2005-11-16 23:11:52 +01:00
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<?xml version="1.0" encoding="UTF-8"?>
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2008-07-07 22:42:54 +02:00
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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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2005-11-16 23:11:52 +01:00
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<article>
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2008-02-13 20:11:02 +01:00
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<!--ble$Id$-->
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2005-11-16 23:11:52 +01:00
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<articleinfo>
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<title>Shorewall and Multiple Internet Connections</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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2006-07-07 03:04:16 +02:00
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<pubdate><?dbtimestamp format="Y/m/d"?></pubdate>
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2005-11-16 23:11:52 +01:00
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<copyright>
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<year>2005</year>
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2006-01-03 00:21:05 +01:00
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<year>2006</year>
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2007-02-16 00:55:20 +01:00
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<year>2007</year>
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2008-02-13 20:11:02 +01:00
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<year>2008</year>
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2009-01-11 18:22:09 +01:00
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<year>2009</year>
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2005-11-16 23:11:52 +01:00
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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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2006-04-06 01:25:06 +02:00
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<warning>
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2009-02-28 04:45:43 +01:00
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<para>This document describes the Multi-ISP facility in Shorewall 4.3.5
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and later. If you are running an earlier release, please see the
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documentation for that release.</para>
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2006-04-06 01:25:06 +02:00
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</warning>
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2006-05-02 03:09:57 +02:00
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<warning>
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<para>Reading just Shorewall documentation is probably not going to give
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you enough background to use this material. Shorewall may make iptables
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2006-05-02 05:13:58 +02:00
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easy but the Shorewall team doesn't have the resources to be able to
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spoon-feed Linux policy routing to you (please remember that the user's
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manual for a tractor doesn't teach you to grow corn either). You will
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likely need to refer to the following additional information:</para>
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2006-05-02 03:09:57 +02:00
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2006-05-02 05:05:10 +02:00
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<itemizedlist>
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<listitem>
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<para>The LARTC HOWTO: <ulink
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url="http://www.lartc.org">http://www.lartc.org</ulink></para>
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</listitem>
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2006-05-02 03:09:57 +02:00
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2006-05-02 05:05:10 +02:00
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<listitem>
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<para>Output of <command>man ip</command></para>
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</listitem>
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2006-05-02 03:09:57 +02:00
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2006-05-02 05:05:10 +02:00
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<listitem>
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<para>Output of <command>ip route help</command> and <command>ip rule
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help</command></para>
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</listitem>
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</itemizedlist>
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2006-05-02 03:09:57 +02:00
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</warning>
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2007-06-28 22:20:16 +02:00
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<section id="Support">
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2005-12-01 20:35:56 +01:00
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<title>Multiple Internet Connection Support</title>
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2005-11-16 23:11:52 +01:00
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2009-02-28 04:45:43 +01:00
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<para>Shorewall includes limited support for multiple Internet
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connections. Limitations of this support are as follows:</para>
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2006-02-26 21:49:20 +01:00
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<itemizedlist>
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<listitem>
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2009-02-28 04:45:43 +01:00
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<para>It utilizes static routing configuration. If there is a change
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in the routing topopogy, Shorewall must be restarted.</para>
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2006-02-26 21:49:20 +01:00
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</listitem>
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<listitem>
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<para>The routing changes are made and the route cache is purged when
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Shorewall is started <emphasis role="bold">and when Shorewall is
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restarted</emphasis> (unless you specify the "-n" option to
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<command>shorewall restart</command>). Ideally, restarting the packet
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filter should have no effect on routing.</para>
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</listitem>
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2007-01-17 21:47:00 +01:00
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2008-02-13 20:11:02 +01:00
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<listitem>
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<para>For most routing applications, <ulink
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2009-01-30 23:20:22 +01:00
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url="http://www.quagga.net/">Quagga</ulink> is a better solution
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although it requires that your ISPs offer routing protocol
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support.</para>
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2008-02-13 20:11:02 +01:00
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</listitem>
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2006-02-26 21:49:20 +01:00
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</itemizedlist>
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2005-11-16 23:11:52 +01:00
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2007-06-28 22:20:16 +02:00
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<section id="Overview">
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2005-11-16 23:11:52 +01:00
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<title>Overview</title>
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<para>Let's assume that a firewall is connected via two separate
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2008-08-15 03:26:15 +02:00
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Ethernet interfaces to two different ISPs as in the following
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2005-11-16 23:11:52 +01:00
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diagram.</para>
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2006-01-03 16:56:46 +01:00
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<graphic align="center" fileref="images/TwoISPs.png" valign="middle" />
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2005-11-16 23:11:52 +01:00
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<itemizedlist>
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<listitem>
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<para>eth0 connects to ISP1. The IP address of eth0 is
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206.124.146.176 and the ISP's gateway router has IP address
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206.124.146.254.</para>
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</listitem>
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<listitem>
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<para>eth1 connects to ISP 2. The IP address of eth1 is
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130.252.99.27 and the ISP's gateway router has IP address
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130.252.99.254.</para>
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</listitem>
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2005-12-01 23:20:08 +01:00
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<listitem>
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2005-12-01 23:21:31 +01:00
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<para>eth2 connects to the local LAN. Its IP configuration is not
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2005-12-01 23:20:08 +01:00
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relevant to this discussion.</para>
