shorewall_code/docs/Install.xml

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<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
"http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd">
<article id="Install">
  <!--$Id$-->

  <articleinfo>
    <title>Shorewall Installation and Upgrade</title>

    <authorgroup>
      <author>
        <firstname>Tom</firstname>

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

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

    <copyright>
      <year>2001-</year>

      <year>2006</year>

      <year>2009</year>

      <year>2012</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 url="GnuCopyright.htm">GNU Free Documentation
      License</ulink></quote>.</para>
    </legalnotice>
  </articleinfo>

  <caution>
    <para><emphasis role="bold">This article applies to Shorewall 4.3 and
    later. If you are installing or upgrading to a version of Shorewall
    earlier than Shorewall 4.3.5 then please see the documentation for that
    release.</emphasis></para>
  </caution>

  <important>
    <para>Before attempting installation, I strongly urge you to read and
    print a copy of the <ulink url="shorewall_quickstart_guide.htm">Shorewall
    QuickStart</ulink> Guide for the configuration that most closely matches
    your own. This article only tells you how to install the product on your
    system. The QuickStart Guides describe how to configure the
    product.</para>
  </important>

  <important>
    <para>Before upgrading, be sure to review the <ulink
    url="upgrade_issues.htm">Upgrade Issues</ulink>.</para>
  </important>

  <note>
    <para>Shorewall RPMs are signed. To avoid warnings such as the
    following<programlisting>warning: shorewall-3.2.1-1.noarch.rpm: V3 DSA signature: NOKEY, key ID 6c562ac4</programlisting></para>

    <para>download the <ulink
    url="https://lists.shorewall.net/shorewall.gpg.key">Shorewall GPG
    key</ulink> and run this command:</para>

    <programlisting><command>rpm --import shorewall.gpg.key</command></programlisting>
  </note>

  <section id="Install_RPM">
    <title>Install using RPM</title>

    <para>To install Shorewall using the RPM:</para>

    <orderedlist>
      <listitem>
        <para><emphasis role="bold">Be sure that you have the correct RPM
        package!</emphasis></para>

        <para>The standard RPM package from shorewall.net and the mirrors is
        known to work with <emphasis
        role="bold"><trademark>SUSE</trademark></emphasis>, <emphasis
        role="bold"><trademark>Power PPC</trademark></emphasis>, <emphasis
        role="bold"><trademark>Trustix</trademark></emphasis> and <emphasis
        role="bold"><trademark>TurboLinux</trademark></emphasis>. There is
        also an RPM package provided by Simon Matter that is tailored for
        <trademark><emphasis role="bold">RedHat/Fedora</emphasis></trademark>
        and another package from Jack Coates that is customized for <emphasis
        role="bold"><trademark>Mandriva</trademark></emphasis>. All of these
        are available from the <ulink
        url="http://www.shorewall.net/download.htm">download
        page</ulink>.</para>

        <para>If you try to install the wrong package, it probably won't
        work.</para>
      </listitem>

      <listitem>
        <para>Install the RPMs</para>

        <programlisting><command>rpm -ivh &lt;shorewall rpm&gt;</command></programlisting>

        <caution>
          <para>Some users are in the habit of using the <command>rpm
          -U</command> command for installing packages as well as for updating
          them. If you use that command when installing the Shorewall RPM then
          you will have to manually enable Shorewall startup at boot time by
          running <command>chkconfig</command>, <command>insserv</command> or
          whatever utility you use to manipulate you init symbolic
          links.</para>
        </caution>

        <note>
          <para>Shorewall is dependent on the iproute package. Unfortunately,
          some distributions call this package iproute2 which will cause the
          installation of Shorewall to fail with the diagnostic:</para>

          <programlisting>error: failed dependencies:iproute is needed by shorewall-3.2.x-1</programlisting>

          <para>This problem should not occur if you are using the correct RPM
          package (see 1., above) but may be worked around by using the
          --nodeps option of rpm.</para>

          <programlisting><command>rpm -ivh --nodeps &lt;rpms&gt;</command></programlisting>
        </note>

        <para>Example:<programlisting><command>rpm -ivh shorewall-4.3.5-0base.noarch.rpm</command></programlisting></para>
      </listitem>
    </orderedlist>
  </section>

