shorewall_code/manpages/shorewall-zones.xml

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

    <manvolnum>5</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>zones</refname>

    <refpurpose>Shorewall zone declaration file</refpurpose>
  </refnamediv>

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

  <refsect1>
    <title>Description</title>

    <para>The /etc/shorewall/zones file declares your network zones. You
    specify the hosts in each zone through entries in
    <filename>/etc/shorewall/interfaces</filename> or
    <filename>/etc/shorewall/hosts</filename>.</para>

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

    <variablelist>
      <varlistentry>
        <term><emphasis role="bold">ZONE</emphasis> -
        <emphasis>zone</emphasis>[<emphasis
        role="bold">:</emphasis><emphasis>parent-zone</emphasis>[<emphasis
        role="bold">,</emphasis><emphasis>parent-zone</emphasis>]...]</term>

        <listitem>
          <para>Name of the <emphasis>zone</emphasis>. Must start with a
          letter and consist of letters, digits or '_'. The names "all",
          "none", "any", "SOURCE" and "DEST" are reserved and may not be used
          as zone names. The maximum length of a zone name is determined by
          the setting of the LOGFORMAT option in <ulink
          url="shorewall.conf.html">shorewall.conf</ulink>(5). With the
          default LOGFORMAT, zone names can be at most 5 characters
          long.</para>

          <blockquote>
            <para>The maximum length of an iptables log prefix is 29 bytes. As
            explained in <ulink
            url="shorewall.conf.html">shorewall.conf</ulink> (5), the default
            LOGPREFIX formatting string is “Shorewall:%s:%s:” where the first
            %s is replaced by the chain name and the second is replaced by the
            disposition.</para>

            <itemizedlist>
              <listitem>
                <para>The default formatting string has 12 fixed characters
                ("Shorewall" and three colons).</para>
              </listitem>

              <listitem>
                <para>The longest of the standard dispositions are ACCEPT and
                REJECT which have 6 characters each.</para>
              </listitem>

              <listitem>
                <para>The canonical name for the chain containing the rules
                for traffic going from zone 1 to zone 2 is "&lt;zone
                1&gt;2&lt;zone 2&gt;" or "&lt;zone 1&gt;-&lt;zone
                2&gt;".</para>
              </listitem>

              <listitem>
                <para>So if M is the maximum zone name length, such chains can
                have length 2*M + 1.</para>

                <simplelist>
                  <member>12 + 6 + 2*M + 1 = 29 which reduces to</member>

                  <member>2*M = 29 - 12 - 6 - 1 = 10 or</member>

                  <member>M = 5</member>
                </simplelist>
              </listitem>
            </itemizedlist>
          </blockquote>

          <para>The order in which Shorewall matches addresses from packets to
          zones is determined by the order of zone declarations. Where a zone
          is nested in one or more other zones, you may either ensure that the
          nested zone precedes its parents in this file, or you may follow the
          (sub)zone name by ":" and a comma-separated list of the parent
          zones. The parent zones must have been declared in earlier records
          in this file. See <ulink
          url="shorewall-nesting.html">shorewall-nesting</ulink>(5) for
          additional information.</para>

          <para>Example:</para>

          <programlisting>#ZONE     TYPE     OPTIONS         IN OPTIONS        OUT OPTIONS
a         ipv4
b         ipv4
c:a,b     ipv4</programlisting>

          <para>Currently, Shorewall uses this information to reorder the zone
          list so that parent zones appear after their subzones in the list.
          The IMPLICIT_CONTINUE option in <ulink
          url="shorewall.conf.html">shorewall.conf</ulink>(5) can also create
          implicit CONTINUE policies to/from the subzone.</para>

          <para>Where an <emphasis role="bold">ipsec</emphasis> zone is
          explicitly included as a child of an <emphasis
          role="bold">ipv4</emphasis> zone, the ruleset allows CONTINUE
          policies (explicit or implicit) to work as expected.</para>

          <para>In the future, Shorewall may make additional use of nesting
          information.</para>
        </listitem>
      </varlistentry>

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

        <listitem>
          <variablelist>
            <varlistentry>
              <term><emphasis role="bold">ipv4</emphasis></term>

              <listitem>
                <para>This is the standard Shorewall zone type and is the
                default if you leave this column empty or if you enter "-" in
                the column. Communication with some zone hosts may be
                encrypted. Encrypted hosts are designated using the
                'ipsec'option in <ulink
                url="shorewall-hosts.html">shorewall-hosts</ulink>(5).</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">ipsec</emphasis> (or <emphasis
              role="bold">ipsec4</emphasis>)</term>