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</listitem>
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2005-11-16 23:11:52 +01:00
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</itemizedlist>
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<para>Each of these <firstterm>providers</firstterm> is described in an
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entry in the file <filename>/etc/shorewall/providers</filename>.</para>
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<para>Entries in <filename>/etc/shorewall/providers</filename> can
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specify that outgoing connections are to be load-balanced between the
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2009-03-17 20:55:34 +01:00
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two ISPs. Entries in <filename>/etc/shorewall/tcrules</filename> and
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<filename>/etc/shorewall/route_rules</filename> can be used to direct
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particular outgoing connections to one ISP or the other. Use of
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<filename>/etc/shorewall/tcrules</filename> is not required for
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<filename>/etc/shorewall/providers</filename> to work, but in most
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cases, you must select a unique MARK value for each provider so
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Shorewall can set up the correct marking rules for you.</para>
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2005-11-16 23:11:52 +01:00
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2005-12-01 20:35:56 +01:00
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<para>When you use the <emphasis role="bold">track</emphasis> option in
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<filename>/etc/shorewall/providers</filename>, connections from the
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2008-08-15 03:26:15 +02:00
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Internet are automatically routed back out of the correct interface and
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2005-12-01 20:35:56 +01:00
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through the correct ISP gateway. This works whether the connection is
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handled by the firewall itself or if it is routed or port-forwarded to a
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system behind the firewall.</para>
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2005-11-16 23:11:52 +01:00
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<para>Shorewall will set up the routing and will update the
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<filename>/etc/iproute2/rt_tables</filename> to include the table names
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2007-01-17 21:47:00 +01:00
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and numbers of the tables that it adds.</para>
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2005-11-16 23:11:52 +01:00
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<caution>
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<para>This feature uses <ulink url="traffic_shaping.htm">packet
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marking</ulink> to control the routing. As a consequence, there are
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some restrictions concerning entries in
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<filename>/etc/shorewall/tcrules</filename>:</para>
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<itemizedlist>
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<listitem>
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<para>Packet marking for traffic control purposes may not be done
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in the PREROUTING table for connections involving providers with
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'track' specified (see below).</para>
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</listitem>
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<listitem>
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2009-03-17 20:55:34 +01:00
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<para>You may not use the SAVE or RESTORE options unless you also
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set HIGH_ROUTE_MARKS=Yes in
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<filename>/etc/shorewall/shorewall.conf</filename>.</para>
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2005-11-16 23:11:52 +01:00
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</listitem>
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<listitem>
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2009-03-17 20:55:34 +01:00
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<para>You may not use connection marking unless you also set
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HIGH_ROUTE_MARKS=Yes in
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<filename>/etc/shorewall/shorewall.conf</filename>.</para>
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2005-11-16 23:11:52 +01:00
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</listitem>
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</itemizedlist>
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</caution>
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<para>The <filename>/etc/shorewall/providers</filename> file can also be
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used in other routing scenarios. See the <ulink
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url="Shorewall_Squid_Usage.html">Squid documentation</ulink> for an
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example.</para>
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</section>
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2007-06-28 22:20:16 +02:00
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<section id="providers">
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2005-11-16 23:11:52 +01:00
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<title>/etc/shorewall/providers File</title>
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<para>Entries in this file have the following columns. As in all
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Shorewall configuration files, enter "-" in a column if you don't want
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to enter any value.</para>
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<variablelist>
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<varlistentry>
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<term>NAME</term>
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<listitem>
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<para>The provider name. Must begin with a letter and consist of
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letters and digits. The provider name becomes the name of the
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generated routing table for this provider.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>NUMBER</term>
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<listitem>
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<para>A number between 1 and 252. This becomes the routing table
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number for the generated table for this provider.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>MARK</term>
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<listitem>
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<para>A mark value used in your /etc/shorewall/tcrules file to
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direct packets to this provider. Shorewall will also mark
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connections that have seen input from this provider with this
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2006-05-07 16:55:44 +02:00
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value and will restore the packet mark in the PREROUTING CHAIN.
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Mark values must be in the range 1-255.</para>
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2009-02-28 04:45:43 +01:00
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<para>Alternatively, you may set HIGH_ROUTE_MARKS=Yes in
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2006-05-07 16:55:44 +02:00
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<filename>/etc/shorewall/shorewall.conf</filename>. This allows
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you to:</para>
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<itemizedlist>
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<listitem>
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<para>Use connection marks for traffic shaping, provided that
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2007-02-02 00:07:35 +01:00
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you assign those marks in the FORWARD chain.</para>
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2006-05-07 16:55:44 +02:00
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</listitem>
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<listitem>
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<para>Use mark values > 255 for provider marks in this
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column. These mark values must be a multiple of 256 in the
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range 256-65280 (hex equivalent 0x100 - 0xFF00 with the
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low-order 8 bits being zero).</para>
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</listitem>
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</itemizedlist>
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2009-03-17 20:55:34 +01:00
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<para>This column may be omitted if you don´t use packet marking
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to direct connections to a particular provider and you don´t
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specify <emphasis role="bold">track</emphasis> in the OPTIONS
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column.</para>
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2005-11-16 23:11:52 +01:00
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>DUPLICATE</term>
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<listitem>
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<para>Gives the name or number of a routing table to duplicate.
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May be 'main' or the name or number of a previously declared
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provider. For most applications, you want to specify 'main' here.
