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<refentry>
  <refmeta>
    <refentrytitle>shorewall6-hosts</refentrytitle>

    <manvolnum>5</manvolnum>

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

  <refnamediv>
    <refname>hosts</refname>

    <refpurpose>shorewall6 file</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <cmdsynopsis>
      <command>/etc/shorewall6/hosts</command>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para>This file is used to define zones in terms of subnets and/or
    individual IP addresses. Most simple setups don't need to (should not)
    place anything in this file.</para>

    <para>The order of entries in this file is not significant in determining
    zone composition. Rather, the order that the zones are declared in <ulink
    url="/manpages6/shorewall6-zones.html">shorewall6-zones</ulink>(5)
    determines the order in which the records in this file are
    interpreted.</para>

    <warning>
      <para>The only time that you need this file is when you have more than
      one zone connected through a single interface.</para>
    </warning>

    <warning>
      <para>If you have an entry for a zone and interface in <ulink
      url="/manpages6/shorewall6-interfaces.html">shorewall6-interfaces</ulink>(5)
      then do not include any entries in this file for that same (zone,
      interface) pair.</para>
    </warning>

    <para>The columns in the file are as follows (where the column name is
    followed by a different name in parentheses, the different name is used in
    the alternate specification syntax).</para>

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

        <listitem>
          <para>The name of a zone declared in <ulink
          url="/manpages6/shorewall6-zones.html">shorewall6-zones</ulink>(5).
          You may not list the firewall zone in this column.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">HOST(S)</emphasis> (hosts)-
        <emphasis>interface</emphasis>:{<replaceable>address-or-range</replaceable>[,<replaceable>address-or-range</replaceable>]...|+<replaceable>ipset</replaceable>|<option>dynamic</option>}[<replaceable>exclusion</replaceable>]</term>

        <listitem>
          <para>The name of an interface defined in the <ulink
          url="/manpages6/shorewall6-interfaces.html">shorewall6-interfaces</ulink>(5)
          file followed by a colon (":") and a comma-separated list whose
          elements are either:</para>

          <orderedlist numeration="loweralpha">
            <listitem>
              <para>The IPv6 <replaceable>address</replaceable> of a
              host.</para>
            </listitem>

            <listitem>
              <para>A network in CIDR format.</para>
            </listitem>

            <listitem>
              <para>An IP address range of the form
              [<emphasis>low.address</emphasis>]-[<emphasis>high.address</emphasis>].
              Your kernel and ip6tables must have iprange match
              support.</para>
            </listitem>

            <listitem>
              <para>The name of an <emphasis>ipset</emphasis>.</para>
            </listitem>

            <listitem>
              <para>The word <option>dynamic</option> which makes the zone
              dynamic in that you can use the <command>shorewall add</command>
              and <command>shorewall delete</command> commands to change to
              composition of the zone. This capability was added in Shorewall
              4.4.21.</para>
            </listitem>
          </orderedlist>

          <blockquote>
            <para>You may also exclude certain hosts through use of an
            <emphasis>exclusion</emphasis> (see <ulink
            url="/manpages6/shorewall6-exclusion.html">shorewall6-exclusion</ulink>(5).</para>
          </blockquote>
        </listitem>
      </varlistentry>

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

        <listitem>
          <para>An optional comma-separated list of options from the following
          list. The order in which you list the options is not significant but
          the list must have no embedded white-space.</para>

          <variablelist>
            <varlistentry>
              <term><emphasis role="bold">blacklist</emphasis></term>

              <listitem>
                <para>Check packets arriving on this port against the <ulink
                url="/manpages6/shorewall6-blacklist.html">shorewall6-blacklist</ulink>(5)
                file.</para>
              </listitem>
            </varlistentry>

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

              <listitem>
                <para>The zone is accessed via a kernel 2.6 ipsec SA. Note
                that if the zone named in the ZONE column is specified as an
                IPSEC zone in the <ulink
                url="/manpages6/shorewall6-zones.html">shorewall6-zones</ulink>(5)
                file then you do NOT need to specify the 'ipsec' option
                here.</para>
              </listitem>
            </varlistentry>

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

              <listitem>
                <para>Added in Shorewall 4.5.2. When present, causes the TCP
                mss for new connections to/from the hosts given in the HOST(S)
                column to be clamped at the specified
                <replaceable>mss</replaceable>.</para>
              </listitem>
            </varlistentry>

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

              <listitem>
                <para>shorewall6 should set up the infrastructure to pass
                packets from this/these address(es) back to themselves. This
                is necessary if hosts in this group use the services of a
                transparent proxy that is a member of the group or if DNAT is
                used to send requests originating from this group to a server
                in the group.</para>
              </listitem>
            </varlistentry>

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

              <listitem>
                <para>Packets arriving from these hosts are checked for
                certain illegal combinations of TCP flags. Packets found to
                have such a combination of flags are handled according to the
                setting of TCP_FLAGS_DISPOSITION after having been logged
                according to the setting of TCP_FLAGS_LOG_LEVEL.</para>
              </listitem>
            </varlistentry>
          </variablelist>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>FILES</title>

    <para>/etc/shorewall6/hosts</para>
  </refsect1>

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

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

    <para>shorewall6(8), shorewall6-accounting(5), shorewall6-actions(5),
    shorewall6-blacklist(5), shorewall6-interfaces(5), shorewall6-maclist(5),
    shorewall6-netmap(5),shorewall6-params(5), shorewall6-policy(5),
    shorewall6-providers(5), shorewall6-rtrules(5),
    shorewall6-routestopped(5), shorewall6-rules(5), shorewall6.conf(5),
    shorewall6-secmarks(5), shorewall6-tcclasses(5), shorewall6-tcdevices(5),
    shorewall6-mangle(5), shorewall6-tos(5), shorewall6-tunnels(5),
    shorewall-zones(5)</para>
  </refsect1>
</refentry>