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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
"http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd">
<refentry>
<refmeta>
<refentrytitle>shorewall.conf</refentrytitle>
<manvolnum>5</manvolnum>
</refmeta>
<refnamediv>
<refname>shorewall.conf</refname>
<refpurpose>Shorewall global configuration file</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>/etc/shorewall/shorewall.conf</command>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>This file sets options that apply to Shorewall as a whole.</para>
<para>The file consists of Shell comments (lines beginning with '#'),
blank lines and assignment statements
(<emphasis>variable</emphasis>=<emphasis>value</emphasis>).</para>
</refsect1>
<refsect1>
<title>OPTIONS</title>
<para>Many options have as their value a <emphasis>log-level</emphasis>.
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.</para>
<para>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.</para>
<para>Valid levels are:</para>
<programlisting> 7 debug
6 info
5 notice
4 warning
3 err
2 crit
1 alert
0 emerg</programlisting>
<para>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 specifify. If you are unsure of the
level to choose, 6 (info) is a safe bet. You may specify levels by name or
by number.</para>
<para>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 <ulink
url="http://www.netfilter.org/projects/ulogd/index.html">http://www.netfilter.org/projects/ulogd/index.html</ulink>
and can be configured to log all Shorewall message to their own log
file</para>
<para>The following options may be set in shorewall.conf.</para>
<variablelist>
<varlistentry>
<term><emphasis
role="bold">ACCEPT_DEFAULT=</emphasis>{<emphasis>action</emphasis>|<emphasis>macro</emphasis>|<emphasis
role="bold">none</emphasis>}</term>
<listitem>
<para></para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">DROP_DEFAULT=</emphasis>{<emphasis>action</emphasis>|<emphasis>macro</emphasis>|<emphasis
role="bold">none</emphasis>}</term>
<listitem>
<para></para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">REJECT_DEFAULT=</emphasis>{<emphasis>action</emphasis>|<emphasis>macro</emphasis>|<emphasis
role="bold">none</emphasis>}</term>
<listitem>
<para></para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">QUEUE_DEFAULT=</emphasis>{<emphasis>action</emphasis>|<emphasis>macro</emphasis>|<emphasis
role="bold">none</emphasis>}</term>
<listitem>
<para></para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">NFQUEUE_DEFAULT=</emphasis>{<emphasis>action</emphasis>|<emphasis>macro</emphasis>|<emphasis
role="bold">none</emphasis>} (Shorewall-perl 4.0.3 and later)</term>
<listitem>
<para>In earlier Shorewall versions, a "default action" for DROP and
REJECT policies was specified in the file
/usr/share/shorewall/actions.std.</para>
<para>To allow for default rules to be applied when USE_ACTIONS=No,
the DROP_DEFAULT, REJECT_DEFAULT, ACCEPT_DEFAULT, QUEUE_DEFAULT and
NFQUEUE_DEFAULT options have been added.</para>
<para>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.</para>
<para>The value applied to these may be:</para>
<simplelist>
<member>a) The name of an
<replaceable>action</replaceable>.</member>
<member>b) The name of a <replaceable>macro</replaceable>
(Shorewall-shell only)</member>
<member>c) <emphasis role="bold">None</emphasis> or <emphasis
role="bold">none</emphasis></member>
</simplelist>
<para>The default values are:</para>
<simplelist>
<member>DROP_DEFAULT="Drop"</member>
<member>REJECT_DEFAULT="Reject"</member>
<member>ACCEPT_DEFAULT="none"</member>
<member>QUEUE_DEFAULT="none"</member>
<member>NFQUEUE_DEFAULT="None"</member>
</simplelist>
<para>If USE_ACTIONS=Yes, then these values refer to action.Drop and
action.Reject respectively. If USE_ACTIONS=No, then these values
refer to macro.Drop and macro.Reject.</para>
<para>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 <ulink
url="shorewall-policy.html">shorewall-policy</ulink>(5).</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">ADD_IP_ALIASES=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>This parameter determines whether Shorewall automatically adds
the external address(es) in <ulink
url="shorewall-nat.html">shorewall-nat</ulink>(5). If the variable
is set to <emphasis role="bold">Yes</emphasis> or <emphasis
role="bold">yes</emphasis> then Shorewall automatically adds these
aliases. If it is set to <emphasis role="bold">No</emphasis> or
<emphasis role="bold">no</emphasis>, you must add these aliases
yourself using your distribution's network configuration
tools.</para>
<para>If this variable is not set or is given an empty value
(ADD_IP_ALIASES="") then ADD_IP_ALIASES=Yes is assumed.</para>
<warning>
<para>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.</para>
</warning>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">ADD_SNAT_ALIASES=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>This parameter determines whether Shorewall automatically adds
the SNAT ADDRESS in <ulink
url="shorewall-masq.html">shorewall-masq</ulink>(5). If the variable
is set to <emphasis role="bold">Yes</emphasis> or <emphasis
role="bold">yes</emphasis> then Shorewall automatically adds these
addresses. If it is set to <emphasis role="bold">No</emphasis> or
<emphasis role="bold">no</emphasis>, you must add these addresses
yourself using your distribution's network configuration
tools.</para>
<para>If this variable is not set or is given an empty value
(ADD_SNAT_ALIASES="") then ADD_SNAT_ALIASES=No is assumed.</para>
<warning>
<para>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.</para>
</warning>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">ADMINISABSENTMINDED=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>The value of this variable affects Shorewall's stopped state.