  <section id="Install_Tarball">
    <title>Install using tarball</title>

    <para>Beginning with Shorewall-4.5.0, the Shorewall packages depend on
    Shorewall-core. So the first step is to install that package:</para>

    <orderedlist>
      <listitem>
        <para>unpack the tarballs:<programlisting><command>tar -jxf shorewall-core-4.5.0.tar.bz2</command></programlisting></para>
      </listitem>

      <listitem>
        <para>cd to the shorewall directory (the version is encoded in the
        directory name as in <quote>shorewall-core-4.5.0</quote>).</para>
      </listitem>

      <listitem>
        <para>Type:</para>

        <programlisting><command>./install.sh </command></programlisting>
      </listitem>
    </orderedlist>

    <para>To install Shorewall using the tarball and install script:</para>

    <orderedlist>
      <listitem>
        <para>unpack the tarballs:<programlisting><command>tar -jxf shorewall-4.5.0.tar.bz2</command></programlisting></para>
      </listitem>

      <listitem>
        <para>cd to the shorewall directory (the version is encoded in the
        directory name as in <quote>shorewall-4.3.5</quote>).</para>
      </listitem>

      <listitem>
        <para>Type:</para>

        <programlisting><command>./install.sh </command></programlisting>

        <para>or if you are installing Shorewall or Shorewall6 version 4.4.8
        or later, you may type:</para>

        <programlisting><command>./install.sh -s</command></programlisting>

        <para>The <emphasis role="bold">-s</emphasis> option supresses
        installation of all files in <filename
        class="directory">/etc/shorewall</filename> except
        <filename>shorewall.conf</filename>. You can copy any other files you
        need from one of the <ulink url="GettingStarted.html">Samples</ulink>
        or from <filename
        class="directory">/usr/share/shorewall/configfiles/</filename>.</para>
      </listitem>

      <listitem>
        <para>If the install script was unable to configure Shorewall to be
        started automatically at boot, see <ulink
        url="starting_and_stopping_shorewall.htm">these
        instructions</ulink>.</para>
      </listitem>
    </orderedlist>

    <para>Beginning with shorewall 4.4.20.1, the installer also supports a
    <option>-a</option> (annotated) option. Beginning with that release, the
    standard configuration files (including samples) may be annotated with the
    contents of the associated manpage. The <option>-a</option> option enables
    that behavior. The default remains that the configuration files do not
    include documentation.</para>

    <section>
      <title>Executables in /usr and Perl Modules</title>

      <para>Distributions have different philosophies about the proper file
      hierarchy. Two issures are particularly contentious:</para>

      <itemizedlist>
        <listitem>
          <para>Executable files in
          <filename>/usr/share/shorewall*</filename>. These include;</para>

          <itemizedlist>
            <listitem>
              <para>getparams</para>
            </listitem>

            <listitem>
              <para>compiler.pl</para>
            </listitem>

            <listitem>
              <para>wait4ifup</para>
            </listitem>

            <listitem>
              <para>shorecap</para>
            </listitem>

            <listitem>
              <para>ifupdown</para>
            </listitem>
          </itemizedlist>
        </listitem>

        <listitem>
          <para>Perl Modules in
          <filename>/usr/share/shorewall/Shorewall</filename>.</para>
        </listitem>
      </itemizedlist>

      <para>To allow distributions to designate alternate locations for these
      files, the installers (install.sh) from 4.4.19 onward support the
      following environmental variables:</para>

      <variablelist>
        <varlistentry>
          <term>LIBEXEC</term>

          <listitem>
            <para>Determines where in /usr getparams, compiler.pl, wait4ifup,
            shorecap and ifupdown are installed. Shorewall and Shorewall6 must
            be installed with the same value of LIBEXEC. The listed
            executables are installed in
            <filename>/usr/${LIBEXEC}/shorewall*</filename>. The default value
            of LIBEXEC is 'share'. LIBEXEC is recognized by all installers and
            uninstallers.</para>

            <para>Beginning with Shorewall 4.4.20, you can specify an absolute
            path name for LIBEXEC, in which case the listed executables will
            be installed in ${LIBEXEC}/shorewall*.</para>

