shorewall_code/Shorewall-docs2/upgrade_issues.xml

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<article id="upgrade_issues">
  <articleinfo>
    <title>Upgrade Issues</title>

    <author>
      <firstname>Tom</firstname>

      <surname>Eastep</surname>
    </author>

    <pubdate><?dbtimestamp format="Y/m/d"?></pubdate>

    <copyright>
      <year>2002</year>

      <year>2003</year>

      <year>2004</year>

      <holder>Thomas M. Eastep</holder>
    </copyright>

    <legalnotice>
      <para>Permission is granted to copy, distribute and/or modify this
      document under the terms of the GNU Free Documentation License, Version
      1.2 or any later version published by the Free Software Foundation; with
      no Invariant Sections, with no Front-Cover, and with no Back-Cover
      Texts. A copy of the license is included in the section entitled
      <quote><ulink type="" url="copyright.htm">GNU Free Documentation
      License</ulink></quote>.</para>
    </legalnotice>
  </articleinfo>

  <section>
    <title>Important</title>

    <para>It is important that you read all of the sections on this page where
    the version number mentioned in the section title is later than what you
    are currently running.</para>

    <para>In the descriptions that follows, the term
    <emphasis>group</emphasis> refers to a particular network or subnetwork
    (which may be <literal>0.0.0.0/0</literal> or it may be a host address)
    accessed through a particular interface.</para>

    <para>Examples:</para>

    <simplelist columns="1" type="vert">
      <member><literal>eth0:0.0.0.0/0</literal></member>

      <member><literal>eth2:192.168.1.0/24</literal></member>

      <member><literal>eth3:192.0.2.123</literal></member>
    </simplelist>

    <para>You can use the <command moreinfo="none">shorewall check</command>
    command to see the groups associated with each of your zones.</para>
  </section>

  <section>
    <title>Version &gt;= 2.2.0</title>

    <para></para>

    <orderedlist>
      <listitem>
        <para>Shorewall configuration files except shorewall.conf are now
        empty (they contain only comments). If you wish to retain the defaults
        in any of the following files, you should copy these files before
        upgrading them then restore them after the upgrade:</para>

        <simplelist>
          <member>/etc/shorewall/zones</member>

          <member>/etc/shorewall/policy</member>

          <member>/etc/shorewall/tos</member>
        </simplelist>
      </listitem>

      <listitem>
        <para>The following builtin actions have been removed and have been
        replaced by the new action logging implementation described in the new
        features below.</para>

        <simplelist>
          <member>logNotSyn</member>

          <member>rLogNotSyn</member>

          <member>dLogNotSyn</member>
        </simplelist>
      </listitem>

      <listitem>
        <para>If shorewall.conf is upgraded to the latest version, it needs to
        be modified to set STARTUP_ENABLED=Yes.</para>
      </listitem>

      <listitem>
        <para>The Leaf/Bering version of Shorewall was previously
        named:</para>

        <simplelist>
          <member>shorwall-&lt;version&gt;.lrp</member>
        </simplelist>

        <para>Beginning with 2.1, that file will now be named:</para>

        <simplelist>
          <member>shorewall-lrp-&lt;version&gt;.tgz</member>
        </simplelist>

        <para>Simply rename that file to 'shorwall.lrp' when installing it on
        your LEAF/Bering system.</para>
      </listitem>

      <listitem>
        <para>The ORIGINAL DEST column of the /etc/shorewall/rules file may no
        longer contain a second (SNAT) address. You must use an entry in
        /etc/shorewall/masq instead.</para>

        <para>Example from Shorewall FAQ #1:</para>

        <blockquote>
          <para>Prior to Shorewall 2.1:</para>

          <para>/etc/shorewall/interfaces</para>

          <programlisting>#ZONE     INTERFACE      BROADCAST     OPTIONS
loc       eth1           detect        routeback</programlisting>

          <para>/etc/shorewall/rules</para>

          <programlisting>#ACTION  SOURCE   DEST             PROTO   DEST PORT   SOURCE  ORIGINAL
#                                                      PORT    DEST
DNAT     loc      loc:192.168.1.12 tcp     80          -       130.252.100.69:192.168.1.254  </programlisting>

          <para>Shorewall 2.1 and Later:</para>

          <para>/etc/shorewall/interfaces</para>

          <programlisting>#ZONE     INTERFACE      BROADCAST     OPTIONS
loc       eth1           detect        routeback</programlisting>