When ADMINISABSENTMINDED=No, only traffic to/from those addresses
listed in <ulink
url="shorewall-routestopped.html">shorewall-routestopped</ulink>(5)
is accepted when Shorewall is stopped. When ADMINISABSENTMINDED=Yes,
in addition to traffic to/from addresses in <ulink
url="shorewall-routestopped.html">shorewall-routestopped</ulink>(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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">AUTO_COMMENT=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>Added in Shorewall-perl 4.1.5. 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'.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">BIGDPORTLISTS=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>Setting this option to 'Yes' allows you to include arbitrarily
long destination port lists in all configuration files.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">BLACKLIST_DISPOSITION=</emphasis>[<emphasis
role="bold">DROP</emphasis>|<emphasis
role="bold">REJECT</emphasis>]</term>
<listitem>
<para>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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">BLACKLIST_LOGLEVEL=</emphasis>[<emphasis>log-level</emphasis>]</term>
<listitem>
<para>This parameter determines if packets from blacklisted hosts
are logged and it determines the syslog level that they are to be
logged at. Its value is a syslog level (Example:
BLACKLIST_LOGLEVEL=debug). If you do not assign a value or if you
assign an empty value then packets from blacklisted hosts are not
logged.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">BLACKLISTNEWONLY=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>When set to <emphasis role="bold">Yes</emphasis> or <emphasis
role="bold">yes</emphasis>, blacklists are only consulted for new
connections. When set to <emphasis role="bold">No</emphasis> or
<emphasis role="bold">no</emphasis>, blacklists are consulted for
every packet (will slow down your firewall noticably if you have
large blacklists). If the BLACKLISTNEWONLY option is not set or is
set to the empty value then BLACKLISTNEWONLY=No is assumed.</para>
<note>
<para>BLACKLISTNEWONLY=No is incompatible with
FASTACCEPT=Yes.</para>
</note>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">BRIDGING=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>When set to <emphasis role="bold">Yes</emphasis> or <emphasis
role="bold">yes</emphasis>, enables Shorewall Bridging
support.</para>
<para><note>
<para>BRIDGING=Yes may not work properly with Linux kernel
2.6.20 or later and is not supported by Shorewall-perl.</para>
</note></para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">CLAMPMSS=[</emphasis><emphasis
role="bold">Yes</emphasis>|<emphasis
role="bold">No</emphasis>|<emphasis>value</emphasis>]</term>
<listitem>
<para>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 <emphasis
role="bold">Yes</emphasis> or <emphasis role="bold">yes</emphasis>,
the feature is enabled. If left blank or set to <emphasis
role="bold">No</emphasis> or <emphasis role="bold">no</emphasis>,
the feature is not enabled.</para>
<para><emphasis role="bold">Important</emphasis>: This option
requires CONFIG_IP_NF_TARGET_TCPMSS in your kernel.</para>
<para>You may also set CLAMPMSS to a numeric
<emphasis>value</emphasis> (e.g., CLAMPMSS=1400). This will set the
MSS field in TCP SYN packets going through the firewall to the
<emphasis>value</emphasis> that you specify.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">CLEAR_TC=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>If this option is set to <emphasis role="bold">No</emphasis>
then Shorewall won't clear the current traffic control rules during
[re]start. This setting is intended for use by people that prefer to
configure traffic shaping when the network interfaces come up rather
than when the firewall is started. If that is what you want to do,
set TC_ENABLED=Yes and CLEAR_TC=No and do not supply an
/etc/shorewall/tcstart file. That way, your traffic shaping rules
can still use the “fwmark” classifier based on packet marking
defined in <ulink
url="shorewall-tcrules.html">shorewall-tcrules</ulink>(5). If not
specified, CLEAR_TC=Yes is assumed.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">CONFIG_PATH</emphasis>=[<emphasis>directory</emphasis>[:<emphasis>directory</emphasis>]...]</term>
<listitem>
<para>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:</para>
<itemizedlist>
<listitem>
<para>If the command is "try" or a "<configuration
directory>" was specified in the command (e.g.,
<command>shorewall check ./gateway</command>) then the directory
given in the command is searched first.</para>
</listitem>
<listitem>
<para>Next, each directory in the CONFIG_PATH setting is
searched in sequence.</para>
</listitem>
</itemizedlist>
<blockquote>
<para></para>
<para>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.</para>
<para>Note that the setting in /usr/share/shorewall/configpath is
always used to locate shorewall.conf.</para>
</blockquote>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">DELAYBLACKLISTLOAD=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>Users with a large static black list (<ulink
url="shorewall-blacklist.html">shorewall-blacklist</ulink>(5)) may
want to set the DELAYBLACKLISTLOAD option to <emphasis
role="bold">Yes</emphasis>. When DELAYBLACKLISTLOAD=Yes, Shorewall
will enable new connections before loading the blacklist rules.
