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shorewall_code/Shorewall/manpages/shorewall.conf.xml
Tom Eastep 64edd30a76 Correct link in shorewall[6].conf manpages 
Signed-off-by: Tom Eastep <teastep@shorewall.net>
2012-08-21 07:54:51 -07:00

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<?xml version="1.0" encoding="UTF-8"?>
<!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>). If the
<emphasis>value</emphasis> contains shell metacharacters or white-space,
then it must be enclosed in quotes. Example:
MACLIST_LOG_LEVEL="NFLOG(1,0,1)".</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 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.</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 messages to their own log
file.</para>
<para>Beginning with Shorewall 4.4.22, LOGMARK is also a valid level which
logs the packet's mark value along with the other usual information. The
syntax is:</para>
<simplelist>
<member><emphasis
role="bold">LOGMARK[</emphasis><replaceable>(priority)</replaceable><emphasis
role="bold">]</emphasis></member>
</simplelist>
<para>where <replaceable>priority</replaceable> is one of the levels
listed in the list above. If omitted, the default is info (6).</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
role="bold">none</emphasis>}</term>
<listitem>
<para></para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">DROP_DEFAULT=</emphasis>{<emphasis>action</emphasis>|<emphasis
role="bold">none</emphasis>}</term>
<listitem>
<para></para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">NFQUEUE_DEFAULT=</emphasis>{<emphasis>action</emphasis>|<emphasis
role="bold">none</emphasis>}</term>
<listitem>
<para></para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">QUEUE_DEFAULT=</emphasis>{<emphasis>action</emphasis>|<emphasis
role="bold">none</emphasis>}</term>
<listitem>
<para></para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">REJECT_DEFAULT=</emphasis>{<emphasis>action</emphasis>|<emphasis
role="bold">none</emphasis>}</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) <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">ACCOUNTING=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>Added in Shorewall 4.4.7. If set to Yes, Shorewall accounting
is enabled (see <ulink
url="shorewall-accounting.html">shorewall-accounting</ulink>(5)). If
not specified or set to the empty value, ACCOUNTING=Yes is
assumed.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">ACCOUNTING_TABLE=</emphasis>[<emphasis
role="bold">filter</emphasis>|<emphasis
role="bold">mangle</emphasis>]</term>
<listitem>
<para>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 <ulink
url="shorewall-accounting.html">shorewall-accounting</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">AUTOCOMMENT=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>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 &lt;macro name&gt;". The
AUTO_COMMENT option has a default value of 'Yes'.</para>
<para>The setting of the AUTOMAKE option is ignored if the
<command>start</command> or <command>restart</command> command
includes a directory name (e.g.,<command> shorewall restart
/etc/shorewall.new</command>).</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">AUTOHELPERS=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>Added in Shorewall 4.5.7. When set to <option>Yes</option>
(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:</para>
<orderedlist>
<listitem>
<para>Set AUTOHELPERS=No.</para>
</listitem>
<listitem>
<para>Either:</para>
<orderedlist numeration="loweralpha">
<listitem>
<para>Modify <ulink
url="shorewall-conntrack.html">shorewall-conntrack</ulink>
(5) to only apply helpers where they are required; or</para>
</listitem>
<listitem>
<para>Specify the appropriate helper in the HELPER column in
<ulink url="shorewall-rules.html">shorewall-rules</ulink>
(5).</para>
<note>
<para>The macros for those applications requiring a helper
automatically specify the appropriate HELPER where
required.</para>
</note>
</listitem>
</orderedlist>
</listitem>
</orderedlist>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">AUTOMAKE=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>If set, the behavior of the 'start' command is changed; if no
files in /etc/shorewall have been changed since the last successful
<command>start</command> or <command>restart</command> command, then
the compilation step is skipped and the compiled script that
executed the last <command>start</command> or
<command>restart</command> command is used. The default is
AUTOMAKE=No.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">BLACKLIST_DISPOSITION=</emphasis>[<emphasis
role="bold">DROP</emphasis>|A_DROP|<emphasis
role="bold">REJECT|A_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>
<para>A_DROP and A_REJECT are audited versions of DROP and REJECT
respectively and were added in Shorewall 4.4.20. They require
