forked from extern/shorewall_code
945 lines
34 KiB
XML
945 lines
34 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
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"http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd">
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<article>
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<!--$Id$-->
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<articleinfo>
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<title>Issues when Upgrading to Shorewall 4.4 (Upgrading from Debian Lenny
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to Squeeze)</title>
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<authorgroup>
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<author>
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<firstname>Tom</firstname>
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<surname>Eastep</surname>
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</author>
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</authorgroup>
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<pubdate><?dbtimestamp format="Y/m/d"?></pubdate>
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<copyright>
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<year>2009</year>
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<holder>Thomas M. Eastep</holder>
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</copyright>
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<legalnotice>
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<para>Permission is granted to copy, distribute and/or modify this
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document under the terms of the GNU Free Documentation License, Version
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1.2 or any later version published by the Free Software Foundation; with
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no Invariant Sections, with no Front-Cover, and with no Back-Cover
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Texts. A copy of the license is included in the section entitled
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<quote><ulink url="GnuCopyright.htm">GNU Free Documentation
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License</ulink></quote>.</para>
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</legalnotice>
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</articleinfo>
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<section>
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<title>Introduction</title>
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<para>Debian Lenny includes Shorewall version 4.0.15 while Squeeze will
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soon include Shorewall 4.4. Because there are significant differences
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between the two product versions, some users may experience upgrade
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issues. This article outlines those issues and offers advice for dealing
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with them.</para>
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<note>
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<para>Although this article is targeted specifically at Lenny ->
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Squeeze upgrades, it should be useful to any Shorewall-shell user
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upgrading to Shorewall 4.4.x. Footnotes are used to flag areas where
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non-Debian users may experience different results.</para>
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</note>
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</section>
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<section id="Packages">
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<title>Packaging Differences</title>
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<para>The first key difference between Shorewall 4.0 and Shorewall 4.4 is
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in the packaging<footnote>
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<para>Most distributions use a similar packaging structure. Note,
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however, that the 'shorewall' package in Simon Mater's RPMs for
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RedHat/Fedora/CentOS is like the Lenny shorewall-common
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package.</para>
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</footnote>. In Lenny, there are six Shorewall packages:</para>
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<orderedlist>
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<listitem>
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<para>shorewall-common — Contains the basic components needed to
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create an IPv4 firewall.</para>
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</listitem>
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<listitem>
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<para>shorewall-shell — The legacy Shorewall configuration compiler
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written in Bourne shell.</para>
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</listitem>
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<listitem>
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<para>shorewall — A transitional package that depends on
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shorewall-common and shorewall-shell. Installing this package installs
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both shorewall-common and shorewall-shell.</para>
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</listitem>
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<listitem>
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<para>shorewall-perl — A re-implementation of the Shorewall