While this may allow connections from blacklisted hosts to slip by
during construction of the blacklist, it can substantially reduce
the time that all new connections are disabled during <emphasis
role="bold">shorewall</emphasis> [<emphasis
role="bold">re</emphasis>]<emphasis
role="bold">start</emphasis>.</para>
<note>
<para>DELAYBLACKLISTLOAD=Yes is not supported by
Shorewall-perl.</para>
</note>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">DELETE_THEN_ADD=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>Added in Shorewall 4.0.4. 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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">DETECT_DNAT_IPADDRS=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>If set to <emphasis role="bold">Yes</emphasis> or <emphasis
role="bold">yes</emphasis>, 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 <emphasis role="bold">No</emphasis> or <emphasis
role="bold">no</emphasis>, 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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">DISABLE_IPV6=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>If set to <emphasis role="bold">Yes</emphasis> or <emphasis
role="bold">yes</emphasis>, IPv6 traffic to, from and through the
firewall system is disabled. If set to <emphasis
role="bold">No</emphasis> or <emphasis role="bold">no</emphasis>,
Shorewall will take no action with respect to allowing or
disallowing IPv6 traffic. If not specified or empty,
“DISABLE_IPV6=No” is assumed.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">DONT_LOAD=</emphasis>[<emphasis>module</emphasis>[,<emphasis>module</emphasis>]...]</term>
<listitem>
<para>Added in Shorewall-4.0.6. Causes Shorewall to not load the
listed modules.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">DYNAMIC_ZONES=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>When set to <emphasis role="bold">Yes</emphasis> or <emphasis
role="bold">yes</emphasis>, enables dynamic zones. DYNAMIC_ZONES=Yes
is not allowed in configurations that will run under Shorewall
Lite.</para>
<para>DYNAMIC_ZONES=Yes is not supported by Shorewall-perl 4.2.0 and
later.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">EXPAND_POLICIES=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>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<programlisting>#SOURCE DEST POLICY LOG
# LEVEL
net all DROP info</programlisting>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-perl
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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">EXPORTPARAMS=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>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.</para>
<para>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.</para>
<para>The default is EXPORTPARAMS=Yes</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">FASTACCEPT=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>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.</para>
<para>If you set FASTACCEPT=Yes, then ESTABLISHED/RELEATED packets
are accepted early in the INPUT, FORWARD and OUTPUT chains. If you
set FASTACCEPT=Yes then you may not include rules in the ESTABLISHED
or RELATED sections of <ulink
url="shorewall-rules.html">shorewall-rules</ulink>(5).</para>
<para></para>
<note>
<para>FASTACCEPT=Yes is incompatible with
BLACKLISTNEWONLY=No.</para>
</note>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">HIGH_ROUTE_MARKS=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>Prior to version 3.2.0, it was not possible to use connection
marking in <ulink
url="shorewall-tcrules.html">shorewall-tcrules</ulink>(5) if you
have a multi-ISP configuration that uses the track option.</para>
<para>Beginning with release 3.2.0, you may now set
HIGH_ROUTE_MARKS=Yes in to effectively divide the packet mark and
connection mark into two 8-byte mark fields.</para>
<para>When you do this:</para>
<orderedlist numeration="loweralpha">
<listitem>
<para>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).</para>
</listitem>
<listitem>
<para>You may only set those mark values in the PREROUTING
chain.</para>
</listitem>
<listitem>
<para>Marks used for traffic shaping must still be in the range
of 1-255 and may still not be set in the PREROUTING
chain.</para>
</listitem>
<listitem>
<para>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.</para>
</listitem>
</orderedlist>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">IMPLICIT_CONTINUE=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>When this option is set to <emphasis
role="bold">Yes</emphasis>, it causes subzones to be treated
differently with respect to policies.</para>
<para>Subzones are defined by following their name with ":" and a
list of parent zones (in <ulink
url="shorewall-zones.html">shorewall-zones</ulink>(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
<ulink url="shorewall-nesting.html">shorewall-nesting</ulink>(5).