              <listitem>
                <para>Communication with all zone hosts is encrypted. Your
                kernel and iptables must include policy match support.</para>
              </listitem>
            </varlistentry>

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

              <listitem>
                <para>Designates the firewall itself. You must have exactly
                one 'firewall' zone. No options are permitted with a
                'firewall' zone. The name that you enter in the ZONE column
                will be stored in the shell variable $FW which you may use in
                other configuration files to designate the firewall
                zone.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">bport</emphasis> (or <emphasis
              role="bold">bport4</emphasis>)</term>

              <listitem>
                <para>The zone is associated with one or more ports on a
                single bridge.</para>
              </listitem>
            </varlistentry>

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

              <listitem>
                <para>Added in Shorewall 4.4.11 Beta 2 - A zone composed of
                Linux-vserver guests. The zone contents must be defined in
                <ulink url="shorewall-hosts.html">shorewall-hosts</ulink>
                (5).</para>

                <para>Vserver zones are implicitly handled as subzones of the
                firewall zone.</para>
              </listitem>
            </varlistentry>
          </variablelist>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">OPTIONS, IN OPTIONS and OUT
        OPTIONS</emphasis> - [<emphasis>option</emphasis>[<emphasis
        role="bold">,</emphasis><emphasis>option</emphasis>]...]</term>

        <listitem>
          <para>A comma-separated list of options. With the exception of the
          <option>mss</option> option, these only apply to TYPE
          <option>ipsec</option> zones.</para>

          <variablelist>
            <varlistentry>
              <term><emphasis
              role="bold">reqid=</emphasis><emphasis>number</emphasis></term>

              <listitem>
                <para>where <emphasis>number</emphasis> is specified using
                setkey(8) using the 'unique:<emphasis>number</emphasis> option
                for the SPD level.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">spi=</emphasis>&lt;number&gt;</term>

              <listitem>
                <para>where <emphasis>number</emphasis> is the SPI of the SA
                used to encrypt/decrypt packets.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">proto=</emphasis><emphasis
              role="bold">ah</emphasis>|<emphasis
              role="bold">esp</emphasis>|<emphasis
              role="bold">ipcomp</emphasis></term>

              <listitem>
                <para>IPSEC Encapsulation Protocol</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis
              role="bold">mss=</emphasis><emphasis>number</emphasis></term>

              <listitem>
                <para>sets the MSS field in TCP packets. If you supply this
                option, you should also set FASTACCEPT=No in <ulink
                url="shorewall.conf.html">shorewall.conf</ulink>(5) to insure
                that both the SYN and SYN,ACK packets have their MSS field
                adjusted.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">mode=</emphasis><emphasis
              role="bold">transport</emphasis>|<emphasis
              role="bold">tunnel</emphasis></term>

              <listitem>
                <para>IPSEC mode</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis
              role="bold">tunnel-src=</emphasis><emphasis>address</emphasis>[/<emphasis>mask</emphasis>]</term>

              <listitem>
                <para>only available with mode=tunnel</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis
              role="bold">tunnel-dst=</emphasis><emphasis>address</emphasis>[/<emphasis>mask</emphasis>]</term>

              <listitem>
                <para>only available with mode=tunnel</para>
              </listitem>
            </varlistentry>

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

              <listitem>
                <para>Means that packets must match all rules.</para>
              </listitem>
            </varlistentry>

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

              <listitem>
                <para>Separates rules; can only be used with strict</para>
              </listitem>
            </varlistentry>
          </variablelist>

          <para>The options in the OPTIONS column are applied to both incoming
          and outgoing traffic. The IN OPTIONS are applied to incoming traffic
          (in addition to OPTIONS) and the OUT OPTIONS are applied to outgoing
          traffic.</para>

          <para>If you wish to leave a column empty but need to make an entry
          in a following column, use "-".</para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>FILES</title>

    <para>/etc/shorewall/zones</para>
  </refsect1>

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

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

    <para>shorewall(8), shorewall-accounting(5), shorewall-actions(5),
    shorewall-blacklist(5), shorewall-hosts(5), shorewall-interfaces(5),
    shorewall-maclist(5), shorewall-masq(5), shorewall-nat(5),
    shorewall-nesting(8), shorewall-netmap(5), shorewall-params(5),
    shorewall-policy(5), shorewall-providers(5), shorewall-proxyarp(5),
    shorewall-route_rules(5), shorewall-routestopped(5), shorewall-rules(5),
    shorewall.conf(5), shorewall-tcclasses(5), shorewall-tcdevices(5),
    shorewall-tcrules(5), shorewall-tos(5), shorewall-tunnels(5)</para>
  </refsect1>
</refentry>