          <para>/etc/shorewall/masq:</para>

          <programlisting>#INTERFACE     SUBNETS      ADDRESS        PROTO    PORT(S)
eth1           eth1         192.168.1.254  tcp      80</programlisting>

          <para>/etc/shorewall/rules:</para>

          <programlisting>#ACTION  SOURCE   DEST             PROTO   DEST PORT   SOURCE  ORIGINAL
#                                                      PORT    DEST
DNAT     loc      loc:192.168.1.12 tcp     80          -       130.252.100.69</programlisting>
        </blockquote>
      </listitem>

      <listitem>
        <para>The 'logunclean' and 'dropunclean' options that were deprecated
        in Shorewall 2.0 have now been removed completely.</para>
      </listitem>

      <listitem>
        <para>The default port for 'openvpn' tunnels (/etc/shorewall/tunnels)
        has been changed to 1194 to match a similar change in the OpenVPN
        product. The IANA has registered port 1194 for use by OpenVPN.</para>
      </listitem>

      <listitem>
        <para> A new IPTABLES variable has been added to shorewall.conf. This
        variable names the iptables executable that Shorewall will use. The
        variable is set to "/sbin/iptables". If you use the new
        shorewall.conf, you may need to change this setting to maintain
        compabibility with your current setup (if you use your existing
        shorewall.conf that does not set IPTABLES then you should experience
        no change in behavior).</para>
      </listitem>
    </orderedlist>
  </section>

  <section>
    <title>Version &gt;= 2.0.2 RC1</title>

    <itemizedlist>
      <listitem>
        <para>If you are upgrading from Shorewall 1.4.x and you have commands
        in your <filename>/etc/shorewall/common</filename> file that are not
        directly related to the <emphasis role="bold">common</emphasis> chain
        then you will want to move those commands to
        <filename>/etc/shorewall/initdone</filename>.</para>
      </listitem>
    </itemizedlist>
  </section>

  <section>
    <title>Version &gt;= 2.0.2 Beta 1</title>

    <itemizedlist>
      <listitem>
        <para>Extension Scripts - In order for extension scripts to work
        properly with the new iptables-save/restore integration introduced in
        Shorewall 2.0.2 Beta 1, some change may be required to your extension
        scripts.</para>

        <para>If your extension scripts are executing commands other than
        <command>iptables</command> then those commands must also be written
        to the restore file (a temporary file in <filename
        class="directory">/var/lib/shorewall</filename> that is renamed
        <filename>/var/lib/shorewall/restore-base</filename> at the
        completeion of the <filename>/sbin/shorewall</filename> command). The
        following functions should be of help:</para>

        <orderedlist>
          <listitem>
            <para>save_command() -- saves the passed command to the restore
            file.</para>

            <para>Example: <programlisting>save_command echo Operation Complete</programlisting></para>

            <para>That command would simply write "echo Operation Complete" to
            the restore file.</para>
          </listitem>

          <listitem>
            <para>run_and_save_command() -- saves the passed command to the
            restore file then executes it. The return value is the exit status
            of the command. Example: <programlisting>run_and_save_command "echo 1 &gt; /proc/sys/net/ipv4/icmp_echo_ignore_all"</programlisting></para>

            <para>Note that as in this example, when the command involves file
            redirection then the entire command must be enclosed in quotes.
            This applies to all of the functions described here.</para>
          </listitem>

          <listitem>
            <para>ensure_and_save_command() -- runs the passed command. If the
            command fails, the firewall is restored to it's prior saved state
            and the operation is terminated. If the command succeeds, the
            command is written to the restore file</para>
          </listitem>
        </orderedlist>
      </listitem>

      <listitem>
        <para>Dynamic Zone support. - If you don't need to use the
        <command>shorewall add</command> and <command>shorewall
        delete</command> commands, you should set DYNAMIC_ZONES=No in
        <filename>/etc/shorewall/shorewall.conf</filename>.</para>
      </listitem>
    </itemizedlist>
  </section>