With IMPLICIT_CONTINUE=Yes, that happens automatically.</para>
<para>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).</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">IP_FORWARDING=</emphasis>[<emphasis
role="bold">On</emphasis>|<emphasis
role="bold">Off</emphasis>|<emphasis
role="bold">Keep</emphasis>]</term>
<listitem>
<para>This parameter determines whether Shorewall enables or
disables IPV4 Packet Forwarding (/proc/sys/net/ipv4/ip_forward).
Possible values are:</para>
<variablelist>
<varlistentry>
<term><emphasis role="bold">On</emphasis> or <emphasis
role="bold">on</emphasis></term>
<listitem>
<para>packet forwarding will be enabled.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">Off</emphasis> or <emphasis
role="bold">off</emphasis></term>
<listitem>
<para>packet forwarding will be disabled.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">Keep</emphasis> or <emphasis
role="bold">keep</emphasis></term>
<listitem>
<para>Shorewall will neither enable nor disable packet
forwarding.</para>
</listitem>
</varlistentry>
</variablelist>
<para></para>
<blockquote>
<para>If this variable is not set or is given an empty value
(IP_FORWARD="") then IP_FORWARD=On is assumed.</para>
</blockquote>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">IPSECFILE=</emphasis>{<emphasis
role="bold">zones</emphasis>|<emphasis
role="bold">ipsec</emphasis>}</term>
<listitem>
<para>This should be set to <emphasis role="bold">zones</emphasis>
for all new Shorewall installations. IPSECFILE=ipsec is only used
for compatibility with pre-Shorewall-3.0 configurations.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">IPTABLES=</emphasis>[<emphasis>pathname</emphasis>]</term>
<listitem>
<para>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.</para>
<para>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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">KEEP_RT_TABLES=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>Added in Shorewall 4.0.3. When set to <option>Yes</option>,
this option prevents scripts generated by Shorewall-perl from
altering the /etc/iproute2/rt_tables database when there are entries
in <filename>/etc/shorewall/providers</filename>. If you set this
option to <option>Yes</option> while Shorewall (Shorewall-lite) is
running, you should remove the file
<filename>/var/lib/shorewall/rt_tables</filename>
(<filename>/var/lib/shorewall-lite/rt_tables</filename>) before your
next <command>stop</command>, <command>refresh</command>,
<command>restore</command> on <command>restart</command>
command.</para>
<para>The default is KEEP_RT_TABLES=No.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">LOG_MARTIANS=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis
role="bold">No</emphasis>|Keep]</term>
<listitem>
<para>If set to <emphasis role="bold">Yes</emphasis> or <emphasis
role="bold">yes</emphasis>, sets
/proc/sys/net/ipv4/conf/all/log_martians and
/proc/sys/net/ipv4/conf/default/log_martians to 1. In Shorewall
versions prior to 4.1.5, the default is <emphasis
role="bold">No</emphasis> which sets both of the above to zero. In
Shorewall 4.1.5, the default value was chaned to <emphasis
role="bold">Yes</emphasis> 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 <emphasis
role="bold">logmartians</emphasis> interface option in <ulink
url="shorewall-interfaces.html">shorewall-interfaces</ulink>(5).</para>
<para>The value <emphasis role="bold">Keep</emphasis> is only
allowed under Shorewall-perl. It causes Shorewall to ignore the
option. If the option is set to <emphasis
role="bold">Yes</emphasis>, then martians are logged on all
interfaces. If the option is set to <emphasis
role="bold">No</emphasis>, then martian logging is disabled on all
interfaces except those specified in <ulink
url="shorewall-interfaces.html">shorewall-interfaces</ulink>(5).</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">LOG_VERBOSITY=</emphasis>[<emphasis>number</emphasis>]</term>
<listitem>
<para>This option controls the amount of information logged to the
file specified in the STARTUP_LOG option.</para>
<para>Values are:</para>
<simplelist>
<member>-1 - Logging is disabled</member>
<member>0 - Silent. Only error messages are logged.</member>
<member>1 - Major progress messages logged.</member>
<member>2 - All progress messages logged</member>
</simplelist>
<para>If not specified, then -1 is assumed.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">LOGALLNEW=</emphasis>[<emphasis>log-level</emphasis>]</term>
<listitem>
<para>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.</para>
<itemizedlist>
<listitem>
<para>The table name is used as the chain name in the log
prefix.</para>
</listitem>
<listitem>
<para>The chain name is used as the target in the log
prefix.</para>
</listitem>
</itemizedlist>
<para></para>
<blockquote>
<para>For example, using the default LOGFORMAT, the log prefix for
logging from the nat table's PREROUTING chain is:</para>
<programlisting> Shorewall:nat:PREROUTING
</programlisting>
<important>
<para>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.</para>
</important>
<para></para>
<caution>
<para>Do not use this option if the resulting log messages will
be sent to another system.</para>
</caution>
</blockquote>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">LOGFILE=</emphasis>[<emphasis>pathname</emphasis>]</term>
<listitem>
<para>This parameter tells the /sbin/shorewall program where to look
for Shorewall messages when processing the <emphasis
role="bold">dump</emphasis>, <emphasis
role="bold">logwatch</emphasis>, <emphasis role="bold">show
log</emphasis>, and <emphasis role="bold">hits</emphasis> commands.