            <para>Beginning with Shorewall 4.5.1, you must specify an absolute
            pathname for LIBEXEC.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>PERLLIB</term>

          <listitem>
            <para>Determines where in <filename>/usr </filename>the Shorewall
            Perl modules are installed. Shorewall and Shorewall6 must be
            installed with the same value of PERLLIB. The modules are
            installed in <filename>/usr/${PERLLIB}/Shorewall</filename>. The
            default value of PERLLIB is 'share/shorewall'. PERLLIB is only
            recognized by the Shorewall and Shorewall6 installers.</para>

            <para>Beginning with Shorewall 4.4.20, you can specify an absolute
            path name for PERLLIB, in which case the Shorewall Perl modules
            will be installed in ${PERLLIB}/Shorewall/.</para>

            <para>Beginning with Shorewall 4.5.1, you must specify an absolute
            pathname for PERLLIB.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>MANDIR</term>

          <listitem>
            <para>Determines where the man pages are installed. Default is
            distribution-dependent as shown below.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </section>

    <section id="Locations">
      <title>Default Install Locations</title>

      <para>The default install locations are distribution dependent as shown
      in the following sections. These are the locations that are chosen by
      the install.sh scripts.</para>

      <section>
        <title>All Distributions</title>

        <informaltable>
          <tgroup cols="2">
            <tbody>
              <row>
                <entry><emphasis role="bold">COMPONENT</emphasis></entry>

                <entry><emphasis role="bold">LOCATION</emphasis></entry>
              </row>

              <row>
                <entry>man pages</entry>

                <entry>/usr/share/man/ (may ve overridden using
                MANDIR)</entry>
              </row>

              <row>
                <entry>Shorewall Perl Modules</entry>

                <entry>/usr/share/shorewall/ (may be overridden using
                PERLLIB)</entry>
              </row>

              <row>
                <entry>Executable helper scripts (compiler.pl, getparams,
                wait4ifup)</entry>

                <entry>/usr/share/shorewall/ (may be overridden using
                LIBEXEC)</entry>
              </row>

              <row>
                <entry>ifupdown.sh (from Shorewall-init)</entry>

                <entry>/usr/share/shorewall-init/ (may be overridden using
                LIBEXEC)</entry>
              </row>
            </tbody>
          </tgroup>
        </informaltable>
      </section>

      <section>
        <title>Debian</title>

        <informaltable>
          <tgroup cols="2">
            <tbody>
              <row>
                <entry><emphasis role="bold">COMPONENT</emphasis></entry>

                <entry><emphasis role="bold">LOCATION</emphasis></entry>
              </row>

              <row>
                <entry>CLI programs</entry>

                <entry>/sbin/<replaceable>product</replaceable></entry>
              </row>

              <row>
                <entry>Distribution-specific configuration file</entry>

                <entry>/etc/default/<replaceable>product</replaceable></entry>
              </row>

              <row>
                <entry>Init Scripts</entry>

                <entry>/etc/init.d/<replaceable>product</replaceable></entry>
              </row>

              <row>
                <entry>ifupdown scripts from Shorewall-init</entry>

                <entry>/etc/network/if-up.d/shorewall,
                /etc/network/if-post-down.d/shorewall</entry>
              </row>

              <row>
                <entry>ppp ifupdown scripts from Shorewall-init</entry>

                <entry>/etc/ppp/ip-up.d/shorewall,
                /etc/ppp/ip-down.d/shorewall /etc/ppp/ipv6-up.d/shorewall
                /etc/ppp/ipv6-down.d/shorewall</entry>
              </row>
            </tbody>
          </tgroup>
        </informaltable>
      </section>

      <section>
        <title>Redhat and Derivatives</title>

        <informaltable>
          <tgroup cols="2">
            <tbody>
              <row>
                <entry><emphasis role="bold">COMPONENT</emphasis></entry>

                <entry><emphasis role="bold">LOCATION</emphasis></entry>
              </row>

              <row>
                <entry>CLI programs</entry>

                <entry>/sbin/<replaceable>product</replaceable></entry>
              </row>

              <row>
                <entry>Distribution-specific configuration file</entry>

                <entry>/etc/sysconfig/<replaceable>product</replaceable></entry>
              </row>