AUDIT_TARGET in the kernel and iptables.</para>
<para>The BLACKLIST_DISPOSITION setting has no effect on entries in
the BLACKLIST section of <ulink
url="shorewall-rules.html">shorewall-rules</ulink> (5). It
determines the disposition of packets sent to the <emphasis
role="bold">blacklog</emphasis> target of <ulink
url="shorewall-blrules.html">shorewall-blrules </ulink>(5).</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. The BLACKLIST_LOGLEVEL setting has no effect on entries in
the BLACKLIST section of <ulink
url="shorewall-rules.html">shorewall-rules</ulink> (5). It
determines the log level of packets sent to the <emphasis
role="bold">blacklog</emphasis> target of <ulink
url="shorewall-blrules.html">shorewall-blrules</ulink>(5).</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. That includes entries in the <ulink
url="???">shorewall-blrules</ulink> (5) file and in the BLACKLIST
section of <ulink url="shorewall-rules.html">shorewall-rules</ulink>
(5).</para>
<para>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">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 who prefer to
configure traffic shaping when the network interfaces come up rather
than when the firewall is started. If that is what you want to do,
set TC_ENABLED=Yes and CLEAR_TC=No and do not supply an
/etc/shorewall/tcstart file. That way, your traffic shaping rules
can still use the “fwmark” classifier based on packet marking
defined in <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">COMPLETE=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>Added in Shorewall 4.4.12. When you set this option to Yes,
you are asserting that the configuration is complete so that your
set of zones encompasses any hosts that can send or receive traffic
to/from/through the firewall. This causes Shorewall to omit the
rules that catch packets in which the source or destination IP
address is outside of any of your zones. Default is No. It is
recommended that this option only be set to Yes if:</para>
<itemizedlist>
<listitem>
<para>You have defined an interface whose effective physical
setting is '+'.</para>
</listitem>
<listitem>
<para>That interface is assigned to a zone.</para>
</listitem>
<listitem>
<para>You have no CONTINUE policies or rules.</para>
</listitem>
</itemizedlist>
</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 "&lt;configuration
directory&gt;" 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">DELETE_THEN_ADD=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>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>Causes Shorewall to not load the listed kernel modules.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">DYNAMIC_BLACKLIST=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>Added in Shorewall 4.4.7. When set to <emphasis
role="bold">No</emphasis> or <emphasis role="bold">no</emphasis>,
dynamic blacklisting using the <command>shorewall drop</command>,
<command>shorewall reject</command>, <command>shorewall
logdrop</command> and <command>shorewall logreject</command> is
disabled. Default is <emphasis role="bold">Yes</emphasis>.</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 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">EXPORTMODULES=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>Added in Shorewall 4.4.17. When set to Yes when compiling for
use by Shorewall Lite (<command>shorewall load</command>,
<command>shorewall reload </command>or <command>shorewall
export</command> 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 <filename>/usr/share/shorewall</filename> but
will copy the found in another location on the CONFIG_PATH.</para>
<para>When compiling for direct use by Shorewall, causes the
contents of the local module or helpers file to be copied into the
compiled script. When set to No or not set, the compiled script
reads the file itself.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">EXPORTPARAMS=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>Deprecated in Shorewall 4.4.17.</para>
<para>Beginning with Shorewall 4.4.17, the variables set in the
'params' file at compile time are available at run time with
EXPORTPARAMS=No. As a consequence, beginning with that version the
recommended setting is EXPORTPARAMS=No.</para>
<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 which is the recommended
setting unless you are using Shorewall Lite.</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>
<note>
<para>FASTACCEPT=Yes is incompatible with
BLACKLISTNEWONLY=No.</para>
</note>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">FORWARD_CLEAR_MARK=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">GEOIPDIR</emphasis>=[<emphasis>pathname</emphasis>]</term>
<listitem>
<para>Added in Shorewall 4.5.4. Specifies the pathname of the
directory containing the <firstterm>GeoIP Match</firstterm>
database. See <ulink
url="http://www.shorewall.net/ISO-3661.html">http://www.shorewall.net/ISO-3661.html</ulink>.