If not assigned or if assigned an empty value, /var/log/messages is
assumed.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">LOGFORMAT=</emphasis>[<emphasis
role="bold">"</emphasis><emphasis>formattemplate</emphasis><emphasis
role="bold">"</emphasis>]</term>
<listitem>
<para>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:</para>
<programlisting> LOGFORMAT="fp=%s:%d a=%s "</programlisting>
<para>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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">LOGBURST=</emphasis>[<emphasis>burst</emphasis>]</term>
<listitem>
<para></para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">LOGRATE=</emphasis>[<emphasis>rate</emphasis>/{<emphasis
role="bold">minute</emphasis>|<emphasis
role="bold">second</emphasis>}]</term>
<listitem>
<para>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.</para>
<para>Example:</para>
<programlisting> LOGRATE=10/minute
LOGBURST=5</programlisting>
<para>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
which passes without matching a packet, 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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">LOGTAGONLY=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">MACLIST_DISPOSITION=</emphasis>[<emphasis
role="bold">ACCEPT</emphasis>|<emphasis
role="bold">DROP</emphasis>|<emphasis
role="bold">REJECT</emphasis>]</term>
<listitem>
<para>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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">MACLIST_LOG_LEVEL=</emphasis>[<emphasis>log-level</emphasis>]</term>
<listitem>
<para>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="").</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">MACLIST_TABLE=</emphasis>[<emphasis
role="bold">filter</emphasis>|<emphasis
role="bold">mangle</emphasis>]</term>
<listitem>
<para>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.</para>
<para>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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">MACLIST_TTL=[</emphasis><emphasis>number</emphasis>]</term>
<listitem>
<para>The performance of configurations with a large numbers of
entries in <ulink
url="shorewall-maclist.html">shorewall-maclist</ulink>(5) can be
improved by setting the MACLIST_TTL variable in <ulink
url="shorewall.conf.html">shorewall.conf</ulink>(5).</para>
<para>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.</para>
<para>When a new connection arrives from a 'maclist' interface, the
packet passes through then list of entries for that interface in
<ulink url="shorewall-maclist.html">shorewall-maclist</ulink>(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.</para>
<para>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).</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">MAPOLDACTIONS=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>Previously, Shorewall included a large number of standard
actions (AllowPing, AllowFTP, ...). These have been replaced with
parameterized macros. For compatibility, Shorewall can map the old
names into invocations of the new macros if you set
MAPOLDACTIONS=Yes. If this option is not set or is set to the empty
value (MAPOLDACTIONS="") then MAPOLDACTIONS=Yes is assumed.</para>
<para></para>
<note>
<para>MAPOLDACTIONS=Yes is not supported by Shorewall-perl. With
Shorewall-perl, if MAPOLDACTIONS is not set or is set to the ampty
value then MAPOLDACTIONS=No is assumed.</para>
</note>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">MARK_IN_FORWARD_CHAIN=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>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 <emphasis
role="bold">/sbin/shorewall show mangle</emphasis> 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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">MODULE_SUFFIX=</emphasis>[<emphasis
role="bold">"</emphasis><emphasis>extension</emphasis> ...<emphasis
role="bold">"</emphasis>]</term>
<listitem>
<para>The value of this option determines the possible file
extensions of kernel modules. The default value is "o gz ko
o.gz".</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">MODULESDIR=</emphasis>[<emphasis>pathname</emphasis>[<emphasis
role="bold">:</emphasis><emphasis>pathname</emphasis>]...]</term>
<listitem>
<para>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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">MULTICAST=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>This option will normally be set to 'No' (the default). It
should be set to 'Yes' under the following circumstances:</para>
<orderedlist>
<listitem>
<para>You have an interface that has parallel zones defined via
/etc/shorewall/hosts.</para>
</listitem>
<listitem>
<para>You want to forward multicast packets to two or more of
those parallel zones.</para>
</listitem>
</orderedlist>
<para>In such cases, you will configure a <option>destonly</option>
network on each zone receiving multicasts.</para>
<para>The MULTICAST option is only recognized by Shorewall-perl and