              <row>
                <entry>Init Scripts</entry>

                <entry>/etc/rc.d/init.d/<replaceable>product</replaceable></entry>
              </row>

              <row>
                <entry>ifupdown scripts from Shorewall-init</entry>

                <entry>/sbin/ifup-local, /sbin/ifdown-local</entry>
              </row>

              <row>
                <entry>ppp ifupdown scripts from Shorewall-init</entry>

                <entry>/etc/ppp/ip-up.local, /etc/ppp/ip-down.local</entry>
              </row>
            </tbody>
          </tgroup>
        </informaltable>
      </section>

      <section>
        <title>SuSE</title>

        <informaltable>
          <tgroup cols="2">
            <tbody>
              <row>
                <entry><emphasis role="bold">COMPONENT</emphasis></entry>

                <entry><emphasis role="bold">LOCATION</emphasis></entry>
              </row>

              <row>
                <entry>CLI programs</entry>

                <entry>/sbin/<replaceable>product</replaceable></entry>
              </row>

              <row>
                <entry>Distribution-specific configuration file</entry>

                <entry>/etc/sysconfig/<replaceable>product</replaceable></entry>
              </row>

              <row>
                <entry>Init Scripts</entry>

                <entry>/etc/init.d/<replaceable>product</replaceable></entry>
              </row>

              <row>
                <entry>ifupdown scripts from Shorewall-init</entry>

                <entry>/etc/sysconfig/network/if-up.d/shorewall,
                /etc/sysconfig/network/if-down.d/shorewall</entry>
              </row>

              <row>
                <entry>ppp ifupdown scripts from Shorewall-init</entry>

                <entry>/etc/ppp/ip-up.d/shorewall,
                /etc/ppp/ip-down.d/shorewall /etc/ppp/ipv6-up.d/shorewall
                /etc/ppp/ipv6-down.d/shorewall</entry>
              </row>
            </tbody>
          </tgroup>
        </informaltable>
      </section>

      <section>
        <title>Cygwin</title>

        <informaltable>
          <tgroup cols="2">
            <tbody>
              <row>
                <entry><emphasis role="bold">COMPONENT</emphasis></entry>

                <entry><emphasis role="bold">LOCATION</emphasis></entry>
              </row>

              <row>
                <entry>CLI programs</entry>

                <entry>/bin/<replaceable>product</replaceable></entry>
              </row>

              <row>
                <entry>Distribution-specific configuration file</entry>

                <entry>N/A</entry>
              </row>

              <row>
                <entry>Init Scripts</entry>

                <entry>N/A</entry>
              </row>

              <row>
                <entry>ifupdown scripts from Shorewall-init</entry>

                <entry>N/A</entry>
              </row>

              <row>
                <entry>ppp ifupdown scripts from Shorewall-init</entry>

                <entry>N/A</entry>
              </row>
            </tbody>
          </tgroup>
        </informaltable>
      </section>

      <section>
        <title>OS X</title>

        <informaltable>
          <tgroup cols="2">
            <tbody>
              <row>
                <entry><emphasis role="bold">COMPONENT</emphasis></entry>

                <entry><emphasis role="bold">LOCATION</emphasis></entry>
              </row>

              <row>
                <entry>CLI programs</entry>

                <entry>/sbin/<replaceable>product</replaceable></entry>
              </row>

              <row>
                <entry>Distribution-specific configuration file</entry>

                <entry>N/A</entry>
              </row>

              <row>
                <entry>Init Scripts</entry>

                <entry>N/A</entry>
              </row>

              <row>
                <entry>ifupdown scripts from Shorewall-init</entry>

                <entry>N/A</entry>
              </row>

              <row>
                <entry>ppp ifupdown scripts from Shorewall-init</entry>

                <entry>N/A</entry>
              </row>
            </tbody>
          </tgroup>
        </informaltable>
      </section>
    </section>
  </section>

  <section id="Debian">
    <title>Install the .deb</title>

    <important>
      <para>Once you have installed the .deb packages and before you attempt
      to configure Shorewall, please heed the advice of Lorenzo Martignoni,
      former Shorewall Debian Maintainer:</para>