If not specified, the default value is
<filename>/usr/share/xt_geoip/LE</filename> which is the default
location of the little-endian database.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">HELPERS</emphasis>=[<emphasis>helper</emphasis>[,<replaceable>helper</replaceable>...]]</term>
<listitem>
<para>Added in Shorewall 4.5.7. This option lists the Netfilter
application helps that are to be enabled. If not specified, the
default is to enable all helpers.</para>
<para>Possible values for <replaceable>helper</replaceable>
are:</para>
<itemizedlist>
<listitem>
<para>amanda</para>
</listitem>
<listitem>
<para>ftp</para>
</listitem>
<listitem>
<para>h323</para>
</listitem>
<listitem>
<para>irc</para>
</listitem>
<listitem>
<para>netbios-ns</para>
</listitem>
<listitem>
<para>pptp</para>
</listitem>
<listitem>
<para>sane</para>
</listitem>
<listitem>
<para>sip</para>
</listitem>
<listitem>
<para>snmp</para>
</listitem>
<listitem>
<para>tftp</para>
</listitem>
</itemizedlist>
<para>When HELPERS is specified on a system running Kernel 3.5.0 or
later, automatic association of helpers to connections is
disabled.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">HIGH_ROUTE_MARKS=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>Deprecated in Shorewall 4.4.26 in favor of
PROVIDER_OFFSET.</para>
<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 had
a multi-ISP configuration that uses the track option.</para>
<para>You may set HIGH_ROUTE_MARKS=Yes in to effectively divide the
packet mark and connection mark into two mark fields.</para>
<para>The width of the fields are determined by the setting of
WIDE_TC_MARKS. If WIDE_TC_MARKS=No (the default):</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>
</orderedlist>
<para>When WIDE_TC_MARKS=Yes:</para>
<orderedlist numeration="loweralpha">
<listitem>
<para>The MARK field in the providers file must have a value
that is a multiple of 65536 (using hex representation, the
values are 0x010000-0xFF0000 with the low-order 16 bits being
zero).</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 be in the range of
1-16383 and may still not be set in the PREROUTING chain.</para>
</listitem>
</orderedlist>
<para>Regardless of the setting of WIDE_TC_MARKS, when you SAVE or
RESTORE in tcrules, only the TC mark value is saved or restored.
Shorewall handles saving and restoring the routing (provider)
marks.</para>
</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</emphasis>=[<emphasis>pathname</emphasis>]</term>
<listitem>
<para>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.</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=zones</emphasis></term>
<listitem>
<para>This option indicates that zone-related ipsec information is
found in the zones file (<ulink
url="shorewall-zones.html">shorewall-zones</ulink>(5)). The option
indicates to the compiler that this is not a legacy configuration
where the ipsec information was contained in a separate file. The
value of this option must not be changed and the option must not be
deleted.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">IPSET</emphasis>=[<emphasis>pathname</emphasis>]</term>
<listitem>
<para>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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">IPSET_WARNINGS=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>Added in Shorewall 4.5.2. Default is Yes. When set, causes the
rules compiler to issue a warning when:</para>
<itemizedlist>
<listitem>
<para>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.</para>
</listitem>
<listitem>
<para>When [src] is specified in a destination column and when
[dst] is specified in a source column.</para>
</listitem>
</itemizedlist>
</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>When set to <option>Yes</option>, this option prevents
generated scripts 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">LEGACY_FASTSTART=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>Added in Shorewall 4.4.20. If not specified, the default is
Yes which preserves the legacy behavior of <command>start
-f</command> (the modification times of the files in
<filename>/etc/shorewall</filename> are compare with that of
<filename>/var/lib/shorewall/restore)</filename>. If set to No, then
the times are compared with that of /var/lib/shorewall/firewall,