is ignored by Shorewall-shell.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">MUTEX_TIMEOUT=</emphasis>[<emphasis>seconds</emphasis>]</term>
<listitem>
<para>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.</para>
<para>If not set or set to the empty value, a value of 60 (60
seconds) is assumed.</para>
<para>An appropriate value for this parameter would be twice the
length of time that it takes your firewall system to process a
<emphasis role="bold">shorewall restart</emphasis> command.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">OPTIMIZE=</emphasis>[<emphasis
role="bold">0</emphasis>|<emphasis role="bold">1</emphasis>]</term>
<listitem>
<para>Traditionally, Shorewall has created rules for <ulink
url="../ScalabilityAndPerformance.html">the complete matrix of host
groups defined by the zones, interfaces and hosts files</ulink>. 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.</para>
<para>These extra rules can be eliminated by setting
OPTIMIZE=1.</para>
<para>The OPTIMIZE 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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">PATH=</emphasis><emphasis>pathname</emphasis>[<emphasis
role="bold">:</emphasis><emphasis>pathname</emphasis>]...</term>
<listitem>
<para>Determines the order in which Shorewall searches directories
for executable files.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">PKTTYPE=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>Normally Shorewall attempts to use the iptables packet type
match extension to determine broadcast and multicast packets.</para>
<orderedlist>
<listitem>
<para>This can cause a message to appear during shorewall start
(modprobe: cant locate module ipt_pkttype).</para>
</listitem>
<listitem>
<para>Some users have found problems with the packet match
extension with the result that their firewall log is flooded
with messages relating to broadcast packets.</para>
</listitem>
</orderedlist>
<para></para>
<blockquote>
<para>If you are experiencing either of these problems, setting
PKTTYPE=No will prevent Shorewall from trying to use the packet
type match extension and to use IP address matching to determine
which packets are broadcasts or multicasts.</para>
</blockquote>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">RCP_COMMAND="</emphasis><replaceable>command</replaceable><emphasis
role="bold">"</emphasis></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">RSH_COMMAND="</emphasis><replaceable>command</replaceable><emphasis
role="bold">"</emphasis></term>
<listitem>
<para>Eariler generations of Shorewall Lite required that remote
root login via ssh be enabled in order to use the
<command>load</command> and <command>reload</command> 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:<simplelist>
<member>RSH_COMMAND</member>
<member>RCP_COMMAND</member>
</simplelist>The default values for these are as
follows:<simplelist>
<member>RSH_COMMAND: ssh ${root}@${system} ${command}</member>
<member>RCP_COMMAND: scp ${files}
${root}@${system}:${destination}</member>
</simplelist>Shell variables that will be set when the commands
are envoked are as follows:<simplelist>
<member><replaceable>root</replaceable> - root user. Normally
<option>root</option> but may be overridden using the '-r'
option.</member>
<member><replaceable>system</replaceable> - The name/IP address
of the remote firewall system.</member>
<member><replaceable>command</replaceable> - For RSH_COMMAND,
the command to be executed on the firewall system.</member>
<member><replaceable>files</replaceable> - For RCP_COMMAND, a
space-separated list of files to be copied to the remote
firewall system.</member>
<member><replaceable>destination</replaceable> - The directory
on the remote system that the files are to be copied
into.</member>
</simplelist></para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">RESTOREFILE=</emphasis><emphasis>filename</emphasis></term>
<listitem>
<para>Specifies the simple name of a file in /var/lib/shorewall to
be used as the default restore script in the <emphasis
role="bold">shorewall save</emphasis>, <emphasis
role="bold">shorewall restore</emphasis>, <emphasis
role="bold">shorewall forget </emphasis>and <emphasis
role="bold">shorewall -f start</emphasis> commands.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">RETAIN_ALIASES=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>During <emphasis role="bold">shorewall star</emphasis>t, IP
addresses to be added as a consequence of ADD_IP_ALIASES=Yes and
ADD_SNAT_ALIASES=Yes are quietly deleted when <ulink
url="shorewall-nat.html">shorewall-nat</ulink>(5) and <ulink
url="shorewall-masq.html">shorewall-masq</ulink>(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 <emphasis role="bold">shorewall start</emphasis> are
still deleted at a subsequent <emphasis role="bold">shorewall
stop</emphasis> or <emphasis role="bold">shorewall
restart</emphasis>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">RFC1918_LOG_LEVEL=</emphasis>[<emphasis>log-level</emphasis>]</term>