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configuration compiler in Perl. This compiler has many advantages over
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the shell-based compiler:</para>
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<itemizedlist>
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<listitem>
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<para>The compiler is much faster</para>
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</listitem>
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<listitem>
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<para>The compiler does a much better job of validating the
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configuration, thus avoiding run-time errors.</para>
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</listitem>
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<listitem>
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<para>The compiler produces better and more consistent diagnostic
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messages.</para>
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</listitem>
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<listitem>
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<para>The compiler produces a script that runs much faster and
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that does not reject/drop connections during start/restart.</para>
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</listitem>
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</itemizedlist>
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</listitem>
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<listitem>
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<para>shorewall-lite — A small package that can run scripts generated
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by shorewall-shell or shorewall-perl. Allows centralized firewall
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administration.</para>
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</listitem>
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<listitem>
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<para>shorewall-doc — Documentation.</para>
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</listitem>
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</orderedlist>
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<para>In Squeeze, there are five packages:</para>
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<orderedlist>
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<listitem>
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<para>shorewall — Contains everything needed to create an IPv4
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firewall. It combines the former shorewall-common and shorewall-perl
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packages.</para>
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</listitem>
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<listitem>
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<para>shorewall6 — Depends on shorewall. Adds those components needed
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to create an IPv6 firewall.</para>
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</listitem>
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<listitem>
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<para>shorewall-lite — Same as in Lenny; only runs IPv4 firewall
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scripts.</para>
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</listitem>
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<listitem>
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<para>shorewall6-lite — Similar to shorewall-lite, except that it only
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runs IPv6 firewall scripts.</para>
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</listitem>
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<listitem>
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<para>shorewall-doc — Documentation.</para>
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</listitem>
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</orderedlist>
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<warning>
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<para>Do not purge the old packages (shorewall-common, shorewall-shell
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and shorewall-perl) until after the new shorewall package has been
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installed.</para>
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</warning>
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<para>The key change in Squeeze that may produce upgrade issues is that
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Squeeze does not include the shell-based configuration compiler. As a
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consequence, unless you are already using Shorewall-perl on Lenny, an
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upgrade from Lenny to Squeeze will mean that you will be switching from
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the old shell-based compiler to the new Perl-based compiler<footnote>
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<para>Note that Perl is a required package on Debian. If you are
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running an embedded distribution which does not include Perl and it is
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not feasible to install Perl on your firewall, then you should
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consider installing Shorewall on another system in your network (may
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be a <trademark>Windows</trademark> system running
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<trademark>Cygwin</trademark>) and installing Shorewall-lite on your
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firewall.</para>