which is consistant with the way that <command>restart -f</command>
works.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">LOAD_HELPERS_ONLY=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>Added in Shorewall 4.4.7. When set to Yes, restricts the set
of modules loaded by shorewall to those listed in
/var/lib/shorewall/helpers and those that are actually used. When
not set, or set to the empty value, LOAD_HELPERS_ONLY=No is
assumed.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">LOCKFILE</emphasis>=[<emphasis>pathname</emphasis>]</term>
<listitem>
<para>Specifies the name of the Shorewall lock file, used to prevent
simultaneous state-changing commands. If not specified,
${VARDIR}/shorewall/lock is assumed (${VARDIR} is normally /var/lib
but can be changed when Shorewall-core is installed -- see the
output of <command>shorewall show vardir</command>).</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
<filename>/proc/sys/net/ipv4/conf/*/log_martians</filename> to 1
with the exception of
<filename>/proc/sys/net/ipv4/conf/all/log_martians which is set to
0</filename>. The default value is <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> 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. For further information, see <ulink
url="http://www.shorewall.net/shorewall_logging.html">http://www.shorewall.net/shorewall_logging.html</ulink>.</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>
<note>
<para>The setting of LOGFORMAT has an effect of the permitted
length of zone names. See <ulink
url="shorewall-zones.html">shorewall-zones</ulink> (5).</para>
</note>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">LOGLIMIT=[</emphasis>[{<emphasis>s</emphasis>|<emphasis
role="bold">d</emphasis>}:]<emphasis>rate</emphasis><emphasis
role="bold">/</emphasis>{<emphasis
role="bold">sec</emphasis>|<emphasis
role="bold">min</emphasis>|<emphasis
role="bold">hour</emphasis>|<emphasis
role="bold">day</emphasis>}[:<emphasis>burst</emphasis>]]</term>
<listitem>
<para>Added in Shorewall 4.4.12. Limits the logging rate, either
overall, or by source or destination IP address.</para>
<para>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.</para>
<para>If <replaceable>burst</replaceable> is not specified, then a
value of 5 is assumed.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">LOGBURST=</emphasis>[<emphasis>burst</emphasis>]</term>
<listitem>
<para>Deprecated in Shorewall 4.4.12.</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>Deprecated in Shorewall 4.4.12. These options are ignored when
LOGLIMIT is specified.</para>
<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. If you supply one of
these, then you should also supply the other.</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, 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>|A_DROP|A_REJECT]</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>
<para>A_DROP and A_REJECT are audited versions of DROP and REJECT
respectively and were added in Shorewall 4.4.20. They require
AUDIT_TARGET in the kernel and iptables.</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 or
MACLIST_DISPOSITION=A_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">MANGLE_ENABLED=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">MAPOLDACTIONS=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>This option is included for compatibility with old Shorewall
configuration. New installs should always have
MAPOLDACTIONS=No.</para>
</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 id="MASK_BITS">
<term><emphasis
role="bold">MASK_BITS</emphasis>=[<replaceable>number</replaceable>]</term>
<listitem>
<para>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 &gt;= TC_BITS and &lt;= PROVIDER_OFFSET (if
PROVIDER_OFFSET &gt; 0). Default value and the default values of the
other mark layout options is determined as follows:</para>
<table frame="none">
<title>Default Packet Mark Layout</title>
<tgroup cols="2">
<tbody>
<row>
<entry>WIDE_TC_MARKS=No, HIGH_ROUTE_MARKS=No</entry>
<entry>TC_BITS=8, PROVIDER_BITS=8, PROVIDER_OFFSET=0,
MASK_BITS=8</entry>
</row>
<row>
<entry>WIDE_TC_MARKS=No, HIGH_ROUTE_MARKS=Yes</entry>
<entry>TC_BITS=8, PROVIDER_BITS=8, PROVIDER_OFFSET=8,
MASK_BITS=8</entry>
</row>
<row>
<entry>WIDE_TC_MARKS=Yes, HIGH_ROUTE_MARKS=No</entry>
<entry>TC_BITS=14, PROVIDER_BITS=8, PROVIDER_OFFSET=0,
MASK_BITS=16</entry>