  <section>
    <title>Version &gt;= 2.0.1</title>

    <itemizedlist>
      <listitem>
        <para>The function of 'norfc1918' is now split between that option and
        a new 'nobogons' option. The rfc1918 file released with Shorewall now
        contains entries for only those three address ranges reserved by RFC
        1918. A 'nobogons' interface option has been added which handles bogon
        source addresses (those which are reserved by the IANA, those reserved
        for DHCP auto-configuration and the class C test-net reserved for
        testing and documentation examples). This will allow users to perform
        RFC 1918 filtering without having to deal with out of date data from
        IANA. Those who are willing to update their
        <filename>/usr/share/shorewall/bogons</filename> file regularly can
        specify the 'nobogons' option in addition to 'norfc1918'. The level at
        which bogon packets are logged is specified in the new BOGON_LOG_LEVEL
        variable in shorewall.conf. If that option is not specified or is
        specified as empty (e.g, BOGON_LOG_LEVEL="") then bogon packets whose
        TARGET is 'logdrop' in
        <filename>/usr/share/shorewall/bogons</filename> are logged at the
        'info' level.</para>
      </listitem>
    </itemizedlist>
  </section>

  <section>
    <title>VERSION &gt;= 2.0.0-Beta1</title>

    <itemizedlist>
      <listitem>
        <para>The 'dropunclean' and 'logunclean' interface options are no
        longer supported. If either option is specified in
        <filename>/etc/shorewall/interfaces</filename>, a threatening message
        will be generated.</para>
      </listitem>

      <listitem>
        <para>The NAT_BEFORE_RULES option has been removed from
        <filename>shorewall.conf</filename>. The behavior of Shorewall 2.0 is
        as if NAT_BEFORE_RULES=No had been specified. In other words, DNAT
        rules now always take precidence over one-to-one NAT
        specifications.</para>
      </listitem>

      <listitem>
        <para>The default value for the ALL INTERFACES column in
        <filename>/etc/shorewall/nat</filename> has changed. In Shorewall 1.*,
        if the column was left empty, a value of "Yes" was assumed. This has
        been changed so that a value of "No" is now assumed.</para>
      </listitem>

      <listitem>
        <para>The following files don't exist in Shorewall 2.0:</para>

        <simplelist>
          <member><filename>/etc/shorewall/common.def</filename></member>

          <member><filename>/etc/shorewall/common</filename></member>

          <member><filename>/etc/shorewall/icmpdef</filename></member>

          <member><filename>/etc/shorewall/action.template</filename> (moved
          to
          <filename>/usr/share/shorewall/action.template</filename>)</member>
        </simplelist>

        <para>The <filename>/etc/shorewall/action</filename> file now allows
        an action to be designated as the "common" action for a particular
        policy type by following the action name with ":" and the policy
        (DROP, REJECT or ACCEPT).</para>

        <para>The file /usr/share/shorewall/actions.std has been added to
        define those actions that are released as part of Shorewall 2.0 In
        that file are two actions as follows:</para>

        <simplelist>
          <member>Drop:DROP</member>

          <member>Reject:REJECT</member>
        </simplelist>

        <para>The <quote>Drop</quote> action is the common action for DROP
        policies while the <quote>Reject</quote> action is the default action
        for REJECT policies. These actions will be performed on packets prior
        to applying the DROP or REJECT policy respectively. In the first
        release, the difference between "Reject" and "Drop" is that "Reject"
        REJECTs SMB traffic while "Drop" silently drops such traffic.</para>

        <para>As described above, Shorewall allows a common action for ACCEPT
        policies but does not specify such an action in the default
        configuration.</para>

        <para>For more information see the <ulink
        url="Actions.html">User-defined Action
        Page</ulink>.</para>
      </listitem>

      <listitem>
        <para>The <filename>/etc/shorewall</filename> directory no longer
        contains <filename>users</filename> file or a
        <filename>usersets</filename> file. Similar functionality is now
        available using user-defined actions.</para>

        <para>Now, action files created by copying
        <filename>/usr/share/shorewall/action.template</filename> may now
        specify a USER and or GROUP name/id in the final column just like in
        the rules file (see below). It is thus possible to create actions that
        control traffic from a list of users and/or groups.</para>
      </listitem>

      <listitem>
        <para>The last column in <filename>/etc/shorewall/rules</filename> is
        now labeled USER/GROUP and may contain:</para>

        <simplelist>
          <member>[!]&lt;<emphasis>user number</emphasis>&gt;[:]</member>

          <member>[!]&lt;<emphasis>user name</emphasis>&gt;[:]</member>

          <member>[!]:&lt;<emphasis>group number</emphasis>&gt;</member>

          <member>[!]:&lt;<emphasis>group name</emphasis>&gt;</member>

          <member>[!]&lt;<emphasis>user
          number</emphasis>&gt;:&lt;<emphasis>group
          number</emphasis>&gt;</member>