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</footnote>. While the two compilers are highly compatible, there are
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some differences. Those differences are detailed in the following
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sections.</para>
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</section>
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<section id="Issues">
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<title>Issues Most Likely to Cause Problems or Concerns</title>
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<section id="conf">
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<title>shorewall.conf</title>
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<para>As always, when upgrading from one major release of Shorewall to
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another, the installer will prompt you about replacing your existing
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<filename>shorewall.conf</filename> with the updated one from the
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package. Shorewall is designed with the assumption that users will never
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replace shorewall.conf and retaining your existing file will always
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produce upward-compatible behavior.</para>
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<para>That having been said, there are a few settings that you may have
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in your shorewall.conf that will cause compilation warning or error
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messages after the upgrade.</para>
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<variablelist>
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<varlistentry>
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<term>BLACKLISTNEWONLY</term>
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<listitem>
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<para>If you have BLACKLISTNEWONLY=No together with
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FASTACCEPT=Yes, you will receive this error:</para>
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<para><emphasis role="bold">ERROR: BLACKLISTNEWONLY=No may not be
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specified with FASTACCEPT=Yes</emphasis></para>
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<para>To eliminate the error, reverse the setting of one of the
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options.</para>
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<note>
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<para>This combination never worked correctly in earlier
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versions -- to duplicate the earlier behavior, you will want to
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set BLACKLISTNEWONLY=Yes.</para>
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</note>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>BRIDGING</term>
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<listitem>
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<para>If you have set this option to Yes, you will receive the
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following error:</para>
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<para><emphasis role="bold">ERROR: BRIDGING=Yes is not supported
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by Shorewall 4.4.x</emphasis></para>
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<para>You should not be receiving this error if you are upgrading
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from Lenny since BRIDGING=Yes did not work in that
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release<footnote>
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<para>If you are upgrading from a release using a kernel
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earlier than 2.6.20, then BRIDGING=Yes did work correctly with
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Shorewall-shell.</para>
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</footnote>. If you have a bridge configuration where you want
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to control connections through the bridge, you will want to visit
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<ulink
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url="http://www.shorewall.net/bridge-Shorewall-perl.html">http://www.shorewall.net/bridge-Shorewall-perl.html</ulink><footnote>
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<para>Kernel 2.6.20 or later is required.</para>
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</footnote>.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>DELAYBLACKLISTLOAD</term>
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<listitem>
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<para>If you have set this option to Yes, you will receive the
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following warning:</para>
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<para><emphasis role="bold">WARNING: DELAYBLACKLIST=Yes is not
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supported by Shorewall 4.4.x</emphasis></para>
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<para>To eliminate the warning, set DELAYBLACKLISTLOAD=No or
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remove the setting altogether.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>DYNAMIC_ZONES</term>
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<listitem>
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<para>If you have set this option to Yes, you will receive the
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following warning:</para>
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<para><emphasis role="bold">WARNING: DYNAMIC_ZONES=Yes is not
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supported by Shorewall 4.4.x</emphasis></para>