<listitem>
<para>This parameter determines the level at which packets logged
under the <emphasis role="bold">norfc1918</emphasis> mechanism are
logged. The value must be a valid syslog level and if no level is
given, then info is assumed.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">RFC1918_STRICT=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>Traditionally, the RETURN target in the 'rfc1918' file has
caused norfc1918 processing to cease for a packet if the packet's
source IP address matches the rule. Thus, if you have this entry in
<ulink
url="shorewall-rfc1918.html">shorewall-rfc1918</ulink>(5):</para>
<programlisting> #SUBNETS TARGET
192.168.1.0/24 RETURN</programlisting>
<para>then traffic from 192.168.1.4 to 10.0.3.9 will be accepted
even though you also have:</para>
<programlisting> #SUBNETS TARGET
10.0.0.0/8 logdrop</programlisting>
<para>Setting RFC1918_STRICT=Yes in shorewall.conf will cause such
traffic to be logged and dropped since while the packet's source
matches the RETURN rule, the packet's destination matches the
'logdrop' rule.</para>
<para>If not specified or specified as empty (e.g.,
RFC1918_STRICT="") then RFC1918_STRICT=No is assumed.</para>
<para></para>
<warning>
<para>RFC1918_STRICT=Yes requires that your kernel and iptables
support 'Connection Tracking' match.</para>
</warning>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">ROUTE_FILTER=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis
role="bold">No</emphasis>|Keep]</term>
<listitem>
<para>If this parameter is given the value <emphasis
role="bold">Yes</emphasis> or <emphasis role="bold">yes</emphasis>
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 <emphasis
role="bold">no</emphasis>.</para>
<para>The value <emphasis role="bold">Keep</emphasis> is only
allowed under Shorewall-perl. It causes Shorewall to ignore the
option. If the option is set to <emphasis
role="bold">Yes</emphasis>, then route filtering occurs on all
interfaces. If the option is set to <emphasis
role="bold">No</emphasis>, then route filtering is disabled on all
interfaces except those specified in <ulink
url="shorewall-interfaces.html">shorewall-interfaces</ulink>(5).</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">SAVE_IPSETS=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>If SAVE_IPSETS=Yes, then the current contents of your ipsets
will be saved by the <emphasis role="bold">shorewall save</emphasis>
command. Regardless of the setting of SAVE_IPSETS, if saved ipset
contents are available then they will be restored by <emphasis
role="bold">shorewall restore</emphasis>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">SHOREWALL_COMPILER=</emphasis>{<emphasis
role="bold">perl</emphasis>|<emphasis
role="bold">shell</emphasis>}</term>
<listitem>
<para>Specifies the compiler to use to generate firewall scripts
when both compilers are installed. The value of this option can be
either <option>perl</option> or <option>shell</option>. If both
compilers are installed and SHOREWALL_SHELL is not set, then
SHOREWALL_SHELL=shell is assumed.</para>
<para>If you add 'SHOREWALL_COMPILER=perl' to
<filename>/etc/shorewall/shorewall.conf</filename> then by default,
the Shorewall-perl compiler will be used on the system. If you add
it to <filename>shorewall.conf</filename> in a separate directory
(such as a Shorewall-lite export directory) then the Shorewall-perl
compiler will only be used when you compile from that
directory.</para>
<para>If you only install one compiler, it is suggested that you do
not set SHOREWALL_COMPILER.</para>
<para>This setting may be overriden in those commands that invoke
the compiler by using the -C command option (see <ulink
url="shorewall.html">shorewall</ulink>(8)).</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">SHOREWALL_SHELL=</emphasis>[<emphasis>pathname</emphasis>]</term>
<listitem>
<para>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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">SMURF_LOG_LEVEL=</emphasis>[<emphasis>log-level</emphasis>]</term>
<listitem>
<para>Specifies the logging level for smurf packets (see the
nosmurfs option in <ulink
url="shorewall-interfaces.html">shorewall-interfaces</ulink>(5)). If
set to the empty value ( SMURF_LOG_LEVEL="" ) then smurfs are not
logged.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">STARTUP_ENABLED=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>Determines if Shorewall is allowed to start. As released from
shorewall.net, this option is set to <emphasis
role="bold">No</emphasis>. When set to <emphasis
role="bold">Yes</emphasis> or <emphasis role="bold">yes</emphasis>,
Shorewall may be started. Used as a guard against Shorewall being
accidentally started before it has been configured.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">STARTUP_LOG=</emphasis>[<emphasis>pathname</emphasis>]</term>
<listitem>
<para>If specified, determines where Shorewall will log the details
of each <emphasis role="bold">start</emphasis>, <emphasis
