL="" ) then
smurfs are not logged.
STARTUP_ENABLED={Yes|No}
Determines if Shorewall is allowed to start. As released from shorewall.net, this
option is set to No. When set to Yes or yes, Shorewall may be started. Used as a guard
against Shorewall being accidentally started before it has been configured.
STARTUP_LOG=[pathname]
If specified, determines where Shorewall 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 Shorewall to work with your distribution's initscripts. For RedHat and
OpenSuSE, this should be set to /var/lock/subsys/shorewall. For Debian, the value is
/var/lock/shorewall and in LEAF it is /var/run/shorewall.
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]
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|Simple|Shared]
If you say Yes or yes here, Shorewall 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=Simple (Shorewall 4.4.6 and later), simple traffic shaping using
shorewall-tcinterfaces[22](5) and shorewall-tcpri[23](5) is enabled.
If you set TC_ENABLED=Internal or internal or leave the option empty then Shorewall
will use its builtin traffic shaper (tc4shorewall written by Arne Bernin.
Beginning with Shorewall 4.4.15, you can set TC_ENABLED=Shared. This allows you to
configure the tcdevices and tcclasses in your Shorewall6 configuration yet make them
available to the compiler when compiling your Shorewall configuration. In addition to
setting TC_ENABLED=Shared, you need to create symbolic links from your Shorewall
configuration directory (normally /etc/shorewall/) to the tcdevices and tcclasses
files in your Shorewall6 configuration directory (normally /etc/shorewall6/).
TC_EXPERT={Yes|No}
Normally, Shorewall 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 shorewall-providers[24](5).
If you know what you are doing, you can set TC_EXPERT=Yes and Shorewall will not
include these cautionary checks.
TC_PRIOMAP=map
Added in Shorewall 4.4.6. Determines the mapping of a packet's TOS field to priority
bands. See shorewall-tcpri[23](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|A_DROP|A_REJECT]
Determines the disposition of TCP packets that fail the checks enabled by the tcpflags
interface option (see shorewall-interfaces[15](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.
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 iptables.
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 track option to be assumed on
all providers defined in shorewall-providers[24](5). May be overridden on an
individual provider through use of the notrack option. The default value is 'No'.
Beginning in Shorewall 4.4.6, setting this option to 'Yes' also simplifies PREROUTING
rules in shorewall-tcrules[10](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 rtrules
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.
TRACK_RULES={Yes|No}
Added in Shorewall 4.5.20. If set to Yes, causes the compiler to add a comment to
iptables rules to indicate the file name and line number of the configuration entry
that generated the rule. If set to No (the default), then no such comments are added.
Setting this option to Yes requires the Comments capability in iptables and kernel.
UNTRACKED_DISPOSITION=[ACCEPT|A_ACCEPT|A_DROP|A_REJECT|DROP|REJECT|CONTINUE]
Added in Shorewall 4.5.13. Shorewall has traditionally passed UNTRACKED packets
through the NEW section of shorewall-rules[7] (5). When a packet in UNTRACKED state
fails to match any rule in the UNTRACKED section, the packet is disposed of based on
this setting. The default value is CONTINUE for compatibility with earlier versions.
UNTRACKED_LOG_LEVEL=log-level
Added in Shorewall 4.5.13. Packets in the UNTRACKED state that do not match any rule
in the UNTRACKED section of shorewall-rules[7] (5) are logged at this level. The
default value is empty which means no logging is performed.
USE_DEFAULT_RT=[Yes|No]
When set to 'Yes', this option causes the Shorewall 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 Shorewall-generated routing rules. So changes to the main table will affect the
routing of packets by default.
When USE_DEFAULT_RT=Yes:
1. Both the DUPLICATE and the COPY columns in providers[24](5) file must remain empty
(or contain "-").
2. The default route is added to the the 'default' table rather than to the main
table.
3. balance is assumed unless loose is specified.
4. Packets are sent through the main routing table by a rule with priority 999. In
routing_rules[25](5), the range 1-998 may be used for inserting rules that bypass
the main table.