      <para><quote>For more information about Shorewall usage on Debian system
      please look at /usr/share/doc/shorewall-common/README.Debian provided by
      [the] shorewall Debian package.</quote></para>
    </important>

    <para>The easiest way to install Shorewall on Debian, is to use
    apt-get<command>.</command></para>

    <para>First, to ensure that you are installing the latest version of
    Shorewall, please modify your
    <filename>/etc/apt/preferences:</filename></para>

    <para><programlisting>Package: shorewall
Pin: release o=Debian,a=testing
Pin-Priority: 700

Package: shorewall-doc
Pin: release o=Debian,a=testing
Pin-Priority: 700</programlisting><emphasis role="bold"><emphasis>Then
    run:</emphasis></emphasis><programlisting># apt-get update
# apt-get install shorewall</programlisting></para>

    <para><emphasis><emphasis role="bold">Once you have completed configuring
    Shorewall, you can enable startup at boot time by setting startup=1 in
    <filename>/etc/default/shorewall</filename>.</emphasis></emphasis></para>
  </section>

  <section id="Upgrade">
    <title>General Notes about Upgrading Shorewall</title>

    <para>Most problems associated with upgrades come from two causes:</para>

    <itemizedlist>
      <listitem>
        <para>The user didn't read and follow the migration considerations in
        the release notes (these are also reproduced in the <ulink
        url="upgrade_issues.htm">Shorewall Upgrade Issues</ulink>).</para>
      </listitem>

      <listitem>
        <para>The user mis-handled the
        <filename>/etc/shorewall/shorewall.conf</filename> file during
        upgrade. Shorewall is designed to allow the default behavior of the
        product to evolve over time. To make this possible, the design assumes
        that <emphasis role="bold">you will not replace your current
        shorewall.conf</emphasis> <emphasis role="bold">file during
        upgrades</emphasis>. It is recommended that after you first install
        Shorewall that you modify
        <filename>/etc/shorewall/shorewall.conf</filename> so as to prevent
        your package manager from overwriting it during subsequent upgrades
        (since the addition of STARTUP_ENABLED, such modification is assured
        since you must manually change the setting of that option). If you
        feel absolutely compelled to have the latest options in your
        shorewall.conf then you must proceed carefully. You should determine
        which new options have been added and you must reset their value (e.g.
        OPTION=""); otherwise, you will get different behavior from what you
        expect.</para>
      </listitem>
    </itemizedlist>
  </section>

  <section id="Upgrade_RPM">
    <title>Upgrade using RPM</title>

    <para>If you already have the Shorewall RPM installed and are upgrading to
    a new version:</para>

    <orderedlist>
      <listitem>
        <para><emphasis role="bold">Be sure that you have the correct RPM
        package!</emphasis></para>

        <para>The standard RPM package from shorewall.net and the mirrors is
        known to work with <trademark>SUSE</trademark>, Power PPC, Trustix and
        TurboLinux. There is also an RPM package provided by Simon Matter that
        is tailored for RedHat/Fedora and another package from Jack Coates
        that is customized for Mandriva. If you try to upgrade using the wrong
        package, it probably won't work.<important>
            <para>Simon Matter names his '<emphasis>common</emphasis>' rpm
            '<emphasis>shorewall</emphasis>' rather than
            '<emphasis>shorewall-common</emphasis>'.</para>
          </important></para>
      </listitem>

      <listitem>
        <para>If you are upgrading from a 2.x or 3.x version to a 4.x version
        or later, please see the <ulink url="upgrade_issues.htm">upgrade
        issues</ulink> for specific instructions.</para>
      </listitem>

      <listitem>
        <para>Upgrade the RPM</para>

        <programlisting><command>rpm -Uvh &lt;shorewall rpm file&gt; </command></programlisting>

        <note>
          <para>Shorewall is dependent on the iproute package. Unfortunately,
          some distributions call this package iproute2 which will cause the
          upgrade of Shorewall to fail with the diagnostic:</para>

          <programlisting>error: failed dependencies:iproute is needed by shorewall-3.2.1-1</programlisting>

