shorewall_code/Shorewall/manpages/shorewall-providers.xml

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<refentry>
  <refmeta>
    <refentrytitle>shorewall-providers</refentrytitle>

    <manvolnum>5</manvolnum>

    <refmiscinfo>Configuration Files</refmiscinfo>
  </refmeta>

  <refnamediv>
    <refname>providers</refname>

    <refpurpose>Shorewall Providers file</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <cmdsynopsis>
      <command>/etc/shorewall/providers</command>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para>This file is used to define additional routing tables. You will want
    to define an additional table if:</para>

    <itemizedlist>
      <listitem>
        <para>You have connections to more than one ISP or multiple
        connections to the same ISP</para>
      </listitem>

      <listitem>
        <para>You run Squid as a transparent proxy on a host other than the
        firewall.</para>
      </listitem>

      <listitem>
        <para>You have other requirements for policy routing.</para>
      </listitem>
    </itemizedlist>

    <para>Each entry in the file defines a single routing table.</para>

    <para>If you wish to omit a column entry but want to include an entry in
    the next column, use "-" for the omitted entry.</para>

    <para>The columns in the file are as follows.</para>

    <variablelist>
      <varlistentry>
        <term><emphasis role="bold">NAME</emphasis> -
        <emphasis>name</emphasis></term>

        <listitem>
          <para>The provider <emphasis>name</emphasis>. Must be a valid shell
          variable name. The names 'local', 'main', 'default' and 'unspec' are
          reserved and may not be used as provider names.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">NUMBER</emphasis> -
        <emphasis>number</emphasis></term>

        <listitem>
          <para>The provider number -- a number between 1 and 15. Each
          provider must be assigned a unique value.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">MARK</emphasis> (Optional) -
        <emphasis>value</emphasis></term>

        <listitem>
          <para>A FWMARK <emphasis>value</emphasis> used in your <ulink
          url="/manpages/shorewall-mangle.html">shorewall-mangle(5)</ulink>
          file to direct packets to this provider.</para>

          <para>If HIGH_ROUTE_MARKS=Yes in <ulink
          url="/manpages/shorewall.conf.html">shorewall.conf(5)</ulink>, then
          the value must be a multiple of 256 between 256 and 65280 or their
          hexadecimal equivalents (0x0100 and 0xff00 with the low-order byte
          of the value being zero). Otherwise, the value must be between 1 and
          255. Each provider must be assigned a unique mark value. This column
          may be omitted if you don't use packet marking to direct connections
          to a particular provider.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">DUPLICATE</emphasis> -
        <emphasis>routing-table-name</emphasis></term>

        <listitem>
          <para>The name of an existing table to duplicate to create this
          routing table. May be <option>main</option> or the name of a
          previously listed provider. You may select only certain entries from
          the table to copy by using the COPY column below. This column should
          contain a dash ("-') when USE_DEFAULT_RT=Yes in <ulink
          url="/manpages/shorewall.conf.html">shorewall.conf(5)</ulink>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">INTERFACE</emphasis> -
        <emphasis>interface</emphasis>[:<emphasis>address</emphasis>]</term>

        <listitem>
          <para>The name of the network interface to the provider. Must be
          listed in <ulink
          url="/manpages/shorewall-interfaces.html">shorewall-interfaces(5)</ulink>.
          In general, that interface should not have the
          <option>proxyarp</option> option specified unless
          <option>loose</option> is given in the OPTIONS column of this
          entry.</para>

          <para>Where more than one provider is serviced through a single
          interface, the <emphasis>interface</emphasis> must be followed by a
          colon and the IP <emphasis>address</emphasis> of the interface that
          is supplied by the associated provider.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">GATEWAY</emphasis> - {<emphasis
        role="bold">-</emphasis>|<emphasis>address</emphasis>[,<emphasis>mac</emphasis>]|<emphasis
        role="bold">detect</emphasis>}</term>

        <listitem>
          <para>The IP address of the provider's gateway router. Beginning
          with Shorewall 4.6.2, you may also specify the MAC address of the
          gateway when there are multiple providers serviced through the same
          interface. When the MAC is not specified, Shorewall will detect the
          MAC during firewall start or restart.</para>

          <para>You can enter "detect" here and Shorewall will attempt to
          detect the gateway automatically.</para>

          <para>For PPP devices, you may omit this column.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">OPTIONS</emphasis> (Optional) - [<emphasis
        role="bold">-</emphasis>|<emphasis>option</emphasis>[<emphasis
        role="bold">,</emphasis><emphasis>option</emphasis>]...]</term>

        <listitem>
          <para>A comma-separated list selected from the following. The order
          of the options is not significant but the list may contain no
          embedded white-space.</para>