5. All provider gateways must be specified explicitly in the GATEWAY column. detect
may not be specified..if n .sp
Note
detect may be specified for interfaces whose configuration is managed by
dhcpcd. Shorewall will use dhcpcd's database to find the interface's gateway.
6. You should disable all default route management outside of Shorewall. 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 interface'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.
USE_RT_NAMES=[Yes|No]
Added in Shorewall 4.5.15. When set to 'Yes', Shorewall will use routing table
(provider) names in the generated script rather than table numbers. When set to 'No'
(the default), routing table numbers will be used.
Caution
If you set USE_RT_NAMES=Yes and KEEP_RT_TABLES=Yes, then you must insure that all
of your providers have entries in /etc/iproute2/rt_tables as well as the following
entries:
255 local
254 main
253 default
250 balance
0 unspec
Without these entries, the firewall will fail to start.
VERBOSITY=[number]
Shorewall 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
option
1 - Major progress messages displayed
2 - All progress messages displayed (pre Shorewall-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={2|-}
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/shorewall/shorewall.conf
SEE ALSO
shorewall(8), shorewall-accounting(5), shorewall-actions(5), shorewall-blacklist(5),
shorewall-hosts(5), shorewall_interfaces(5), shorewall-ipsets(5), shorewall-maclist(5),
shorewall-masq(5), shorewall-nat(5), shorewall-netmap(5), shorewall-params(5),
shorewall-policy(5), shorewall-providers(5), shorewall-proxyarp(5), shorewall-rtrules(5),
shorewall-routestopped(5), shorewall-rules(5), shorewall-tcclasses(5),
shorewall-tcdevices(5), shorewall-tcinterfaces(5), shorewall-tcpri(5),
shorewall-tcrules(5), shorewall-tos(5), shorewall-tunnels(5), shorewall-zones(5)
NOTES
1. shorewall-policy
http://www.shorewall.netshorewall-policy.html
2. shorewall-accounting
http://www.shorewall.netshorewall-accounting.html
3. shorewall-nat
http://www.shorewall.netshorewall-nat.html
4. shorewall-masq
http://www.shorewall.netshorewall-masq.html
5. shorewall-routestopped
http://www.shorewall.netshorewall-routestopped.html
6. shorewall-conntrack
http://www.shorewall.netshorewall-conntrack.html
7. shorewall-rules
http://www.shorewall.netshorewall-rules.html
8. shorewall-blrules
http://www.shorewall.netshorewall-blrules.html
9. shorewall-blrules
http://www.shorewall.net???
10. shorewall-tcrules
http://www.shorewall.netshorewall-tcrules.html
11. Shorewall6
http://www.shorewall.net../IPv6Support.html
12. shorewall-zones
http://www.shorewall.netshorewall-zones.html
13. shorewall-nesting
http://www.shorewall.netshorewall-nesting.html
14. shorewall-rules
http://www.shorewall.netmanpages/shorewall-rules.html
15. shorewall-interfaces
http://www.shorewall.netshorewall-interfaces.html
16. shorewall-maclist
http://www.shorewall.netshorewall-maclist.html
17. shorewall.conf
http://www.shorewall.netshorewall.conf.html
18. the complete matrix of host groups defined by the zones, interfaces and hosts files
http://www.shorewall.net../ScalabilityAndPerformance.html
19. Shorewall Init Package
http://www.shorewall.netshorewall-init.html
20. Hairpin packets are packets that are routed out of the same interface that they
arrived on.
21. Hairpin packets are packets that are routed out of the same interface that they
arrived on.
22. shorewall-tcinterfaces
http://www.shorewall.netshorewall-tcinterfaces.html
23. shorewall-tcpri
http://www.shorewall.netshorewall-tcpri.html
24. shorewall-providers
http://www.shorewall.netshorewall-providers.html
25. routing_rules
http://www.shorewall.netshorewall-routing_rules.html
[FIXME: source] 01/30/2014 SHOREWALL.CONF(5)