Provided by: shorewall6_5.0.4-1_all 
NAME
shorewall6.conf - Shorewall6 global configuration file
SYNOPSIS
/etc/shorewall6/shorewall6.conf
DESCRIPTION
This 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 meta characters or white-space, then it must be enclosed in
quotes. Example: 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 Shorewall6 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 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 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 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 file
Note
If you want to specify parameters to ULOG or NFLOG (e.g., NFLOG(1,0,1)), then you must quote the
setting.
Example:
MACLIST_LOG_LEVEL="NFLOG(1,0,1)"
Beginning with Shorewall 5.0.0, the log level may be followed by a colon (":") and a log tag. The log tag
normally follows the packet disposition in Shorewall-generated Netfilter log messages, separated from the
disposition by a colon (e.g, "DROP:mytag"). See LOGTAGONLY below for additional information.
The 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 none
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 shorewall6-policy[1](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[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 shorewall6-accounting[2](5).
ADMINISABSENTMINDED=[Yes|No]
The value of this variable affects Shorewall's stopped state. The behavior differs depending on
whether shorewall-routestopped[3](5) or shorewall-stoppedrules[4](5) is used:
routestopped
When ADMINISABSENTMINDED=No, only traffic to/from those addresses listed in routestopped is
accepted when Shorewall is stopped. When ADMINISABSENTMINDED=Yes, in addition to traffic to/from
addresses in routestopped, connections that were active when Shorewall stopped continue to work
and all new connections from the firewall system itself are allowed.
stoppedrules
All existing connections continue to work. To sever all existing connections when the firewall is
stopped, install the conntrack utility and place the command conntrack -F in the stopped user
exit (/etc/shorewall6/stopped).
If ADMINISABSENTMINDED=No, only new connections matching entries in stoppedrules are accepted
when Shorewall is stopped. Response packets and related connections are automatically accepted.
If ADMINISABSENTMINDED=Yes, in addition to connections matching entries in stoppedrules, all new
connections from the firewall system itself are allowed when the firewall is stopped. Response
packets and related connections are automatically accepted.
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 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. Modify the HELPERS setting (see below) to list the helpers that you need.
3. Either:
1. Modify shorewall6-conntrack[5] (5) to only apply helpers where they are required; or
2. Specify the appropriate helper in the HELPER column in shorewall6-rules[6] (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, reload and restart commands is changed; if no files in the
CONFIG_PATH (see below) have been changed since the last successful start, reload or restart command,
then the compilation step is skipped and the compiled script that executed the last start, reload or
restart command is used. The default is AUTOMAKE=No.
The setting of the AUTOMAKE option is ignored if the start, reload or restart command includes a
directory name (e.g., shorewall6 restart /etc/shorewall.new).
BASIC_FILTERS=[Yes|No]
Added in Shorewall-4.6.0. When set to Yes, causes entries in shorewall6-tcfilters(5)[7] to generate a
basic filter rather than a u32 filter. This setting requires the Basic Ematch capability in your
kernel and iptables.
Note
One of the advantages of basic filters is that ipset matches are supported in newer iproute2 and
kernel versions. Because Shorewall6 cannot reliably detect this capability, use of basic filters
is controlled by this option.
The default value is No which causes u32 filters to be generated.
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. Specifies the connection tracking
states that are to be subject to blacklist screening. If BLACKLIST is not specified then the states
subject to blacklisting are NEW,ESTABLISHED,INVALID,UNTRACKED.
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. The setting determines the disposition of packets sent to the blacklog
target of shorewall6-blrules[8](5).
BLACKLIST_LOG_LEVEL=[log-level[:log-tag]]
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 shorewall6-blrules[8](5).
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 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[9](5). If not specified, CLEAR_TC=No is assumed.
Warning
If you also run Shorewall and if you have TC_ENABLED=Internal in your shorewall-conf[10](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:
• 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 the advantage that when AUTOMAKE=Yes the start, reload 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/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 info
then the chain name is 'net-all' ("net2all" if ZONE2ZONE=2) 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.
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/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 shorewall6-rules[6](5).
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[11]. 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 specifies a comma-separated list naming the Netfilter
application helpers 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.
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[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 shorewall6-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).
INLINE_MATCHES={Yes|No}
Added in Shorewall 4.6.0. Traditionally in shorewall6-rules(5)[6], a semicolon separates
column-oriented specifications on the left from alternative specificaitons[14] on the right.. When
INLINE_MATCHES=Yes is specified, the specifications on the right are interpreted as if INLINE had
been specified in the ACTION column. This also applies to shorewall6-masq(5)[15] and
shorewall6-mangle(5[16]) which also support INLINE. If not specified or if specified as the empty
value, the value 'No' is assumed for backward compatibility.