          <member>[!]&lt;<emphasis>user
          name</emphasis>&gt;:&lt;<emphasis>group
          number</emphasis>&gt;</member>

          <member>[!]&lt;<emphasis>user
          inumber</emphasis>&gt;:&lt;<emphasis>group
          name</emphasis>&gt;</member>

          <member>[!]&lt;<emphasis>user
          name</emphasis>&gt;:&lt;<emphasis>group name</emphasis>&gt;</member>
        </simplelist>
      </listitem>

      <listitem>
        <para>If your kernel has IPV6 support (recent
        <trademark>SuSe</trademark> for example), and you don't use IPV6 then
        you will probably want to set DISABLE_IPV6=Yes in <ulink
        url="Documentation.htm#Conf">/etc/shorewall/shorewall.conf</ulink>.
        You must have ipv6tables installed.</para>
      </listitem>
    </itemizedlist>
  </section>

  <section>
    <title>Version &gt;= 1.4.9</title>

    <itemizedlist>
      <listitem>
        <para>The default value of NEWNOTSYN set in <ulink
        url="Documentation.htm#Conf">/etc/shorewall/shorewall.conf</ulink> has
        been changed from 'No' to 'Yes'. I find that NEWNOTSYN=No tends to
        result in lots of "stuck" connections because any network timeout
        during TCP session tear down results in retries being dropped
        (Netfilter has removed the connection from the conntrack table but the
        end-points haven't completed shutting down the connection). I
        therefore have chosen NEWNOTSYN=Yes as the default value and I advise
        caution in using NEWNOTSYN=Yes.</para>
      </listitem>
    </itemizedlist>
  </section>

  <section>
    <title>Version &gt;= 1.4.8</title>

    <itemizedlist mark="bullet">
      <listitem>
        <para>The meaning of <varname>ROUTE_FILTER=Yes</varname> has changed.
        Previously this setting was documented as causing route filtering to
        occur on all network interfaces; this didn't work. Beginning with this
        release, <varname>ROUTE_FILTER=Yes</varname> causes route filtering to
        occur on all interfaces brought up while Shorewall is running. This
        means that it may be appropriate to set
        <varname>ROUTE_FILTER=Yes</varname> and use the routefilter option in
        <filename
        class="directory">/etc/shorewall/</filename><filename>interfaces</filename>
        entries.</para>
      </listitem>
    </itemizedlist>
  </section>

  <section>
    <title>Version &gt;= 1.4.6</title>

    <itemizedlist mark="bullet">
      <listitem>
        <para>The <varname>NAT_ENABLED</varname>,
        <varname>MANGLE_ENABLED</varname> and <varname>MULTIPORT</varname>
        options have been removed from <filename>shorewall.conf</filename>.
        These capabilities are now automatically detected by Shorewall.</para>
      </listitem>

      <listitem>
        <para>An undocumented feature previously allowed entries in the host
        file as follows: <synopsis>
zone	eth1:192.168.1.0/24,eth2:192.168.2.0/24
				</synopsis> This capability was never documented and has been removed in
        1.4.6 to allow entries of the following format: <synopsis>
zone	eth1:192.168.1.0/24,192.168.2.0/24
				</synopsis></para>
      </listitem>
    </itemizedlist>
  </section>

  <section>
    <title>Version &gt;= 1.4.4</title>

    <para>If you are upgrading from 1.4.3 and have set the
    <varname>LOGMARKER</varname> variable in <filename
    class="directory">/etc/shorewall/</filename><filename>shorewall.conf</filename>,
    then you must set the new <varname>LOGFORMAT</varname> variable
    appropriately and remove your setting of
    <varname>LOGMARKER</varname>.</para>
  </section>

  <section>
    <title>Version 1.4.4</title>

    <para>If you have zone names that are 5 characters long, you may
    experience problems starting Shorewall because the
    <option>--log-prefix</option> in a logging rule is too long. Upgrade to
    Version 1.4.4a to fix this problem.</para>
  </section>

  <section>
    <title>Version &gt;= 1.4.2</title>

    <para>There are some cases where you may want to handle traffic from a
    particular group to itself. While I personally think that such a setups
    are ridiculous, there are two cases covered in this documentation where it
    can occur: <itemizedlist>
        <listitem>
          <para><ulink url="FAQ.htm#faq2">In FAQ #2</ulink></para>
        </listitem>