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<para>To eliminate the warning, set DYNAMIC_ZONES=No or remove the
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setting altogether. See <ulink url="Dynamic.html">this
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article</ulink> to learn how to set up Dynamic Zones under
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Shorewall 4.4.</para>
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</listitem>
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</varlistentry>
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<varlistentry id="FW">
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<term>FW</term>
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<listitem>
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<para>If a setting for FW appears in your shorewall.conf file, you
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will receive this warning:</para>
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<para><emphasis role="bold">WARNING: Unknown configuration option
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(FW) ignored.</emphasis></para>
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<para>Remove the setting from the file and modify your
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<filename>/etc/shorewall/zones</filename> file as described <link
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linkend="zones">below</link>.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>IPSECFILE</term>
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<listitem>
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<para>If you have specified IPSECFILE=ipsec or IPSECFILE= or if
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you do not have a setting for IPSECFILE, then you will receive the
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following error:</para>
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<para><emphasis role="bold">ERROR: IPSECFILE=ipsec is not
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supported by Shorewall 4.4.x</emphasis></para>
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<para>To eliminate the warning, you will need to:</para>
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<orderedlist>
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<listitem>
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<para>Set IPSECFILE=zones</para>
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</listitem>
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<listitem>
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<para>Modify your <filename>/etc/shorewall/zones</filename>
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file as described <link linkend="zones">below</link>.</para>
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</listitem>
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</orderedlist>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>PKTTYPE</term>
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<listitem>
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<para>The PKTTYPE option is ignored by Shorewall-perl.
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Shorewall-perl will use Address type match if it is available;
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otherwise, it will behave as if PKTTYPE=No had been
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specified.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>RFC1918_LOG_LEVEL</term>
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<listitem>
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<para>If you have specified any setting for this option, you will
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receive the following warning:</para>
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<para><emphasis role="bold">WARNING: RFC1918_LOG_LEVEL=value
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ignored. The 'norfc1918' interface/host option is no longer
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supported.</emphasis></para>
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<para>To eliminate the warning, set RFC1918_LOG_LEVEL= or simply
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remove the setting altogether.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>RFC1918_STRICT</term>
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<listitem>
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<para>If you have set this option to Yes, you will receive the
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following warning:</para>
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<para><emphasis role="bold">WARNING: RFC1918_STRICT=Yes is not
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supported by Shorewall 4.4.x</emphasis></para>
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<para>To eliminate the warning, set RFC1918_STRICT=No or remove
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the setting altogether.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>SAVE_IPSETS</term>
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<listitem>
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<para>Shorewall 4.4.0-4.4.5 will issue a warning if you set
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SAVE_IPSETS=Yes in <filename>shorewall.conf</filename>:</para>
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<para><emphasis role="bold">WARNING SAVE_IPSETS=Yes is not
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supported by Shorewall 4.4.x</emphasis></para>
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<para>To eliminate this message, you will need to set
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SAVE_IPSETS=No or remove the setting altogether.</para>
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<para>See <link linkend="ipsets">below</link> for additional
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information regarding ipsets in Shorewall 4.4.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>SHOREWALL_COMPILER</term>