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This field should be be specified as '-' when USE_DEFAULT_RT=Yes
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in <filename>shorewall.conf</filename></para>
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2005-11-16 23:11:52 +01:00
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>INTERFACE</term>
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<listitem>
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2007-12-10 23:53:20 +01:00
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<para>The name of the interface to the provider. Where multiple
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providers share the same interface (which is not recommended), you
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must follow the name of the interface by a colon (":") and the IP
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address assigned by this provider (e.g., eth0:206.124.146.176).
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See <link linkend="Shared">below</link> for additional
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considerations.</para>
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2009-05-21 18:39:43 +02:00
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<para>The interface must have been previously defined in <ulink
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url="manpages/shorewall-interfaces.html">shorewall-interfaces</ulink>
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(5). In general, that interface should not have the
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<option>proxyarp</option> option specified unless
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<option>loose</option> is given in the OPTIONS column of this
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entry.</para>
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2005-11-16 23:11:52 +01:00
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</listitem>
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|
|
</varlistentry>
|
|
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
|
<term>GATEWAY</term>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>The IP address of the provider's Gateway router.</para>
|
|
|
|
|
|
|
|
|
|
<para>You can enter <emphasis role="bold">detect</emphasis> here
|
|
|
|
|
and Shorewall will attempt to automatically determine the gateway
|
|
|
|
|
IP address.</para>
|
|
|
|
|
|
|
|
|
|
<para><emphasis role="bold">Hint:</emphasis> <emphasis
|
|
|
|
|
role="bold">"detect"</emphasis> is appropriate for use in cases
|
|
|
|
|
where the interface named in the INTERFACE column is dynamically
|
2009-04-01 21:53:25 +02:00
|
|
|
|
configured via DHCP etc. Be sure, however, that you don't have
|
|
|
|
|
stale dhcp client state files in <filename
|
|
|
|
|
class="directory">/var/lib/dhcpcd </filename>or
|
|
|
|
|
<filename>/var/lib/dhclient-*.lease</filename> because Shorewall
|
|
|
|
|
may try to use those stale files to determine the gateway
|
|
|
|
|
address.</para>
|
2007-12-05 21:07:25 +01:00
|
|
|
|
|
|
|
|
|
<para>The GATEWAY may be omitted (enter '-') for point-to-point
|
|
|
|
|
links.</para>
|
2005-11-16 23:11:52 +01:00
|
|
|
|
</listitem>
|
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
|
<term>OPTIONS</term>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>A comma-separated list from the following:</para>
|
|
|
|
|
|
|
|
|
|
<variablelist>
|
|
|
|
|
<varlistentry>
|
|
|
|
|
<term>track</term>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>If specified, connections FROM this interface are to
|
|
|
|
|
be tracked so that responses may be routed back out this
|
|
|
|
|
same interface.</para>
|
|
|
|
|
|
2008-08-15 03:26:15 +02:00
|
|
|
|
<para>You want to specify 'track' if Internet hosts will be
|
2005-11-16 23:11:52 +01:00
|
|
|
|
connecting to local servers through this provider. Any time
|
2009-01-07 17:25:14 +01:00
|
|
|
|
that you specify 'track', you will normally want to also
|
2009-03-03 21:05:30 +01:00
|
|
|
|
specify 'balance' (see below). 'track' will also ensure that
|
|
|
|
|
outgoing connections remain stay anchored to a single
|
|
|
|
|
provider and don't try to switch providers when route cache
|
|
|
|
|
entries expire.</para>
|
2005-12-01 20:35:56 +01:00
|
|
|
|
|
|
|
|
|
<para>Use of this feature requires that your kernel and
|
2007-09-19 22:51:57 +02:00
|
|
|
|
iptables include CONNMARK target and connmark match support
|
2009-05-29 15:45:31 +02:00
|
|
|
|
(<emphasis role="bold">Warning</emphasis>: Until recently,
|
|
|
|
|
standard <trademark>Debian</trademark> and
|
|
|
|
|
<trademark>Ubuntu</trademark> kernels lacked that support.