Beginning with Shorewall 5.0.0, it is no longer necessary to set INLINE_MATCHES=Yes in order to be
able to specify your own iptables text in a rule. You may simply preface that text with a pair of
semicolons (";;"). If alternate input is also specified in the rule, it should appear before the
semicolons and may be seperated from normal column input by a single semicolon.
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[6] (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[:log-tag]
Added in Shorewall 4.5.13. Packets in the INVALID state that do not match any rule in the INVALID
section of shorewall6-rules[6] (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 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 on
packet forwarding will be enabled.
Off or off
packet forwarding will be disabled.
Keep or keep
Shorewall6 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 Yes, 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 Yes 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, reload or restart command.
The default is KEEP_RT_TABLES=No.
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_BACKEND=[backend]
Added in Shorewall 4.6.4. LOG_BACKEND determines the logging backend to be used for the iptrace
command (see shorewall6(8)[17]).
backend is one of:
LOG
Use standard kernel logging.
netlink
Use netlink logging to ulogd version 2 or later.
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
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
Important
To help insure that all packets in the NEW state are logged, rate limiting (LOGLIMIT) 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/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.
Note
The setting of LOGFORMAT has an effect of the permitted length of zone names. See
shorewall6-zones[12] (5).
LOGLIMIT=[[{s|d}:]rate/{sec|second|min|minute|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.
The keywords second and minute are accepted beginning with Shorewall 4.6.13.
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 ip6tables.
MACLIST_LOG_LEVEL=[log-level[:log-tag]]
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 shorewall6-maclist[18](5) can be
improved by setting the MACLIST_TTL variable in shorewall6.conf[19](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 shorewall6-maclist[18](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 /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). Prior to Shorewall 5.0.0, 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, HIGH_ROUTE_MARKS=No TC_BITS=8, PROVIDER_BITS=8,
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
From 5.0.0 onward, the default value of MASK_BITS is 8, the default value of PROVIDER_BITS, TC_BITS,
MASK_BITS and PROVIDER_OFFSET is 8.
MODULE_SUFFIX=["extension ..."]
The value of this option determines the possible file extensions of kernel modules. The default value
is "ko ko.gz ko.xz o o.gz o.xz gz xz".
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/kernel/net/ipv${g_family}/netfilter:/lib/modules/$uname/kernel/net/netfilter:/lib/modules/$uname/kernel/net/sched:/lib/modules/$uname/extra:/lib/modules/$uname/extra/ipset"
where uname holds the output of 'uname -r' and g_family holds '6'.
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 utility. If not specified, Shorewall
will use the PATH setting 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.
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[20]. 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
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 Shorewall6 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 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"
Earlier 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:.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 shorewall6-rules[6] (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[:log-tag]
Added in Shorewall 4.4.27. Packets in the related state that do not match any rule in the RELATED
section of shorewall6-rules[6] (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 (58) 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 'addr-unreachable' ICMP.
• otherwise, the packet is rejected with a 'adm-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[21].
RESTART=[restart|reload]
Added in Shorewall 5.0.1 to replace LEGACY_RESTART which was added in Shorewall 5.0.0. In that
release, the reload command was redefined to do what restart had done in earlier releases and restart
became a true restart (equivalent to stop followed by start). When RESTART=reload, the restart
command performs the same operation as the reload command making it compatible with earlier releases.
If not specified, RESTART=reload is assumed.
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/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
rpfilter option (see shorewall6-interfaces[22](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[:log-tag]
Added in shorewall 4.5.7. Determines the logging of packets disposed via the RPFILTER_DISPOSITION.
The default value is info.
SAVE_IPSETS={Yes|No|setlist}
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.
Beginning with Shorewall 4.6.4, you can restrict the set of ipsets saved by specifying a setlist (a
comma-separated list of ipv6 ipset names).
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 shorewall6-interfaces[22](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[:log-tag]]
Specifies the logging level for smurf packets (see the nosmurfs option in
shorewall6-interfaces[22](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 sfilter option (see
shorewall6-interfaces[22](5)) and of hairpin packets on interfaces without the routeback option.[23]
interfaces without the routeback option.
SFILTER_LOG_LEVEL=log-level[:log-tag]
Added on Shorewall 4.4.20. Determines the logging of packets matching the sfilter option (see
shorewall6-interfaces[22](5)) and of hairpin packets on interfaces without the routeback option.[24]
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.
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, reload, 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/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]
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|Simple|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.
If you set TC_ENABLED=Simple (Shorewall 4.4.6 and later), simple traffic shaping using
shorewall-tcinterfaces[25](5) and shorewall-tcpri[26](5) is enabled.
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[9] (5).
Warning
If you also run Shorewall and if you have TC_ENABLED=Internal in your shorewall-conf[10](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[27](5).