          <variablelist>
            <varlistentry>
              <term>autosrc</term>

              <listitem>
                <para>Added in Shorewall 4.5.17. Causes a host route to the
                provider's gateway router to be added to the provider's
                routing table. This is the default behavior unless overridden
                by a following <emphasis role="bold">noautosrc</emphasis>
                option.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">track</emphasis></term>

              <listitem>
                <para>If specified, inbound connections on this interface are
                to be tracked so that responses may be routed back out this
                same interface.</para>

                <para>You want to specify <option>track</option> if internet
                hosts will be connecting to local servers through this
                provider.</para>

                <para>Beginning with Shorewall 4.4.3, <option>track</option>
                defaults to the setting of the TRACK_PROVIDERS option in
                <ulink
                url="/manpages/shorewall.conf.html">shorewall.conf</ulink>
                (5). If you set TRACK_PROVIDERS=Yes and want to override that
                setting for an individual provider, then specify
                <option>notrack</option> (see below).</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis
              role="bold">balance[=<replaceable>weight</replaceable>]</emphasis></term>

              <listitem>
                <para>The providers that have <option>balance</option>
                specified will get outbound traffic load-balanced among them.
                By default, all interfaces with <option>balance</option>
                specified will have the same weight (1). You can change the
                weight of an interface by specifying
                <option>balance=</option><replaceable>weight</replaceable>
                where <replaceable>weight</replaceable> is the weight of the
                route out of this interface.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">loose</emphasis></term>

              <listitem>
                <para>Shorewall normally adds a routing rule for each IP
                address on an interface which forces traffic whose source is
                that IP address to be sent using the routing table for that
                interface. Setting <option>loose</option> prevents creation of
                such rules on this interface.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis
              role="bold">load=<replaceable>probability</replaceable></emphasis></term>

              <listitem>
                <para>Added in Shorewall 4.6.0. This option provides an
                alternative method of load balancing based on probabilities.
                Providers to be balanced are given a
                <replaceable>probability</replaceable> (a number 0 &gt; n
                &gt;= 1) with up to 8 digits to the right of the decimal
                point. Beginning with Shorewall 4.6.10, a warning is issued if
                the sum of the probabilities is not 1.00000000.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">noautosrc</emphasis></term>

              <listitem>
                <para>Added in Shorewall 4.5.17. Prevents the addition of a
                host route to the provider's gateway router from being added
                to the provider's routing table. This option must be used with
                caution as it can cause start and restart failures.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">notrack</emphasis></term>

              <listitem>
                <para>Added in Shorewall 4.4.3. When specified, turns off
                <option>track</option>.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">optional (deprecated for use with
              providers that do not share an interface)</emphasis></term>

              <listitem>
                <para>If the interface named in the INTERFACE column is not up
                and configured with an IPv4 address then ignore this provider.
                If not specified, the value of the <option>optional</option>
                option for the INTERFACE in <ulink
                url="/manpages/shorewall-interfaces.html">shorewall-interfaces(5)</ulink>
                is assumed. Use of that option is preferred to this one,
                unless an <replaceable>address</replaceable> is provider in
                the INTERFACE column.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">primary</emphasis></term>

              <listitem>
                <para>Added in Shorewall 4.6.6, <emphasis
                role="bold">primary</emphasis> is equivalent to <emphasis
                role="bold">balance=1</emphasis> and is preferred when the
                remaining providers specify <emphasis
                role="bold">fallback</emphasis> or <emphasis
                role="bold">tproxy</emphasis>.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis
              role="bold">src=</emphasis><replaceable>source-address</replaceable></term>

              <listitem>
                <para>Specifies the source address to use when routing to this
                provider and none is known (the local client has bound to the
                0 address). May not be specified when an
                <replaceable>address</replaceable> is given in the INTERFACE
                column. If this option is not used, Shorewall substitutes the
                primary IP address on the interface named in the INTERFACE
                column.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis
              role="bold">mtu=</emphasis><replaceable>number</replaceable></term>

              <listitem>
                <para>Specifies the MTU when forwarding through this provider.
                If not given, the MTU of the interface named in the INTERFACE
                column is assumed.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis
              role="bold">fallback[=<replaceable>weight</replaceable>]</emphasis></term>

              <listitem>
                <para>Indicates that a default route through the provider
                should be added to the default routing table (table 253). If a
                <replaceable>weight</replaceable> is given, a balanced route
                is added with the weight of this provider equal to the
                specified <replaceable>weight</replaceable>. If the option is
                given without a <replaceable>weight</replaceable>, an separate
                default route is added through the provider's gateway; the
                route has a metric equal to the provider's NUMBER.</para>