|
|
|
|
|
<emphasis>Both Lenny and Jaunty do have the proper
|
|
|
|
|
support</emphasis>).</para>
|
2005-12-01 20:35:56 +01:00
|
|
|
|
|
2006-01-03 00:21:05 +01:00
|
|
|
|
<important>
|
|
|
|
|
<para>If you are using
|
|
|
|
|
<filename>/etc/shorewall/providers</filename> because you
|
2008-08-15 03:26:15 +02:00
|
|
|
|
have multiple Internet connections, we recommend that you
|
2009-03-17 20:55:34 +01:00
|
|
|
|
specify <emphasis role="bold">track</emphasis> even if you
|
|
|
|
|
don't need it. It helps maintain long-term connections in
|
|
|
|
|
which there are significant periods with no
|
|
|
|
|
traffic.</para>
|
2006-01-03 00:21:05 +01:00
|
|
|
|
</important>
|
2005-11-16 23:11:52 +01:00
|
|
|
|
</listitem>
|
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
|
<term>balance</term>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
2009-03-17 20:55:34 +01:00
|
|
|
|
<para>The providers that have <emphasis
|
|
|
|
|
role="bold">balance</emphasis> specified will get outbound
|
|
|
|
|
traffic load-balanced among them. Balancing will not be
|
|
|
|
|
perfect, as it is route based, and routes are cached. This
|
|
|
|
|
means that routes to often-used sites will always be over
|
|
|
|
|
the same provider.</para>
|
2005-11-16 23:11:52 +01:00
|
|
|
|
|
|
|
|
|
<para>By default, each provider is given the same weight (1)
|
2005-12-01 20:35:56 +01:00
|
|
|
|
. You can change the weight of a given provider by following
|
2009-03-17 20:55:34 +01:00
|
|
|
|
<emphasis role="bold">balance</emphasis> with "=" and the
|
|
|
|
|
desired weight (e.g., balance=2). The weights reflect the
|
|
|
|
|
relative bandwidth of the providers connections and should
|
|
|
|
|
be small numbers since the kernel actually creates
|
|
|
|
|
additional default routes for each weight increment.</para>
|
2006-01-03 00:21:05 +01:00
|
|
|
|
|
|
|
|
|
<important>
|
|
|
|
|
<para>If you are using
|
|
|
|
|
<filename>/etc/shorewall/providers</filename> because you
|
2008-08-15 03:26:15 +02:00
|
|
|
|
have multiple Internet connections, we recommend that you
|
2009-03-17 20:55:34 +01:00
|
|
|
|
specify <emphasis role="bold">balance</emphasis> even if
|
|
|
|
|
you don't need it. You can still use entries in
|
2009-04-01 21:53:25 +02:00
|
|
|
|
<filename>/etc/shorewall/tcrules</filename> and
|
|
|
|
|
<filename>/etc/shorewall/route_rules</filename> to force
|
|
|
|
|
all traffic to one provider or another.<note>
|
2009-01-07 17:25:14 +01:00
|
|
|
|
<para>If you don't heed this advice then please read
|
|
|
|
|
and follow the advice in <ulink
|
|
|
|
|
url="FAQ.htm#faq57">FAQ 57</ulink> and <ulink
|
|
|
|
|
url="FAQ.htm#faq58">FAQ 58</ulink>.</para>
|
2006-09-04 02:46:08 +02:00
|
|
|
|
</note></para>
|
2006-01-03 00:21:05 +01:00
|
|
|
|
</important>
|
2006-07-20 19:20:36 +02:00
|
|
|
|
|
|
|
|
|
<important>
|
2009-03-17 20:55:34 +01:00
|
|
|
|
<para>If you specify <emphasis
|
|
|
|
|
role="bold">balance</emphasis> and still find that all
|
2006-07-20 19:20:36 +02:00
|
|
|
|
traffic is going out through only one provider, you may
|
|
|
|
|
need to install a kernel built with
|
|
|
|
|
CONFIG_IP_ROUTE_MULTIPATH_CACHED=n. Several users have
|
2006-08-26 17:49:12 +02:00
|
|
|
|
reported that this change has corrected similar
|
|
|
|
|
problems.</para>
|
|
|
|
|
|
2006-09-04 16:45:19 +02:00
|
|
|
|
<para>The SuSE 10.0 kernel is subject to this problem, and
|
2006-08-26 17:49:12 +02:00
|
|
|
|
<ulink
|
|
|
|
|
url="https://bugzilla.novell.com/show_bug.cgi?id=190908">
|
|
|
|
|
a kernel oops may result in this circumstance.</ulink>
|
|
|
|
|
SUSE 10.1 and SLES 10 have
|
|
|
|
|
CONFIG_IP_ROUTE_MULTIPATH_CACHED=n set by default. The
|
|
|
|
|
source of the problem seems to be <ulink
|
|
|
|
|
url="http://news.gmane.org/find-root.php?message_id=%3c00da01c5b35a%24b12b9860%241b00a8c0%40cruncher%3e">an
|
|
|
|
|
incompatibility between the LARTC patches and
|
|
|
|
|
CONFIG_IP_ROUTE_MULTIPATH_CACHED.</ulink></para>
|
2006-07-20 19:20:36 +02:00
|
|
|
|
</important>
|
2005-11-16 23:11:52 +01:00
|
|
|
|
</listitem>
|
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
|
<term>loose</term>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Do not include routing rules that force traffic whose
|
|
|
|
|
source IP is an address of the INTERFACE to be routed to
|
|
|
|
|
this provider. Useful for defining providers that are to be
|
2009-04-01 21:53:25 +02:00
|
|
|
|
used only when the appropriate packet mark is
|
|
|
|
|
applied.</para>
|
2005-11-16 23:11:52 +01:00
|
|
|
|
</listitem>
|
|
|
|
|
</varlistentry>
|
2006-08-08 18:22:15 +02:00
|
|
|
|
|
|
|
|
|
<varlistentry>
|
2009-02-28 04:45:43 +01:00
|
|
|
|
<term>optional</term>
|
2006-08-08 18:22:15 +02:00
|
|
|
|
|
|
|
|
|
<listitem>
|
2009-06-16 23:03:15 +02:00
|
|
|
|
<note>
|
|
|
|
|
<para>This option is deprecated in favor of the
|
|
|
|
|
<option>optional</option> <ulink
|
|
|
|
|
url="manpages/shorewall-interfaces.html">interface
|
|
|
|
|
option</ulink>. That option performs the same
|
|
|
|
|
function.</para>
|
|
|
|
|
</note>
|
|
|
|
|
|
2009-03-17 20:55:34 +01:00
|
|
|
|