        <listitem>
          <para><ulink url="Shorewall_Squid_Usage.html">When running
          <application>Squid</application> as a transparent proxy in your
          local zone.</ulink></para>
        </listitem>
      </itemizedlist> If you have either of these cases, you will want to
    review the current documentation and change your configuration
    accordingly.</para>
  </section>

  <section>
    <title>Version &gt;= 1.4.1</title>

    <itemizedlist mark="bullet">
      <listitem>
        <para>Beginning with Version 1.4.1, traffic between groups in the same
        zone is accepted by default. Previously, traffic from a zone to itself
        was treated just like any other traffic; any matching rules were
        applied followed by enforcement of the appropriate policy. With 1.4.1
        and later versions, unless you have explicit rules for traffic from Z
        to Z or you have an explicit Z to Z policy (where "Z" is some zone)
        then traffic between the groups in zone Z will be accepted. If you do
        have one or more explicit rules for Z to Z or if you have an explicit
        Z to Z policy then the behavior is as it was in prior versions.</para>

        <orderedlist numeration="arabic">
          <listitem>
            <para>If you have a Z Z ACCEPT policy for a zone to allow traffic
            between two interfaces to the same zone, that policy can be
            removed and traffic between the interfaces will traverse fewer
            rules than previously.</para>
          </listitem>

          <listitem>
            <para>If you have a Z Z DROP or Z Z REJECT policy or you have
            Z-&gt;Z rules then your configuration should not require any
            change.</para>
          </listitem>

          <listitem>
            <para>If you are currently relying on a implicit policy (one that
            has "all" in either the SOURCE or DESTINATION column) to prevent
            traffic between two interfaces to a zone Z and you have no rules
            for Z-&gt;Z then you should add an explicit DROP or REJECT policy
            for Z to Z.</para>
          </listitem>
        </orderedlist>
      </listitem>

      <listitem>
        <para>Sometimes, you want two separate zones on one interface but you
        don't want Shorewall to set up any infrastructure to handle traffic
        between them. <example>
            <title>The <filename>zones</filename>,
            <filename>interfaces</filename> and, <filename>hosts</filename>
            file contents</title>

            <programlisting>
<filename class="directory">/etc/shorewall/</filename><filename>zones</filename>
z1	Zone1	The first Zone
z2	Zone2	The second Zone

<filename class="directory">/etc/shorewall/</filename><filename>interfaces</filename>
z2	eth1	192.168.1.255

<filename class="directory">/etc/shorewall/</filename><filename>hosts</filename>
z1	eth1:192.168.1.3
					</programlisting>
          </example> Here, zone z1 is nested in zone z2 and the firewall is
        not going to be involved in any traffic between these two zones.
        Beginning with Shorewall 1.4.1, you can prevent Shorewall from setting
        up any infrastructure to handle traffic between z1 and z2 by using the
        new NONE policy: <example>
            <title>The contents of <filename>policy</filename></title>

            <programlisting>
<filename class="directory">/etc/shorewall/</filename><filename>policy</filename>
z1	z2	NONE
z2	z1	NONE
					</programlisting>
          </example> Note that NONE policies are generally used in pairs
        unless there is asymetric routing where only the traffic on one
        direction flows through the firewall and you are using a NONE polciy
        in the other direction.</para>
      </listitem>
    </itemizedlist>
  </section>

  <section>
    <title>Version 1.4.1</title>

    <itemizedlist mark="bullet">
      <listitem>
        <para>In Version 1.4.1, Shorewall will never create rules to deal with
        traffic from a given group back to itself. The
        <varname>multi</varname> interface option is no longer available so if
        you want to route traffic between two subnetworks on the same
        interface then I recommend that you upgrade to Version 1.4.2 and use
        the <varname>routeback</varname> interface or host option.</para>
      </listitem>
    </itemizedlist>
  </section>

  <section>
    <title>Version &gt;= 1.4.0</title>

    <important>
      <para>Shorewall &gt;=1.4.0 requires the <command>iproute</command>
      package ('<literal>ip</literal>' utility).</para>
    </important>