          <para>This may be worked around by using the --nodeps option of
          rpm.</para>

          <programlisting><command>rpm -Uvh --nodeps &lt;shorewall rpm&gt; ...</command></programlisting>
        </note>
      </listitem>

      <listitem>
        <para>See if there are any incompatibilities between your
        configuration and the new Shorewall version and correct as
        necessary.</para>

        <programlisting><command>shorewall check</command></programlisting>
      </listitem>

      <listitem>
        <para>Restart the firewall.</para>

        <programlisting><command>shorewall restart</command></programlisting>
      </listitem>
    </orderedlist>
  </section>

  <section id="Upgrade_Tarball">
    <title>Upgrade using tarball</title>

    <para><important>
        <para>If you are upgrading from a 2.x or 3.x version to a 4.x version
        or later, please see the <ulink url="upgrade_issues.htm">upgrade
        issues</ulink> for specific instructions.</para>
      </important></para>

    <para>If you are upgrading to version 4.5.0 or later, you must first
    install or upgrade the Shorewall-core package:</para>

    <orderedlist>
      <listitem>
        <para>unpack the tarballs:<programlisting><command>tar -jxf shorewall-core-4.5.0.tar.bz2</command></programlisting></para>
      </listitem>

      <listitem>
        <para>cd to the shorewall directory (the version is encoded in the
        directory name as in <quote>shorewall-core-4.5.0</quote>).</para>
      </listitem>

      <listitem>
        <para>Type:</para>

        <programlisting><command>./install.sh </command></programlisting>
      </listitem>
    </orderedlist>

    <para>If you already have Shorewall installed and are upgrading to a new
    version using the tarball:</para>

    <orderedlist>
      <listitem>
        <para>unpack the tarball:<programlisting><command>tar -jxf shorewall-4.5.0.tar.bz2</command></programlisting></para>
      </listitem>

      <listitem>
        <para>cd to the shorewall-perl directory (the version is encoded in
        the directory name as in <quote>shorewall-4.5.0</quote>).</para>
      </listitem>

      <listitem>
        <para>Type:</para>

        <programlisting><command>./install.sh</command></programlisting>

        <para>or if you are installing Shorewall or Shorewall6 version 4.4.8
        or later, you may type:</para>

        <programlisting><command>./install.sh -s</command></programlisting>

        <para>The <emphasis role="bold">-s</emphasis> option supresses
        installation of all files in <filename
        class="directory">/etc/shorewall</filename> except
        <filename>shorewall.conf</filename>. You can copy any other files you
        need from one of the <ulink url="GettingStarted.html">Samples</ulink>
        or from <filename
        class="directory">/usr/share/shorewall/configfiles/</filename>.</para>
      </listitem>

      <listitem>
        <para>See if there are any incompatibilities between your
        configuration and the new Shorewall version and correct as
        necessary.</para>

        <programlisting><command>shorewall check</command></programlisting>
      </listitem>

      <listitem>
        <para>Start the firewall by typing</para>

        <programlisting><command>shorewall start</command></programlisting>
      </listitem>

      <listitem>
        <para>If the install script was unable to configure Shorewall to be
        started automatically at boot, see <ulink
        url="starting_and_stopping_shorewall.htm">these
        instructions</ulink>.</para>
      </listitem>
    </orderedlist>
  </section>

  <section id="Upgrade_Deb">
    <title>Upgrading the .deb</title>

    <warning>
      <para>When the installer asks if you want to replace
      /etc/shorewall/shorewall.conf with the new version, we strongly advise
      you to say No. See <link linkend="Upgrade">above</link>.</para>
    </warning>
  </section>

  <section id="Config_Files">
    <title>Configuring Shorewall</title>

    <para>You will need to edit some or all of the configuration files to
    match your setup. In most cases, the <ulink
    url="shorewall_quickstart_guide.htm">Shorewall QuickStart Guides</ulink>
    contain all of the information you need.</para>
  </section>

  <section id="Uninstall">
    <title>Uninstall/Fallback</title>

    <para>See <quote><ulink url="fallback.htm">Fallback and
    Uninstall</ulink></quote>.</para>
  </section>
</article>