If you know what you are doing, you can set TC_EXPERT=Yes and Shorewall6 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
shorewall6-tcpri[28](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[22](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[:log-tag]]
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 shorewall6-providers[27](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
shorewall6-tcrules[9](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[29](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.
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 ip6tables 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 shorewall6-rules[6] (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[:log-tag]
Added in Shorewall 4.5.13. Packets in the UNTRACKED state that do not match any rule in the UNTRACKED
section of shorewall6-rules[6] (5) are logged at this level. The default value is empty which means
no logging is performed.
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 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:
1. Both the DUPLICATE and the COPY columns in shorewall6-providers[27](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
shorewall6-routing_rules[30](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.
6. 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).
Prior to Shorewall 4.6.0, if USE_DEFAULT_RT was not set or if it was set to the empty string then
USE_DEFAULT_RT=No was assumed. Beginning with Shorewall 4.6.0, the default is USE_DEFAULT_RT=Yes and
use of USE_DEFAULT_RT=No is deprecated.
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]
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
option
1 - Major progress messages displayed
2 - 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).
WORKAROUNDS=[Yes|No]
Added in Shorewall 4.6.11. Over time, there have been a number of changes in Shorewall that work
around defects in other products such as iptables and ipset. When WORKAROUNDS=Yes, these workarounds
are enabled; when WORKAROUNDS=No, they are disabled. If not specified or if specified as empty,
WORKAROUNDS=Yes is assumed.
Warning
Do not set WORKAROUNDS=Yes if you need to be able to use Shorewall-generated scripts (such as
created by the save command) built by Shorewall 4.4.7 or older.
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'. Beginning with Shorewall 4.6.0, the default is '-' (e.g., fw-net); prior to that
release, the default was '2' (e.g., fw2net).
FILES
/etc/shorewall6/shorewall6.conf
SEE ALSO
shorewall6(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), shorewall6-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)
NOTES
1. shorewall6-policy
http://www.shorewall.net/manpages6/shorewall6-policy.html
2. shorewall6-accounting
http://www.shorewall.net/manpages6/shorewall6-accounting.html
3. shorewall-routestopped
http://www.shorewall.netshorewall-routestopped.html
4. shorewall-stoppedrules
http://www.shorewall.netshorewall-stoppedrules.html
5. shorewall6-conntrack
http://www.shorewall.net/manpages6/shorewall6-conntrack.html
6. shorewall6-rules
http://www.shorewall.net/manpages6/shorewall6-rules.html
7. shorewall6-tcfilters(5)
http://www.shorewall.netshorewall6-tcfilters.html
8. shorewall6-blrules
http://www.shorewall.net/manpages6/shorewall6-blrules.html
9. shorewall6-tcrules
http://www.shorewall.net/manpages6/shorewall6-tcrules.html
10. shorewall-conf
http://www.shorewall.net/manpages/shorewall.conf.html
11. http://www.shorewall.net/ISO-3661.html
http://www.shorewall.net/ISO-3661.html
12. shorewall6-zones
http://www.shorewall.net/manpages6/shorewall6-zones.html
13. shorewall6-nesting
http://www.shorewall.net/manpages6/shorewall6-nesting.html
14. alternative specificaitons
http://www.shorewall.net/configuration_file_basics.htm#Pairs
15. shorewall6-masq(5)
http://www.shorewall.netshorewall6-masq.html
16. shorewall6-mangle(5
http://www.shorewall.netshorewall6-mangle.html
17. shorewall6(8)
http://www.shorewall.netmanpages6/shorewall6.html
18. shorewall6-maclist
http://www.shorewall.net/manpages6/shorewall6-maclist.html
19. shorewall6.conf
http://www.shorewall.net/manpages6/shorewall6.conf.html
20. the complete matrix of host groups defined by the zones, interfaces and hosts files
http://www.shorewall.net/ScalabilityAndPerformance.html
21. Shorewall Init Package
http://www.shorewall.net/manpages/shorewall-init.html
22. shorewall6-interfaces
http://www.shorewall.net/manpages6/shorewall6-interfaces.html
23. Hairpin packets are packets that are routed out of the same interface that they arrived on.
24. Hairpin packets are packets that are routed out of the same interface that they arrived on.
25. shorewall-tcinterfaces
http://www.shorewall.net/manpages/shorewall-tcinterfaces.html
26. shorewall-tcpri
http://www.shorewall.net/manpages/shorewall-tcpri.html
27. shorewall6-providers
http://www.shorewall.net/manpages6/shorewall6-providers.html
28. shorewall6-tcpri
http://www.shorewall.net/manpages6/shorewall6-tcpri.html
29. shorewall6-rtrules
http://www.shorewall.net/manpages6/shorewall6-rtrules.html
30. shorewall6-routing_rules
http://www.shorewall.net/manpages6/shorewall6-routing_rules.html
Configuration Files 01/21/2016 SHOREWALL6.CONF(5)