<para>Shorewall will determine if this interface is up and
|
2009-04-01 21:53:25 +02:00
|
|
|
|
has a configured IP address. If it is not, a warning is
|
2006-08-08 18:22:15 +02:00
|
|
|
|
issued and this provider is not configured.</para>
|
2006-08-26 17:49:12 +02:00
|
|
|
|
|
|
|
|
|
<note>
|
2009-03-17 20:55:34 +01:00
|
|
|
|
<para><emphasis role="bold">optional</emphasis> is
|
|
|
|
|
designed to detect interface states that will cause
|
|
|
|
|
<command>shorewall start</command> or <command>shorewall
|
|
|
|
|
restart</command> to fail; just because an interface is in
|
|
|
|
|
a state that Shorewall can [re]start without error doesn't
|
|
|
|
|
mean that traffic can actually be sent through the
|
|
|
|
|
interface.</para>
|
2007-08-10 22:55:54 +02:00
|
|
|
|
|
2009-02-28 04:45:43 +01:00
|
|
|
|
<para>You can supply an 'isusable' <ulink
|
2007-08-10 22:55:54 +02:00
|
|
|
|
url="shorewall_extension_scripts.htm">extension
|
|
|
|
|
script</ulink> to extend Shorewall's interface state
|
2009-04-01 21:53:25 +02:00
|
|
|
|
detection. See also the <link
|
|
|
|
|
linkend="LinkMonitor">Gateway Monitoring and
|
|
|
|
|
Failover</link> section below.</para>
|
2006-08-26 17:49:12 +02:00
|
|
|
|
</note>
|
2006-08-08 18:22:15 +02:00
|
|
|
|
</listitem>
|
|
|
|
|
</varlistentry>
|
2008-02-11 22:23:48 +01:00
|
|
|
|
|
|
|
|
|
<varlistentry>
|
2009-02-28 04:45:43 +01:00
|
|
|
|
<term>src=<replaceable>source-address</replaceable></term>
|
2008-02-11 22:23:48 +01:00
|
|
|
|
|
|
|
|
|
<listitem>
|
2008-02-13 20:11:02 +01:00
|
|
|
|
<para>Specifies the source address to use when routing to
|
2008-02-11 22:23:48 +01:00
|
|
|
|
this provider and none is known (the local client has bound
|
|
|
|
|
to the 0 address). May not be specified when an
|
|
|
|
|
<replaceable>address</replaceable> is given in the INTERFACE
|
|
|
|
|
column. If this option is not used, Shorewall substitutes
|
|
|
|
|
the primary IP address on the interface named in the
|
|
|
|
|
INTERFACE column.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
|
|
<varlistentry>
|
2009-02-28 04:45:43 +01:00
|
|
|
|
<term>mtu=<replaceable>number</replaceable></term>
|
2008-02-11 22:23:48 +01:00
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Specifies the MTU when forwarding through this
|
|
|
|
|
provider. If not given, the MTU of the interface named in
|
|
|
|
|
the INTERFACE column is assumed.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</varlistentry>
|
2009-01-06 19:33:19 +01:00
|
|
|
|
|
|
|
|
|
<varlistentry>
|
2009-04-29 23:31:55 +02:00
|
|
|
|
<term>fallback[=<replaceable>weight</replaceable>]</term>
|
2009-01-06 19:33:19 +01:00
|
|
|
|
|
|
|
|
|
<listitem>
|
2009-01-07 17:25:14 +01:00
|
|
|
|
<para>Indicates that a default route through the provider
|
2009-04-01 21:53:25 +02:00
|
|
|
|
should be added to the <firstterm>default</firstterm>
|
|
|
|
|
routing table (table 253). If a
|
|
|
|
|
<replaceable>weight</replaceable> is given, a balanced route
|
|
|
|
|
is added with the weight of this provider equal to the
|
2009-01-07 17:25:14 +01:00
|
|
|
|
specified <replaceable>weight</replaceable>. If the option
|
2009-04-01 21:53:25 +02:00
|
|
|
|
is given without a <replaceable>weight</replaceable>, a
|
2009-01-07 17:25:14 +01:00
|
|
|
|
separate default route is added through the provider's
|
|
|
|
|
gateway; the route has a metric equal to the provider's
|
|
|
|
|
NUMBER. The option is ignored with a warning message if
|
2009-01-06 19:33:19 +01:00
|
|
|
|
USE_DEFAULT_RT=Yes in
|
|
|
|
|
<filename>shorewall.conf</filename>.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</varlistentry>
|
2005-11-16 23:11:52 +01:00
|
|
|
|
</variablelist>
|
2006-10-07 23:12:23 +02:00
|
|
|
|
|
2009-03-17 20:55:34 +01:00
|
|
|
|
<para>For those of you who are confused between<emphasis
|
|
|
|
|
role="bold"> track</emphasis> and <emphasis
|
2006-10-07 23:12:23 +02:00
|
|
|
|
role="bold">balance</emphasis>:</para>
|
|
|
|
|
|
|
|
|
|
<itemizedlist>
|
|
|
|
|
<listitem>
|
|
|
|
|
<para><emphasis role="bold">track</emphasis> governs incoming
|
2009-04-01 21:53:25 +02:00
|
|
|
|
connections (but is also useful for binding long-running
|
|
|
|
|
connections to the same interface).</para>
|
2006-10-07 23:12:23 +02:00
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para><emphasis role="bold">balance</emphasis> governs
|
|
|
|
|
outgoing connections.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</itemizedlist>
|
2005-11-16 23:11:52 +01:00
|
|
|
|
</listitem>
|
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
|
<term>COPY</term>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
2009-03-17 20:55:34 +01:00
|
|
|
|
<para>A comma-separated list of interface names. Wildcards
|
2007-09-17 22:30:59 +02:00
|
|
|
|
specified using an asterisk ("*") are permitted (e.g., tun*
|
|
|
|
|
).</para>
|
|
|
|
|
|
2005-11-16 23:11:52 +01:00
|
|
|
|
<para>When you specify an existing table in the DUPLICATE column,
|
|
|
|
|
Shorewall copies all routes through the interface specified in the
|
2007-09-17 22:30:59 +02:00
|
|
|
|
INTERFACE column plus the interfaces listed in this column.