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<listitem>
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<para>If you have specified SHOREWALL_COMPILER=shell, you will
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receive the following warning message:</para>
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<para><emphasis role="bold">WARNING: SHOREWALL_COMPILER=shell
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ignored. Shorewall-shell support has been removed in this
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release</emphasis></para>
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<para>To eliminate the warning, set SHOREWALL_COMPILER=perl or
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simply remove the setting altogether.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>USE_ACTIONS</term>
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<listitem>
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<para>If you have set this option to No, you will receive the
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following warning:</para>
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<para><emphasis role="bold">WARNING: USE_ACTIONS=No is not
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supported by Shorewall 4.4.x</emphasis></para>
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<para>To eliminate the warning, set USE_ACTIONS=Yes or remove the
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setting altogether.</para>
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</listitem>
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</varlistentry>
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</variablelist>
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</section>
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<section id="zones">
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<title>/etc/shorewall/zones</title>
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<para>If the column headings in your /etc/shorewall/zones file look like
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this:</para>
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<programlisting>#ZONE DISPLAY COMMENTS
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net Net The big bad net
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loc Local The local LAN</programlisting>
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<para>then you are using the original zones file format that has been
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deprecated since Shorewall 3.0.</para>
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<para>You will need to convert to the new file format which has the
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following headings:</para>
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<programlisting>#ZONE TYPE OPTIONS IN OUT
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# OPTIONS OPTIONS</programlisting>
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<para>You will need to add an entry for your firewall zone. The default
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name for the firewall zone is 'fw' but may have been overriden using
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<link linkend="FW">the FW option in
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<filename>shorewall.conf</filename></link>.</para>
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<programlisting>#ZONE TYPE OPTIONS IN OUT
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# OPTIONS OPTIONS
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fw firewall</programlisting>
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<para>The remainder of your zones will have type 'ipv4' unless they are
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mentioned in your /etc/shorewall/ipsec file (see <link
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linkend="ipsec">below</link>).</para>
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<programlisting>#ZONE TYPE OPTIONS IN OUT
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# OPTIONS OPTIONS
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fw firewall
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net ipv4 # The big bad net
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loc ipv4 # The local LAN</programlisting>
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</section>
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<section id="ipsec">
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<title>/etc/shorewall/ipsec</title>
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<para>This file is no longer used -- its specifications are now included
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in <filename>/etc/shorewall/zones</filename>.</para>
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<para>Take this example:</para>
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<programlisting>#ZONE IPSEC OPTIONS IN OUT
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# ONLY OPTIONS OPTIONS
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ipsec1 Yes
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ipsec2 No</programlisting>
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<para>This would translate to the following entries in
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<filename>/etc/shorewall/zones</filename>:</para>
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<programlisting>#ZONE TYPE OPTIONS IN OUT
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# OPTIONS OPTIONS
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ipsec1 ipsec4
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ipsec2 ipv4</programlisting>
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<para>Any OPTIONS, IN OPTIONS and OUT OPTIONS should simply be copied
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from <filename>/etc/shorewall/ipsec</filename> to