    <note>
      <para>Unfortunately, some distributions call this package
      <command>iproute2</command> which will cause the upgrade of Shorewall to
      fail with the diagnostic: <synopsis>
error: failed dependencies:iproute is needed by shorewall-1.4.0-1
				</synopsis> This may be worked around by using the
      <option>--nodeps</option> option of <command>rpm</command> (<command>rpm
      -Uvh --nodeps
      <filename>your_shorewall_rpm.rpm</filename></command>).</para>
    </note>

    <para>If you are upgrading from a version &lt; 1.4.0, then: <itemizedlist
        mark="bullet">
        <listitem>
          <para>The <varname>noping</varname> and
          <varname>forwardping</varname> interface options are no longer
          supported nor is the <varname>FORWARDPING</varname> option in
          <filename>shorewall.conf</filename>. ICMP echo-request (ping)
          packets are treated just like any other connection request and are
          subject to rules and policies.</para>
        </listitem>

        <listitem>
          <para>Interface names of the form
          <varname>&lt;device&gt;:&lt;integer&gt;</varname> in <filename
          class="directory">/etc/shorewall/</filename><filename>interfaces</filename>
          now generate a Shorewall error at startup (they always have produced
          warnings in <application
          class="software">iptables</application>).</para>
        </listitem>

        <listitem>
          <para>The <varname>MERGE_HOSTS</varname> variable has been removed
          from <filename>shorewall.conf</filename>. Shorewall 1.4 behaves like
          1.3 did when <varname>MERGE_HOSTS=Yes</varname>; that is zone
          contents are determined by <emphasis>BOTH</emphasis> the interfaces
          and hosts files when there are entries for the zone in both
          files.</para>
        </listitem>

        <listitem>
          <para>The <varname>routestopped</varname> option in the interfaces
          and hosts file has been eliminated; use entries in the
          <filename>routestopped</filename> file instead.</para>
        </listitem>

        <listitem>
          <para>The Shorewall 1.2 syntax for <varname>DNAT</varname> and
          <varname>REDIRECT</varname> rules is no longer accepted; you must
          convert to using the new syntax.</para>
        </listitem>

        <listitem>
          <para>The <varname>ALLOWRELATED</varname> variable in
          <filename>shorewall.conf</filename> is no longer supported.
          Shorewall 1.4 behavior is the same as 1.3 with
          <varname>ALLOWRELATED=Yes</varname>.</para>
        </listitem>

        <listitem>
          <para>Late-arriving DNS replies are now dropped by default; there is
          no need for your own <filename
          class="directory">/etc/shorewall/</filename><filename>common</filename>
          file simply to avoid logging these packets.</para>
        </listitem>

        <listitem>
          <para>The <filename>firewall</filename>,
          <filename>functions</filename> and <filename>version</filename>
          files have been moved to <filename
          class="directory">/usr/share/shorewall</filename>.</para>
        </listitem>

        <listitem>
          <para>The <filename>icmp.def</filename> file has been removed. If
          you include it from <filename
          class="directory">/etc/shorewall/</filename><filename>icmpdef</filename>,
          you will need to modify that file.</para>
        </listitem>

        <listitem>
          <para>If you followed the advice in FAQ #2 and call
          <varname>find_interface_address</varname> in <filename
          class="directory">/etc/shorewall/</filename><filename>params</filename>,
          that code should be moved to <filename
          class="directory">/etc/shorewall/</filename><filename>init</filename>.</para>
        </listitem>
      </itemizedlist></para>
  </section>

  <section>
    <title>Version 1.4.0</title>

    <itemizedlist mark="bullet">
      <listitem>
        <para>The <varname>multi</varname> interface option is no longer
        supported. Shorewall will generate rules for sending packets back out
        the same interface that they arrived on in two cases: <itemizedlist
            mark="hollow">
            <listitem>
              <para>There is an <emphasis>explicit</emphasis> policy for the
              source zone to or from the destination zone. An explicit policy
              names both zones and does not use the <varname>all</varname>
              reserved word.</para>
            </listitem>

            <listitem>
              <para>There are one or more rules for traffic for the source
              zone to or from the destination zone including rules that use
              the <varname>all</varname> reserved word. Exception: if the
              source zone and destination zone are the same then the rule must
              be explicit - it must name the zone in both the
              <varname>SOURCE</varname> and <varname>DESTINATION</varname>
              columns.</para>
            </listitem>
          </itemizedlist></para>
      </listitem>
    </itemizedlist>
  </section>
</article>