|
|
|
|
|
Normally, you will list all interfaces on your firewall in this
|
2008-08-15 03:26:15 +02:00
|
|
|
|
column except those Internet interfaces specified in the INTERFACE
|
2007-09-19 22:51:57 +02:00
|
|
|
|
column of entries in this file.</para>
|
2005-11-16 23:11:52 +01:00
|
|
|
|
</listitem>
|
|
|
|
|
</varlistentry>
|
|
|
|
|
</variablelist>
|
|
|
|
|
</section>
|
|
|
|
|
|
2007-06-28 22:20:16 +02:00
|
|
|
|
<section id="Providers">
|
2005-11-16 23:11:52 +01:00
|
|
|
|
<title>What an entry in the Providers File Does</title>
|
|
|
|
|
|
|
|
|
|
<para>Adding another entry in the providers file simply creates an
|
2009-04-01 21:53:25 +02:00
|
|
|
|
alternate routing table for you (see the<ulink
|
|
|
|
|
url="http://www.lartc.org"> LARTC Howto</ulink>). The table will usually
|
|
|
|
|
contain two routes:</para>
|
2007-12-05 21:07:25 +01:00
|
|
|
|
|
|
|
|
|
<orderedlist>
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>A host route to the specified GATEWAY through the specified
|
|
|
|
|
INTERFACE.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>A default route through the GATEWAY.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</orderedlist>
|
|
|
|
|
|
|
|
|
|
<para>Note that the first route is omitted if "-" is specified as the
|
|
|
|
|
GATEWAY; in that case, the default route does not specify a gateway
|
|
|
|
|
(point-to-point link).</para>
|
|
|
|
|
|
|
|
|
|
<para>If the DUPLICATE column is non-empty, then routes from the table
|
|
|
|
|
named in that column are copied into the new table. By default, all
|
|
|
|
|
routes (except default routes) are copied. The set of routes copied can
|
|
|
|
|
be restricted using the COPY column which lists the interfaces whose
|
|
|
|
|
routes you want copied. You will generally want to include all local
|
|
|
|
|
interfaces in this list. You should exclude the loopback interface (lo)
|
2009-04-01 21:53:25 +02:00
|
|
|
|
and any interfaces that do not have an IP configuration. You should also
|
|
|
|
|
omit interfaces like <emphasis role="bold">tun</emphasis> interfaces
|
|
|
|
|
that are created dynamically. Traffic to networks handled by those
|
|
|
|
|
interfaces should be routed through the main table using entries in
|
|
|
|
|
<filename>/etc/shorewall/route_rules</filename> (see Example 2 <link
|
|
|
|
|
linkend="Examples">below</link>) or by using <link
|
|
|
|
|
linkend="USE_DEFAULT_RT">USE_DEFAULT_RT=Yes</link>.</para>
|
2007-12-05 21:07:25 +01:00
|
|
|
|
|
|
|
|
|
<para>In addition:</para>
|
2005-11-16 23:11:52 +01:00
|
|
|
|
|
|
|
|
|
<orderedlist>
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Unless <emphasis role="bold">loose</emphasis> is specified, an
|
|
|
|
|
ip rule is generated for each IP address on the INTERFACE that
|
|
|
|
|
routes traffic from that address through the associated routing
|
|
|
|
|
table.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>If you specify <emphasis role="bold">track</emphasis>, then
|
|
|
|
|
connections which have had at least one packet arrive on the
|
|
|
|
|
interface listed in the INTERFACE column have their connection mark
|
|
|
|
|
set to the value in the MARK column. In the PREROUTING chain,
|
2005-12-01 20:35:56 +01:00
|
|
|
|
packets with a connection mark have their packet mark set to the
|
|
|
|
|
value of the associated connection mark; packets marked in this way
|
|
|
|
|
bypass any prerouting rules that you create in
|
|
|
|
|
<filename>/etc/shorewall/tcrules</filename>. This ensures that
|
2005-11-16 23:11:52 +01:00
|
|
|
|
packets associated with connections from outside are always routed
|
|
|
|
|
out of the correct interface.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>If you specify <emphasis role="bold">balance</emphasis>, then
|
|
|
|
|
Shorewall will replace the 'default' route with weight 100 in the
|
|
|
|
|
'main' routing table with a load-balancing route among those
|
|
|
|
|
gateways where <emphasis role="bold">balance</emphasis> was
|
|
|
|
|
specified. So if you configure default routes, be sure that their
|
|
|
|
|
weight is less than 100 or the route added by Shorewall will not be
|
|
|
|
|
used.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</orderedlist>
|
|
|
|
|
|
|
|
|
|
<para>That's <emphasis role="bold">all</emphasis> that these entries do.