</row>
<row>
<entry>WIDE_TC_MARKS=Yes, HIGH_ROUTE_MARKS=Yes</entry>
<entry>TC_BITS=14, PROVIDER_BITS=8, PROVIDER_OFFSET=16,
MASK_BITS=16</entry>
</row>
</tbody>
</tgroup>
</table>
</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 "ko ko.gz o o.gz
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>
</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">NFACCT=</emphasis>[<emphasis>pathname</emphasis>]</term>
<listitem>
<para>Added in Shorewall 4.5.7. Specifies the pathname of the nfacct
utiliity. If not specified, Shorewall will use the PATH settting to
find the program.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">NULL_ROUTE_RFC1918=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>When set to Yes, causes Shorewall to null-route the IPv4
address ranges reserved by RFC1918. The default value is
'No'.</para>
<para>When combined with route filtering (ROUTE_FILTER=Yes or
<option>routefilter</option> in <ulink
url="shorewall-interfaces.html">shorewall-interfaces</ulink>(5)),
this option ensures that packets with an RFC1918 source address are
only accepted from interfaces having known routes to networks using
such addresses.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">OPTIMIZE=</emphasis>[<replaceable>value</replaceable>]</term>
<listitem>
<para>The specified <replaceable>value</replaceable> enables certain
optimizations. Each optimization category is associated with a power
of two. To enable multiple optimization categories, simply add their
corresponding numbers together.</para>
<itemizedlist>
<listitem>
<para>Optimization category 1 - 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 the 1 bit
in OPTIMIZE.</para>
<para>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.</para>
</listitem>
<listitem>
<para>Optimization category 2 - Added in Shorewall 4.4.7. When
set, suppresses superfluous ACCEPT rules in a policy chain that
implements an ACCEPT policy. Any ACCEPT rules that immediately
preceed the final blanket ACCEPT rule in the chain are now
omitted.</para>
</listitem>
<listitem>
<para>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:</para>
<itemizedlist>
<listitem>
<para>accounting chains (unless
OPTIMIZE_ACCOUNTING=Yes)</para>
</listitem>
<listitem>
<para>action chains (user-defined)</para>
</listitem>
<listitem>
<para>'blacklst' chain</para>
</listitem>
<listitem>
<para>dynamic</para>
</listitem>
<listitem>
<para>forwardUPnP</para>
</listitem>
<listitem>
<para>UPnP (nat table)</para>
</listitem>
</itemizedlist>
<para>Additionally:</para>
<itemizedlist>
<listitem>
<para>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.</para>
</listitem>
<listitem>
<para>Chains with no references are deleted.</para>
</listitem>
<listitem>
<para>Accounting chains are subject to optimization if the
OPTIMIZE_ACCOUNTING option is set to 'Yes'.</para>
</listitem>
<listitem>
<para>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.</para>
</listitem>
</itemizedlist>
<para>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.</para>
<para>For example, consider this chain:</para>
<programlisting> -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
</programlisting>
<para>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.</para>
</listitem>
<listitem>
<para>Optimization category 8 - Added in Shorewall 4.4.9. When
set, causes chains with identical rules to be collapsed into a
single chain.</para>
</listitem>
<listitem>
<para>Optimization category 16 - Added in Shorewall 4.4.26. When
set, causes sequences of <firstterm>compatible</firstterm> rules
to be combined into a single rule. Rules are considered
compatible if they differ only in their destination ports and
comments.</para>
<para>A sequence of combatible rules is often generated when
macros are invoked in sequence.</para>
<para>The ability to combine adjacent rules is limited by two
factors:</para>
<itemizedlist>
<listitem>
<para>Destination port lists may only be combined up to a
maximum of 15 ports, where a port-pair counts as two
ports.</para>
</listitem>
<listitem>
<para>Rules may only be combined until the length of their
concatinated comment reaches 255 characters.</para>
</listitem>
</itemizedlist>
<para>When either of these limits would be exceeded, the current
combined rule is emitted and the compiler attemts to combine
rules beginning with the one that would have exceeded the limit.