                <para>Prior to Shorewall 4.4.24, the option is ignored with a
                warning message if USE_DEFAULT_RT=Yes in
                <filename>shorewall.conf</filename>.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">tproxy</emphasis></term>

              <listitem>
                <para>Added in Shorewall 4.5.4. Used for supporting the TPROXY
                action in shorewall-mangle(5). See <ulink
                url="/Shorewall_Squid_Usage.html">http://www.shorewall.net/Shorewall_Squid_Usage.html</ulink>.
                When specified, the MARK, DUPLICATE and GATEWAY columns should
                be empty, INTERFACE should be set to 'lo' and
                <option>tproxy</option> should be the only OPTION. Only one
                <option>tproxy</option> provider is allowed.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">hostroute</emphasis></term>

              <listitem>
                <para>Added in Shorewall 4.5.21. This is the default behavior
                that results in a host route to the defined <emphasis
                role="bold">GATEWAY</emphasis> being inserted into the main
                routing table and into the provider's routing table. <emphasis
                role="bold">hostroute</emphasis> is required for older
                distributions but <emphasis role="bold">nohostroute</emphasis>
                (below) is appropriate for recent distributions. <emphasis
                role="bold">hostroute</emphasis> may interfere with Zebra's
                ability to add routes on some distributions such as Debian
                7.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">nohostroute</emphasis></term>

              <listitem>
                <para>Added in Shorewall 4.5.21. nohostroute inhibits addition
                of a host route to the defined <emphasis
                role="bold">GATEWAY</emphasis> being inserted into the main
                routing table and into the provider's routing table. <emphasis
                role="bold">nohostroute</emphasis> is not appropriate for
                older distributions but is appropriate for recent
                distributions. <emphasis role="bold">nohostroute</emphasis>
                allows Zebra's to correctly add routes on some distributions
                such as Debian 7.</para>
              </listitem>
            </varlistentry>
          </variablelist>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">COPY</emphasis> -
        [{<option>none</option>|<emphasis>interface</emphasis><emphasis
        role="bold">[,</emphasis><emphasis>interface</emphasis>]...}]</term>

        <listitem>
          <para>A comma-separated list of other interfaces on your firewall.
          Wildcards specified using an asterisk ("*") are permitted (e.g.,
          tun* ). Usually used only when DUPLICATE is <option>main</option>.
          Only copy routes through INTERFACE and through interfaces listed
          here. If you only wish to copy routes through INTERFACE, enter
          <option>none</option> in this column.</para>

          <para>Beginning with Shorewall 4.5.17, blackhole, unreachable and
          prohibit routes are no longer copied by default but may be copied by
          including <emphasis role="bold">blackhole</emphasis>,<emphasis
          role="bold">unreachable</emphasis> and <emphasis
          role="bold">prohibit</emphasis> respectively in the COPY
          list.</para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>Examples</title>

    <variablelist>
      <varlistentry>
        <term>Example 1:</term>

        <listitem>
          <para>You run squid in your DMZ on IP address 192.168.2.99. Your DMZ
          interface is eth2</para>

          <programlisting>        #NAME   NUMBER  MARK DUPLICATE  INTERFACE GATEWAY       OPTIONS
        Squid   1       1    -          eth2      192.168.2.99  -</programlisting>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>Example 2:</term>

        <listitem>
          <para>eth0 connects to ISP 1. The IP address of eth0 is
          206.124.146.176 and the ISP's gateway router has IP address
          206.124.146.254.</para>

          <para>eth1 connects to ISP 2. The IP address of eth1 is
          130.252.99.27 and the ISP's gateway router has IP address
          130.252.99.254.</para>

          <para>eth2 connects to a local network.</para>

          <programlisting>        #NAME NUMBER MARK DUPLICATE INTERFACE GATEWAY          OPTIONS            COPY
        ISP1  1       1    main      eth0      206.124.146.254 track,balance      eth2
        ISP2  2       2    main      eth1      130.252.99.254  track,balance      eth2</programlisting>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>FILES</title>

    <para>/etc/shorewall/providers</para>
  </refsect1>

  <refsect1>
    <title>See ALSO</title>

    <para><ulink
    url="/MultiISP.html">http://www.shorewall.net/MultiISP.html</ulink></para>

    <para><ulink
    url="/configuration_file_basics.htm#Pairs">http://www.shorewall.net/configuration_file_basics.htm#Pairs</ulink></para>

    <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-proxyarp(5), shorewall-rtrules(5),
    shorewall-routestopped(5), shorewall-rules(5), shorewall.conf(5),
    shorewall-secmarks(5), shorewall-tcclasses(5), shorewall-tcdevices(5),
    shorewall-mangle(5), shorewall-tos(5), shorewall-tunnels(5),
    shorewall-zones(5)</para>
  </refsect1>
</refentry>