<?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/> </listitem> </varlistentry> <varlistentry> <term><emphasis role="bold">DROP_DEFAULT=</emphasis>{<emphasis>action</emphasis>|<emphasis role="bold">none</emphasis>}</term> <listitem> <para/> </listitem> </varlistentry> <varlistentry> <term><emphasis role="bold">NFQUEUE_DEFAULT=</emphasis>{<emphasis>action</emphasis>|<emphasis role="bold">none</emphasis>}</term> <listitem> <para/> </listitem> </varlistentry> <varlistentry> <term><emphasis role="bold">QUEUE_DEFAULT=</emphasis>{<emphasis>action</emphasis>|<emphasis role="bold">none</emphasis>}</term> <listitem> <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">AUTO_COMMENT=</emphasis>[<emphasis role="bold">Yes</emphasis>|<emphasis role="bold">No</emphasis>]</term> <listitem> <para>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> <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">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 "<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>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/ISOCODES.html">http://www.shorewall.net/ISOCODES.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">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/> <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/> <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/> <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 >= TC_BITS and <= PROVIDER_OFFSET (if PROVIDER_OFFSET > 0). Default value and the default values of the other mark layout options is determined as follows:</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">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", <empty> 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 <empty>, "FOO" and "BAR" would reult in the combined comment "Others and FOO, BAR". Note: Optimize level 16 requires "Extended Multi-port Match" in your iptables and kernel.</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 >= TC_BITS (Shorewall automatically adjusts PROVIDER_OFFSET's value). PROVIDER_OFFSET + PROVIDER_BITS + ZONE_BITS must be < 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/> </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">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>filter</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>filter</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>