Adjacent combined comments are separated by ', '. Empty comments
at the front of a group of combined comments are replaced by
'Others and'. Empty comments at the end of a group of combined
comments are replaced by 'and others'.</para>
<variablelist>
<varlistentry>
<term>Example 1:</term>
<listitem>
<para>Rules with comments "FOO", &lt;empty&gt; and "BAR"
would result in the combined comment "FOO and others,
BAR".</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example 2:</term>
<listitem>
<para>Rules with comments &lt;empty&gt;, "FOO" and "BAR"
would reult in the combined comment "Others and FOO, BAR".
Note: Optimize level 16 requires "Extended Multi-port
Match" in your iptables and kernel.</para>
</listitem>
</varlistentry>
</variablelist>
</listitem>
</itemizedlist>
<para>The default value is zero which disables all
optimizations.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">OPTIMIZE_ACCOUNTING=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>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.</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">PERL=</emphasis><emphasis>pathname</emphasis></term>
<listitem>
<para>Added in Shorewall 4.4.11 RC1. Specifies the path name of the
Perl executable. Default is <filename>/usr/bin/perl</filename>. If
the pathname specified by this option does not exist or the named
file is not executable, then Shorewall falls back to
<filename>/usr/bin/perl/</filename></para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">PROVIDER_BITS</emphasis>=[<replaceable>number</replaceable>]</term>
<listitem>
<para>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 <link
linkend="MASK_BITS">MASK_BITS</link> above for default value.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">PROVIDER_OFFSET</emphasis>=[<replaceable>number</replaceable>]</term>
<listitem>
<para>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 &gt;= TC_BITS (Shorewall automatically
adjusts PROVIDER_OFFSET's value). PROVIDER_OFFSET + PROVIDER_BITS +
ZONE_BITS must be &lt; 32. See <link
linkend="MASK_BITS">MASK_BITS</link> above for default value.</para>
</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">RELATED_DISPOSITION=[ACCEPT|A_ACCEPT|A_DROP|A_REJECT|DROP|REJECT]</emphasis></term>
<listitem>
<para>Added in Shorewall 4.4.27. Shorewall has traditionally
ACCEPTed RELATED packets that don't match any rule in the RELATED
section of <ulink
url="manpages/shorewall-rules.html">shorewall-rules</ulink> (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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">RELATED_LOG_LEVEL=</emphasis><emphasis>log-level</emphasis></term>
<listitem>
<para>Added in Shorewall 4.4.27. Packets in the related state that
do not match any rule in the RELATED section of <ulink
url="manpages/shorewall-rules.html">shorewall-rules</ulink> (5) are
logged at this level. The default value is empty which means no
logging is performed.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">REQUIRE_INTERFACE=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>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 <ulink
url="shorewall-init.html">Shorewall Init Package</ulink>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">RESTORE_DEFAULT_ROUTE=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>This option determines whether to restore the default route
saved when here are 'balance' providers defined but all of them are
down.</para>
<para>The default is RESTORE_DEFAULT_ROUTE=Yes which preserves the
pre-4.2.6 behavior.</para>
<para>RESTORE_DEFAULT_ROUTE=No is appropriate when you don't want a
default route in the main table (USE_DEFAULT_RT=No) or in the
default table (USE_DEFAULT_RT=Yes) when there are no balance
providers available. In that case, RESTORE_DEFAULT_ROUTE=No will
cause any default route in the relevant table to be deleted.</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">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> 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">RPFILTER_DISPOSITION=</emphasis>[<emphasis
role="bold">DROP</emphasis>|<emphasis
role="bold">REJECT</emphasis>|A_DROP|A_REJECT]</term>
<listitem>
<para>Added in Shorewall 4.5.7. Determines the disposition of
packets entering from interfaces the <option>rpfilter</option>
option (see <ulink
url="shorewall-interfaces.html">shorewall-interfaces</ulink>(5)).