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<filename>/etc/shorewall/zones</filename>.</para>
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</section>
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|
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<section id="interfaces">
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<title>/etc/shorewall/interfaces</title>
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|
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<para>The BROADCAST column is essentially unused in Squeeze. If it
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contains anything except 'detect' or '-', then you will receive this
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warning<footnote>
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|
<para>Users whose kernel and/or iptables do not include Address Type
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Match Support can continue to list broadcast addresses in this
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column; no warning will be issued.</para>
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</footnote>:</para>
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|
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<blockquote>
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<para><emphasis role="bold">WARNING: Shorewall no longer uses
|
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broadcast addresses in rule generation when Address Type Match is
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available</emphasis></para>
|
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</blockquote>
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|
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<para>To eliminate the warning, replace the contents of the BROADCAST
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column with '-' or 'detect'.</para>
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|
|
<para>The 'norfc1918' option has been removed. If you specify the
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option, you will receive the following warning:</para>
|
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|
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<blockquote>
|
|
<para><emphasis role="bold">WARNING: Support for the norfc1918
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interface option has been removed from Shorewall</emphasis></para>
|
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</blockquote>
|
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|
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<para>To eliminate the warning, simply remove the 'norfc1918' option
|
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from the OPTIONS list. You may wish to consider NULL_ROUTE_RFC1918=Yes
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as a replacement (see <ulink
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url="manpages/shorewall.conf.html">shorewall.conf</ulink> (5)).</para>
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</section>
|
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|
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<section id="hosts">
|
|
<title>/etc/shorewall/hosts</title>
|
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|
|
<para>The 'norfc1918' option has been removed. If you specify the
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option, you will receive the following warning:</para>
|
|
|
|
<blockquote>
|
|
<para><emphasis role="bold">WARNING: The 'norfc1918' option is no
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longer supported</emphasis></para>
|
|
</blockquote>
|
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|
|
<para>To eliminate the warning, simply remove the 'norfc1918' option
|
|
from the OPTIONS list. You may wish to consider NULL_ROUTE_RFC1918=Yes
|
|
as a replacement (see <ulink
|
|
url="manpages/shorewall.conf.html">shorewall.conf</ulink> (5)).</para>
|
|
</section>
|
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|
|
<section id="policy">
|
|
<title>/etc/shorewall/policy</title>
|
|
|
|
<para>Shorewall 4.4 detects dead policy file entries that result when an
|
|
entry is masked by an earlier more general entry.</para>
|
|
|
|
<para>Example:</para>
|
|
|
|
<programlisting>#SOURCE DEST POLICY LOG LEVEL
|
|
all all REJECT info
|
|
loc net ACCEPT</programlisting>
|
|
|
|
<para>Shorewall-shell silently accepted the above even though the
|
|
loc->net policy is useless. Shorewall-perl generates a fatal
|
|
compilation error:</para>
|
|
|
|
<blockquote>
|
|
<para><emphasis role="bold">ERROR: Policy "loc net ACCEPT" duplicates
|
|
earlier policy "all all REJECT"</emphasis></para>
|
|
</blockquote>
|
|
</section>
|
|
|
|
<section id="masq">
|
|
<title>/etc/shorewall/masq</title>
|
|
|
|
<para>There is a long tradition of specifying an interface name in the
|
|
SOURCE column of this file.</para>
|
|
|
|
<para>Masquerading/SNAT occurs in the Netfilter POSTROUTING chain where
|
|
an incoming interface may not be specified in iptables rules.
|
|
Consequently, while processing the <command>shorewall start</command>
|
|
and <command>shorewall restart</command> commands, the generated script
|
|
must examine the firewall's main routing table to determine those
|
|
networks that are routed out of the interface; the script then adds a
|
|
MASQUERADE/SNAT rule for connections from each of those networks. This
|
|
additional processing requires the named interface to be up and
|
|
configured when Shorewall starts or restarts.</para>
|
|
|
|
<para>Users often complain that Shorewall fails to start at boot time
|
|
because a VPN interface that is named as a masq SOURCE isn't up and
|
|
configured during boot.</para>
|
|
|
|
<para>To emphasize this restriction, if an interface is named in the
|
|
SOURCE column of one or more entries, a single warning is issued as
|
|
follows:</para>
|
|
|
|
<blockquote>
|
|
<para><emphasis role="bold">WARNING: Using an interface as the masq
|
|
SOURCE requires the interface to be up and configured when Shorewall