role="bold">restart</emphasis> and <emphasis
role="bold">refresh</emphasis> command. Logging verbosity is
determined by the setting of LOG_VERBOSITY above.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">SUBSYSLOCK=</emphasis>[<emphasis>pathname</emphasis>]</term>
<listitem>
<para>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, this should be set to
/var/lock/subsys/shorewall. For Debian, the value is
/var/state/shorewall and in LEAF it is /var/run/shorwall.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">TC_ENABLED=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis
role="bold">No</emphasis>|<emphasis
role="bold">Internal</emphasis>]</term>
<listitem>
<para>If you say <emphasis role="bold">Yes</emphasis> or <emphasis
role="bold">yes</emphasis> 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.</para>
<para>If you say <emphasis role="bold">No</emphasis> or <emphasis
role="bold">no</emphasis> then traffic shaping is not
enabled.</para>
<para>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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">TC_EXPERT=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>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 <ulink
url="shorewall-providers.html">shorewall-providers</ulink>(5).</para>
<para>If you know what you are doing, you can set TC_EXPERT=Yes and
Shorewall will not include these cautionary checks.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">TCP_FLAGS_DISPOSITION=</emphasis>[<emphasis
role="bold">ACCEPT</emphasis>|<emphasis
role="bold">DROP</emphasis>|<emphasis
role="bold">REJECT</emphasis>]</term>
<listitem>
<para>Determines the disposition of TCP packets that fail the checks
enabled by the <emphasis role="bold">tcpflags</emphasis> interface
option (see <ulink
url="shorewall-interfaces.html">shorewall-interfaces</ulink>(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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">TCP_FLAGS_LOG_LEVEL=</emphasis>[<emphasis>log-level</emphasis>]</term>
<listitem>
<para>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="").</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">USE_ACTIONS=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>While Shorewall Actions can be very useful, they also require
a sizable amount of code to implement. By setting USE_ACTIONS=No,
embedded Shorewall installations can omit the large library
/usr/share/shorewall-shell/lib.actions.</para>
<note>
<para>USE_ACTIONS=No is not supported by Shorewall-perl.</para>
</note>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">USE_DEFAULT_RT=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>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.</para>
<para>When USE_DEFAULT_RT=Yes:</para>
<orderedlist>
<listitem>
<para>Both the DUPLICATE and the COPY columns in <ulink
url="shorewall-providers.html">providers</ulink>(5) file must
remain empty (or contain "-").</para>
</listitem>
<listitem>
<para>The default route is added to the the 'default' table
rather than to the main table.</para>
</listitem>
<listitem>
<para><emphasis role="bold">balance</emphasis> is assumed unless
<emphasis role="bold">loose</emphasis> is specified.</para>
</listitem>
<listitem>
<para>Packets are sent through the main routing table by a rule
with priority 999. In <ulink
url="shorewall-routing_rules.html">routing_rules</ulink>(5), the
range 1-998 may be used for inserting rules that bypass the main
table.</para>
</listitem>
<listitem>
<para>All provider gateways must be specified explicitly in the
GATEWAY column. <emphasis role="bold">detect</emphasis> may not
be specified.</para>
</listitem>
<listitem>
<para>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).</para>
</listitem>
</orderedlist>
<para>If USE_DEFAULT_RT is not set or if it is set to the empty
string then USE_DEFAULT_RT=No is assumed.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">VERBOSITY=</emphasis>[<emphasis>number</emphasis>]</term>
<listitem>
<para>Shorewall has traditionally been very noisy (produced lots of
output). You may set the default level of verbosity using the
VERBOSITY OPTION.</para>
<para>Values are:</para>
<simplelist>
<member>0 - Silent. You may make it more verbose using the -v
option</member>
<member>1 - Major progress messages displayed</member>
<member>2 - All progress messages displayed (pre Shorewall-3.2.0
behavior)</member>
</simplelist>
<para>If not specified, then 2 is assumed.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>FILES</title>
<para>/etc/shorewall/shorewall.conf</para>
</refsect1>
<refsect1>
<title>See ALSO</title>
<para>shorewall(8), shorewall-accounting(5), shorewall-actions(5),
shorewall-blacklist(5), shorewall-hosts(5), shorewall-interfaces(5),
shorewall-ipsec(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-route_rules(5), shorewall-routestopped(5), shorewall-rules(5),
shorewall-tcclasses(5), shorewall-tcdevices(5), shorewall-tcrules(5),
shorewall-tos(5), shorewall-tunnels(5), shorewall-zones(5)</para>
</refsect1>
</refentry>