Packets disposed of by this option are those whose response packets
would not be sent through the same interface receiving the
packet.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">RPFILTER_LOG_LEVEL=</emphasis><emphasis>log-level</emphasis></term>
<listitem>
<para>Added in shorewall 4.5.7. Determines the logging of packets
disposed via the RPFILTER_DISPOSITION. The default value is
<option>info</option>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">SAVE_IPSETS=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>Re-enabled in Shorewall 4.4.6. If SAVE_IPSETS=Yes, then the
current contents of your ipsets will be saved by the <emphasis
role="bold">shorewall stop</emphasis> and <emphasis
role="bold">shorewall save</emphasis> commands and restored by the
<emphasis role="bold">shorewall start</emphasis> and <emphasis
role="bold">shorewall restore</emphasis> commands.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">SFILTER_DISPOSITION=</emphasis>[<emphasis
role="bold">DROP</emphasis>|<emphasis
role="bold">REJECT</emphasis>|A_DROP|A_REJECT]</term>
<listitem>
<para>Added in Shorewall 4.4.20. Determines the disposition of
packets matching the <option>sfilter</option> option (see <ulink
url="shorewall-interfaces.html">shorewall-interfaces</ulink>(5)) and
of <firstterm>hairpin</firstterm> packets on interfaces without the
<option>routeback</option> option.<footnote>
<para>Hairpin packets are packets that are routed out of the
same interface that they arrived on.</para>
</footnote> interfaces without the routeback option.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">SFILTER_LOG_LEVEL=</emphasis><emphasis>log-level</emphasis></term>
<listitem>
<para>Added on Shorewall 4.4.20. Determines the logging of packets
matching the <option>sfilter</option> option (see <ulink
url="shorewall-interfaces.html">shorewall-interfaces</ulink>(5)) and
of <firstterm>hairpin</firstterm> packets on interfaces without the
<option>routeback</option> option.<footnote>
<para>Hairpin packets are packets that are routed out of the
same interface that they arrived on.</para>
</footnote> interfaces without the routeback option. The default
is <option>info</option>. If you don't wish for these packets to be
logged, use SFILTER_LOG_LEVEL=none.</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_DISPOSITION=</emphasis>[<emphasis
role="bold">DROP</emphasis>|A_DROP]</term>
<listitem>
<para>Added in Shorewall 4.4.20. The default setting is DROP which
causes smurf packets (see the nosmurfs option in <ulink
url="shorewall-interfaces.html">shorewall-interfaces</ulink>(5)) to
be dropped. A_DROP causes the packets to be audited prior to being
dropped and requires AUDIT_TARGET support in the kernel and
iptables.</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 and OpenSuSE, this
should be set to /var/lock/subsys/shorewall. For Debian, the value
is /var/lock/shorewall and in LEAF it is /var/run/shorwall.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">TC</emphasis>=[<emphasis>pathname</emphasis>]</term>
<listitem>
<para>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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">TC_BITS</emphasis>=[<replaceable>number</replaceable>]</term>
<listitem>
<para>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 <link
linkend="MASK_BITS">MASK_BITS</link> above for default value.</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>|<emphasis
role="bold">Simple</emphasis>|Shared]</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=Simple (Shorewall 4.4.6 and later),
simple traffic shaping using <ulink
url="shorewall-tcinterfaces.html">shorewall-tcinterfaces</ulink>(5)
and <ulink url="shorewall-tcpri.html">shorewall-tcpri</ulink>(5) is
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>
<para>Beginning with Shorewall 4.4.15, you can set
TC_ENABLED=Shared. This allows you to configure the tcdevices and
tcclasses in your Shorewall6 configuration yet make them available
to the compiler when compiling your Shorewall configuration. In
addition to setting TC_ENABLED=Shared, you need to create symbolic
links from your Shorewall configuration directory (normally
/etc/shorewall/) to the tcdevices and tcclasses files in your
Shorewall6 configuration directory (normally
/etc/shorewall6/).</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">TC_PRIOMAP</emphasis>=<emphasis>map</emphasis></term>