|
|
starts/restarts</emphasis></para>
|
|
</blockquote>
|
|
|
|
<para>To suppress this warning, replace the interface name with the list
|
|
of networks that are routed out of the interface.</para>
|
|
|
|
<para>Example.</para>
|
|
|
|
<para>Existing entry:</para>
|
|
|
|
<programlisting>#INTERFACE SOURCE ADDRESS PROTO PORT(S) IPSEC MARK USER/
|
|
# GROUP
|
|
eth0 eth1</programlisting>
|
|
|
|
<para>Current routing configuration:</para>
|
|
|
|
<programlisting>gateway:~# ip route ls dev eth1
|
|
<emphasis role="bold">172.20.1.0/24</emphasis> proto kernel scope link src 172.20.1.254
|
|
224.0.0.0/4 scope link
|
|
gateway:~#
|
|
</programlisting>
|
|
|
|
<para>Replacement entry:</para>
|
|
|
|
<programlisting>#INTERFACE SOURCE ADDRESS PROTO PORT(S) IPSEC MARK USER/
|
|
# GROUP
|
|
eth0 <emphasis role="bold">172.20.1.0/24</emphasis></programlisting>
|
|
|
|
<para>Note that no entry is included for 224.0.0.0/4 since that is the
|
|
multicast IP range and there should never be any packets with a SOURCE
|
|
IP address in that network.</para>
|
|
</section>
|
|
|
|
<section id="rules">
|
|
<title>/etc/shorewall/rules</title>
|
|
|
|
<para>If you include a destination zone in a 'nonat' rule, Shorewall
|
|
issues the following warning:</para>
|
|
|
|
<blockquote>
|
|
<para><emphasis role="bold">WARNING: Destination zone (zonename)
|
|
ignored.</emphasis></para>
|
|
</blockquote>
|
|
|
|
<para>Nonat rules include:</para>
|
|
|
|
<blockquote>
|
|
<simplelist>
|
|
<member>DNAT-</member>
|
|
|
|
<member>REDIRECT-</member>
|
|
|
|
<member>NONAT</member>
|
|
</simplelist>
|
|
</blockquote>
|
|
|
|
<para>To eliminate the warning, remove the DEST zone.</para>
|
|
|
|
<para>Example.</para>
|
|
|
|
<para>Before:</para>
|
|
|
|
<programlisting>#ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL RATE USER/ MARK CONNLIMIT TIME
|
|
# PORT PORT(S) DEST LIMIT GROUP
|
|
NONAT loc net tcp 80</programlisting>
|
|
|
|
<para>After:</para>
|
|
|
|
<programlisting>#ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL RATE USER/ MARK CONNLIMIT TIME
|
|
# PORT PORT(S) DEST LIMIT GROUP
|
|
NONAT loc - tcp 80</programlisting>
|
|
</section>
|
|
|
|
<section id="routestopped">
|
|
<title>/etc/shorewall/routestopped</title>
|
|
|
|
<para>The 'critical' option is no longer needed and hence is no longer
|
|
supported. If you have critical hosts defined, you will receive this
|
|
warning:</para>
|
|
|
|
<blockquote>
|
|
<para><emphasis role="bold">WARNING: The 'critical' option is no
|
|
longer supported (or needed)</emphasis></para>
|
|
</blockquote>
|
|
|
|
<para>To suppress the warning, simply remove the option.</para>
|
|
|
|
<para>Shorewall 4.4 also treats the <filename>routestopped</filename>
|
|
file differently from earlier releases. Previously, the
|
|
<filename>routestopped</filename> file was parsed during
|
|
<command>shorewall stop</command> processing so that changes made to the
|
|
file while Shorewall was running would be applied at the next
|
|
<command>stop</command>. This is no longer the case -- the
|
|
<filename>routestopped</filename> file is processed during compilation
|
|
just like the rest of the configuration files so that when
|
|
<command>shorewall stop</command> is issued, the firewall will pass
|
|
traffic based on the contents of the <filename>routestopped</filename>
|
|
file at the last <command>start</command> or
|
|
<command>restart</command>.</para>
|
|
|
|
<para>If you change the <filename>routestopped</filename> file and now
|
|
want to stop the firewall, you can run this sequence of commands:</para>
|
|
|
|
<programlisting><command>shorewall compile
|
|
shorewall stop</command></programlisting>
|
|
</section>
|
|
|
|
<section id="tos">
|
|
<title>/etc/shorewall/tos</title>
|
|
|
|
<para>The <filename>/etc/shorewall/tos</filename> file now has
|
|
zone-independent SOURCE and DEST columns as do all other files except
|
|
the rules and policy files.</para>
|
|
|
|
<para>The SOURCE column may be one of the following:</para>
|
|
|
|
<simplelist>
|
|
<member>[<command>all</command>:]<<replaceable>address</replaceable>>[,...]</member>
|
|
|
|
<member>[<command>all</command>:]<<replaceable>interface</replaceable>>[:<<replaceable>address</replaceable>>[,...]]</member>
|
|
|
|
<member><command>$FW</command>[:<<replaceable>address</replaceable>>[,...]]</member>
|
|
</simplelist>
|
|
|
|
<para>The DEST column may be one of the following:</para>
|
|
|
|
<simplelist>
|
|
<member>[<command>all</command>:]<<replaceable>address</replaceable>>[,...]</member>
|
|
|
|
<member>[<command>all</command>:]<<replaceable>interface</replaceable>>[:<<replaceable>address</replaceable>>[,...]]</member>
|
|
</simplelist>
|
|
|
|
<para>This is a permanent change. The old zone-based rules have never
|
|
worked right and this is a good time to replace them. We have tried to
|
|
make the new syntax cover the most common cases without requiring change
|
|
to existing files. In particular, it will handle the
|
|
<filename>tos</filename> file released with Shorewall 1.4 and
|
|
earlier.</para>
|
|
</section>
|
|
|
|
<section id="extension">
|
|
<title>Extension Scripts</title>
|
|
|
|
<para>With the shell-based compiler, all extension scripts were copied
|
|
into the compiled script and executed at run-time. In some cases, this
|
|
approach doesn't work with Shorewall Perl because (almost) the entire
|
|
rule set is built by the compiler. As a result, Shorewall-perl runs some
|
|
extension scripts at compile-time rather than at run-time. Because the
|
|
compiler is written in Perl, these extension scripts from earlier
|
|
versions will no longer work.</para>
|
|
|
|
<para>The following table summarizes when the various extension scripts
|
|
are run:<informaltable align="left" frame="none">
|
|
<tgroup cols="3">
|
|
<tbody>
|
|
<row>
|
|
<entry><emphasis role="bold">Compile-time (Must be written in
|
|
Perl)</emphasis></entry>
|
|
|
|
<entry><emphasis role="bold">Run-time</emphasis></entry>
|
|
|
|
<entry><emphasis role="bold">Eliminated</emphasis></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry>initdone</entry>