|
2005-11-22 17:39:38 +01:00
|
|
|
|
You still have to follow the principle stated in the <ulink
|
|
|
|
|
url="Shorewall_and_Routing.html">Shorewall Routing
|
|
|
|
|
documentation</ulink>:</para>
|
2005-11-16 23:11:52 +01:00
|
|
|
|
|
|
|
|
|
<orderedlist>
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Routing determines where packets are to be sent.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Once routing determines where the packet is to go, the
|
|
|
|
|
firewall (Shorewall) determines if the packet is allowed to go
|
|
|
|
|
there.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</orderedlist>
|
|
|
|
|
|
|
|
|
|
<para>The bottom line is that if you want traffic to go out through a
|
|
|
|
|
particular provider then you <emphasis>must </emphasis>mark that traffic
|
|
|
|
|
with the provider's MARK value in
|
|
|
|
|
<filename>/etc/shorewall/tcrules</filename> and you must do that marking
|
2007-01-17 21:47:00 +01:00
|
|
|
|
in the PREROUTING chain; or, you must provide the appropriate rules in
|
|
|
|
|
<filename>/etc/shorewall/route_rules</filename>.</para>
|
2005-11-16 23:11:52 +01:00
|
|
|
|
</section>
|
|
|
|
|
|
2009-04-01 21:53:25 +02:00
|
|
|
|
<section>
|
|
|
|
|
<title>/etc/shorewall/masq and Multi-ISP</title>
|
|
|
|
|
|
|
|
|
|
<para>If you masquerade a local network, you will need to add masquerade
|
|
|
|
|
rules for both external interfaces. Referring to the diagram above, if
|
|
|
|
|
each of the interfaces has only a single IP address and you have no
|
|
|
|
|
systems with public IP addresses behind your firewall, then I suggest
|
|
|
|
|
the following simple entries:</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>#INTERFACE SOURCE ADDRESS
|
|
|
|
|
eth0 0.0.0.0/0 206.124.146.176
|
|
|
|
|
eth1 0.0.0.0/0 130.252.99.27</programlisting>
|
|
|
|
|
|
|
|
|
|
<para>If you have a public subnet (for example 206.124.146.176/30)
|
|
|
|
|
behind your firewall, then use exclusion:</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>#INTERFACE SOURCE ADDRESS
|
|
|
|
|
eth0 !206.124.146.176/29 206.124.146.176
|
|
|
|
|
eth1 0.0.0.0/0 130.252.99.27</programlisting>
|
|
|
|
|
|
|
|
|
|
<para>Note that exclusion is only used on the interface corresponding to
|
|
|
|
|
internal subnetwork.</para>
|
|
|
|
|
|
|
|
|
|
<para>If you have multiple IP addresses on one of your interfaces, you
|
|
|
|
|
can use a similar technique -- simple exclude the smallest network that
|
|
|
|
|
contains all of those addresses from being masqueraded.</para>
|
|
|
|
|
|
|
|
|
|
<warning>
|
|
|
|
|
<para>Entries in <filename>/etc/shorewall/masq</filename> have no
|
|
|
|
|
effect on which ISP a particular connection will be sent through. That
|
|
|
|
|
is rather the purpose of entries in
|
|
|
|
|
<filename>/etc/shorewall/tcrules</filename> and
|
|
|
|
|
<filename>/etc/shorewall/route_rules</filename>.</para>
|
|
|
|
|
</warning>
|
|
|
|
|
</section>
|
|
|
|
|
|
2007-02-11 19:35:38 +01:00
|
|
|
|
<section id="Martians">
|
|
|
|
|
<title>Martians</title>
|
|
|
|
|
|
|
|
|
|
<para>One problem that often arises with Multi-ISP configuration is
|
2008-08-15 03:26:15 +02:00
|
|
|
|
'Martians'. If your Internet interfaces are configured with the
|
2007-02-11 19:35:38 +01:00
|
|
|
|
<emphasis role="bold">routefilter</emphasis> option in
|
|
|
|
|
<filename>/etc/shorewall/interfaces</filename> (remember that if you set
|
|
|
|
|
that option, you should also select <emphasis
|
|
|
|
|
role="bold">logmartians</emphasis>), then things may not work correctly
|
|
|
|
|
and you will see messages like this:</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>Feb 9 17:23:45 gw.ilinx kernel: martian source 206.124.146.176 from 64.86.88.116, on dev eth1
|
|
|
|
|
Feb 9 17:23:45 gw.ilinx kernel: ll header: 00:a0:24:2a:1f:72:00:13:5f:07:97:05:08:00</programlisting>
|
|
|
|
|
|
|
|
|
|
<para>The above message is somewhat awkwardly phrased. The source IP in
|
2009-03-17 20:55:34 +01:00
|
|
|
|
this incoming packet was 64.86.88.116 and the destination IP address was
|
2007-02-11 19:35:38 +01:00
|
|
|
|
206.124.146.176. Another gotcha is that the incoming packet has already
|
|
|
|
|
had the destination IP address changed for DNAT or because the original
|
|
|
|
|
outgoing connection was altered by an entry in
|
|
|
|
|
<filename>/etc/shorewall/masq</filename> (SNAT or Masquerade). So the
|
|
|
|
|
destination IP address (206.124.146.176) may not have been the
|
|
|
|
|
destination IP address in the packet as it was initially
|
|
|
|
|
received.</para>
|
|
|
|
|
|
|
|
|
|
<para>There a couple of common causes for these problems:</para>
|
|
|
|
|
|
|
|
|
|
<orderedlist>
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>You have connected both of your external interfaces to the
|
|
|
|
|
same hub/switch. Connecting multiple firewall interfaces to a common
|
|
|
|
|
hub or switch is always a bad idea that will result in
|
|
|
|
|
hard-to-diagnose problems.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>You are specifying both the <emphasis
|
|
|
|
|
role="bold">loose</emphasis> and <emphasis
|
2009-03-17 20:55:34 +01:00
|
|
|
|
role="bold">balance</emphasis> options on your provider(s). This can
|
|
|
|
|
cause individual connections to ping-pong back and forth between the
|
|
|
|
|
interfaces which is almost guaranteed to cause problems.</para>
|
2007-02-11 19:35:38 +01:00
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
2009-03-17 20:55:34 +01:00
|
|
|
|
<para>You are redirecting traffic from the firewall system out of
|
|
|
|
|
one interface or the other using packet marking in your
|
2007-02-11 19:35:38 +01:00
|
|
|
|
<filename>/etc/shorewall/tcrules</filename> file. A better approach
|
|
|
|
|
is to configure the application to use the appropriate local IP
|
|
|
|
|
address (the IP address of the interface that you want the
|
|
|
|
|
application to use). See <link linkend="Local">below</link>.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</orderedlist>
|
2007-02-12 17:17:09 +01:00
|
|
|
|
|
|
|
|
|
<para>If all else fails, remove the <emphasis
|
|
|
|
|
role="bold">routefilter</emphasis> option from your external interfaces.