<listitem>
<para>Added in Shorewall 4.4.6. Determines the mapping of a packet's
TOS field to priority bands. See <ulink
url="shorewall-tcpri.html">shorewall-tcpri</ulink>(5). The
<emphasis>map</emphasis> 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.</para>
<para>The default setting is TC_PRIOMAP="2 3 3 3 2 3 1 1 2 2 2 2 2 2
2 2".</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>|A_DROP|A_REJECT]</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>
<para>A_DROP and A_REJECT are audited versions of DROP and REJECT
respectively and were added in Shorewall 4.4.20. They require
AUDIT_TARGET in the kernel and iptables.</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">TRACK_PROVIDERS=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>Added in Shorewall 4.4.3. When set to Yes, causes the
<option>track</option> option to be assumed on all providers defined
in <ulink
url="shorewall-providers.html">shorewall-providers</ulink>(5). May
be overridden on an individual provider through use of the
<option>notrack</option> option. The default value is 'No'.</para>
<para>Beginning in Shorewall 4.4.6, setting this option to 'Yes'
also simplifies PREROUTING rules in <ulink
url="shorewall-tcrules.html">shorewall-tcrules</ulink>(5).
Previously, when TC_EXPERT=No, packets arriving through 'tracked'
provider interfaces were unconditionally passed to the PREROUTING
tcrules. This was done so that tcrules could reset the packet mark
to zero, thus allowing the packet to be routed using the 'main'
routing table. Using the main table allowed dynamic routes (such as
those added for VPNs) to be effective. The rtrules file was created
to provide a better alternative to clearing the packet mark. As a
consequence, passing these packets to PREROUTING complicates things
without providing any real benefit. Beginning with Shorewall 4.4.6,
when TRACK_PROVIDERS=Yes and TC_EXPERT=No, packets arriving through
'tracked' interfaces will not be passed to the PREROUTING rules.
Since TRACK_PROVIDERS was just introduced in 4.4.3, this change
should be transparent to most, if not all, users.</para>
</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.<note>
<para><emphasis role="bold">detect</emphasis> may be
specified for interfaces whose configuration is managed by
dhcpcd. Shorewall will use dhcpcd's database to find the
interfaces's gateway.</para>
</note></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">USE_PHYSICAL_NAMES=</emphasis>[<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term>
<listitem>
<para>Added in Shorewall 4.4.27. Normally, when Shorewall creates a
Netfilter chain that relates to an interface, it uses the
interfaces's logical name as the base of the chain name. For
example, if the logical name for an interface is OAKLAND, then the
input chain for traffic arriving on that interface would be
'OAKLAND_in'. If this option is set to Yes, then the physical name
of the interface will be used the base of the chain name.</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>
<varlistentry>
<term><emphasis role="bold">WIDE_TC_MARKS=</emphasis>{<emphasis
role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>}</term>
<listitem>
<para>Deprecated in Shorewall 4.4.26 in favor of TC_BITS and
MASK_BITS.</para>
<para>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).</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">ZONE_BITS</emphasis>=[<replaceable>number</replaceable>]</term>
<listitem>
<para>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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">ZONE2ZONE</emphasis>={<option>2</option>|<option>-</option>}</term>
<listitem>
<para>Added in Shorewall 4.4.4. This option determines how Shorewall
constructs chain names involving zone names and/or 'all'. The
default is '2' (e.g., fw2net).</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-ipsets(5), shorewall-maclist(5), shorewall-masq(5),
shorewall-nat(5), shorewall-netmap(5), shorewall-params(5),
shorewall-policy(5), shorewall-providers(5), shorewall-proxyarp(5),
shorewall-rtrules(5), shorewall-routestopped(5), shorewall-rules(5),
shorewall-tcclasses(5), shorewall-tcdevices(5), shorewall-tcinterfaces(5),
shorewall-tcpri(5), shorewall-tcrules(5), shorewall-tos(5),
shorewall-tunnels(5), shorewall-zones(5)</para>
</refsect1>
</refentry>
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