|
|
|
|
<entry>clear</entry>
|
|
|
|
<entry>continue</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry>maclog</entry>
|
|
|
|
<entry>init</entry>
|
|
|
|
<entry></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry>Per-chain (including those associated with
|
|
actions)</entry>
|
|
|
|
<entry>start</entry>
|
|
|
|
<entry></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry></entry>
|
|
|
|
<entry>started</entry>
|
|
|
|
<entry></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry></entry>
|
|
|
|
<entry>stop</entry>
|
|
|
|
<entry></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry></entry>
|
|
|
|
<entry>stopped</entry>
|
|
|
|
<entry></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry></entry>
|
|
|
|
<entry>tcclear</entry>
|
|
|
|
<entry></entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</informaltable></para>
|
|
|
|
<para>Compile-time extension scripts are executed using the Perl 'eval
|
|
`cat <file>`' mechanism. Be sure that each script returns a 'true'
|
|
value; otherwise, the Shorewall-perl compiler will assume that the
|
|
script failed and will abort the compilation.</para>
|
|
|
|
<para>When a script is invoked, the <emphasis
|
|
role="bold">$chainref</emphasis> scalar variable will usually hold a
|
|
reference to a chain table entry.</para>
|
|
|
|
<simplelist>
|
|
<member><emphasis role="bold">$chainref->{name}</emphasis> contains
|
|
the name of the chain</member>
|
|
|
|
<member><emphasis role="bold">$chainref->{table}</emphasis> holds
|
|
the table name</member>
|
|
</simplelist>
|
|
|
|
<para>To add a rule to the chain:</para>
|
|
|
|
<simplelist>
|
|
<member>add_rule $chainref,
|
|
<replaceable>the-rule</replaceable></member>
|
|
</simplelist>
|
|
|
|
<para>Where</para>
|
|
|
|
<simplelist>
|
|
<member><replaceable>the rule</replaceable> is a scalar argument
|
|
holding the rule text. Do not include "-A
|
|
<replaceable>chain-name</replaceable>"</member>
|
|
</simplelist>
|
|
|
|
<para>Example:</para>
|
|
|
|
<simplelist>
|
|
<member>add_rule $chainref, '-j ACCEPT';</member>
|
|
</simplelist>
|
|
|
|
<para>To insert a rule into the chain:</para>
|
|
|
|
<simplelist>
|
|
<member>insert_rule $chainref, <replaceable>rulenum</replaceable>,
|
|
<replaceable>the-rule</replaceable></member>
|
|
</simplelist>
|
|
|
|
<para>The log_rule_limit function works like it does in the shell
|
|
compiler with three exceptions:</para>
|
|
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>You pass the chain reference rather than the name of the
|
|
chain.</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>The commands are 'add' and 'insert' rather than '-A' and
|
|
'-I'.</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>There is only a single "pass as-is to iptables" argument (so
|
|
you must quote that part</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
|
|
<para>Example:</para>
|
|
|
|
<programlisting> log_rule_limit
|
|
'info' ,
|
|
$chainref ,
|
|
$chainref->{name},
|
|
'DROP' ,
|
|
'', #Limit
|
|
'' , #Log tag
|
|
'add'
|
|
'-p tcp '; </programlisting>
|
|
|
|
<para>Here is an example of an actual initdone script used with
|
|
Shorewall 3.4:<programlisting>run_iptables -t mangle -I PREROUTING -p esp -j MARK --set-mark 0x50
|
|
run_iptables -t filter -I INPUT -p udp --dport 1701 -m mark --mark 0x50 -j ACCEPT
|
|
run_iptables -t filter -I OUTPUT -p udp --sport 1701 -j ACCEPT
|
|
</programlisting></para>
|
|
|
|
<para>Here is the corresponding script used with Shorewall
|
|
4.4:<programlisting>use Shorewall::Chains;
|
|
|
|
insert_rule $mangle_table->{PREROUTING}, 1, "-p esp -j MARK --set-mark 0x50";
|
|
insert_rule $filter_table->{INPUT}, 1, "-p udp --dport 1701 -m mark --mark 0x50 -j ACCEPT";
|
|
insert_rule $filter_table->{OUTPUT}, 1, "-p udp --sport 1701 -j ACCEPT";
|
|
|
|
1;</programlisting></para>
|
|
|
|
<para>The initdone script is unique because the $chainref variable is
|
|
not set before the script is called. The above script illustrates how
|
|
the $mangle_table, $filter_table, and $nat_table references can be used
|
|
to add or insert rules in arbitrary chains.</para>
|
|
</section>
|
|
|
|
<section id="ipsets">
|
|
<title>Ipsets</title>
|
|
|
|
<para>Shorewall 4.4 insists that ipset names begin with a letter and be
|
|
composed of alphanumeric characters and underscores (_). When used in a
|
|
Shorewall configuration file, the name must be preceded by a plus sign
|
|
(+) as with the shell-based compiler.</para>
|
|
|
|
<para>Shorewall 4.4.6 re-introduced SAVE_IPSETS=Yes with slightly
|
|
different semantics:</para>
|
|
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>The contents of the ipsets are saved during processing of the
|
|
<command>stop</command> command in addition to during processing of
|
|
the <command>save</command> command.</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>The contents of the ipsets are restored during processing of
|
|
the <command>start</command> command in addition to during
|
|
processing of the <command>restore</command> command. When
|
|
<command>restore</command> is being run when Shorewall is not in the
|
|
stopped state (such as when it is run to recover from a failed
|
|
<command>start</command>, <command>restart</command> or
|
|
<command>refresh</command>) ipsets are not restored.</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Specifying an ipset in <ulink
|
|
url="manpages/shorewall-routestopped.html">shorewall-routestopped
|
|
</ulink>(5) is prohibited when SAVE_IPSETS=Yes.</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
</section>
|
|
</section>
|
|
|
|
<section id="Additional">
|
|
<title>Additional Sources of Information</title>
|
|
|
|
<para>The following articles provide additional information.</para>
|
|
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para><ulink url="Shorewall-perl.html#Incompatibilities">Shorewall
|
|
Perl Incompatibilities</ulink></para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para><ulink url="upgrade_issues.htm">Upgrade Issues</ulink></para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
</section>
|
|
</article>
|