|
|
|
|
|
If you do this, you may wish to add rules to log and drop packets from
|
|
|
|
|
the Internet that have source addresses in your local networks. For
|
|
|
|
|
example, if the local LAN in the above diagram is 192.168.1.0/24, then
|
2007-02-12 23:58:15 +01:00
|
|
|
|
you would add this rule:</para>
|
2007-02-12 17:17:09 +01:00
|
|
|
|
|
|
|
|
|
<programlisting>#ACTION SOURCE DEST
|
|
|
|
|
DROP:info net:192.168.1.0/24 all</programlisting>
|
|
|
|
|
|
|
|
|
|
<para>Be sure the above rule is added before any other rules with
|
|
|
|
|
<emphasis>net</emphasis> in the SOURCE column.</para>
|
2007-02-11 19:35:38 +01:00
|
|
|
|
</section>
|
|
|
|
|
|
2007-06-28 22:20:16 +02:00
|
|
|
|
<section id="Example1">
|
|
|
|
|
<title id="Example">Example</title>
|
2005-11-16 23:11:52 +01:00
|
|
|
|
|
|
|
|
|
<para>The configuration in the figure at the top of this section would
|
|
|
|
|
be specified in <filename>/etc/shorewall/providers</filename> as
|
2005-12-01 20:35:56 +01:00
|
|
|
|
follows.</para>
|
2005-11-16 23:11:52 +01:00
|
|
|
|
|
|
|
|
|
<programlisting>#NAME NUMBER MARK DUPLICATE INTERFACE GATEWAY OPTIONS COPY
|
|
|
|
|
ISP1 1 1 main eth0 206.124.146.254 track,balance eth2
|
|
|
|
|
ISP2 2 2 main eth1 130.252.99.254 track,balance eth2</programlisting>
|
|
|
|
|
|
|
|
|
|
<para>Other configuration files go something like this:</para>
|
|
|
|
|
|
|
|
|
|
<para><filename>/etc/shorewall/interfaces</filename>:</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>#ZONE INTERFACE BROADCAST OPTIONS
|
|
|
|
|
net eth0 detect …
|
|
|
|
|
net eth1 detect …</programlisting>
|
|
|
|
|
|
|
|
|
|
<para><filename>/etc/shorewall/policy</filename>:</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>#SOURCE DESTINATION POLICY LIMIT:BURST
|
|
|
|
|
net net DROP</programlisting>
|
|
|
|
|
|
2009-04-01 21:53:25 +02:00
|
|
|
|
<para><filename>/etc/shorewall/masq</filename>:</para>
|
2006-01-03 02:21:10 +01:00
|
|
|
|
|
2009-04-01 21:53:25 +02:00
|
|
|
|
<programlisting>#INTERFACE SOURCE ADDRESS
|
|
|
|
|
eth0 0.0.0.0/0 206.124.146.176
|
|
|
|
|
eth1 0.0.0.0/0 130.252.99.27</programlisting>
|
|
|
|
|
</section>
|
2006-03-27 18:35:32 +02:00
|
|
|
|
|
2009-04-01 21:53:25 +02:00
|
|
|
|
<section id="Applications">
|
|
|
|
|
<title>Routing a Particular Application Through a Specific
|
|
|
|
|
Interface</title>
|
2005-11-16 23:11:52 +01:00
|
|
|
|
|
2009-04-01 21:53:25 +02:00
|
|
|
|
<para>This continues the example in the preceding section.</para>
|
2005-11-16 23:11:52 +01:00
|
|
|
|
|
|
|
|
|
<para>Now suppose that you want to route all outgoing SMTP traffic from
|
|
|
|
|
your local network through ISP 2. You would make this entry in <ulink
|
2009-04-01 21:53:25 +02:00
|
|
|
|
url="traffic_shaping.htm">/etc/shorewall/tcrules</ulink> (and if you are
|
|
|
|
|
running a version of Shorewall earlier than 3.0.0, you would set
|
|
|
|
|
TC_ENABLED=Yes in <ulink
|
|
|
|
|
url="???">/etc/shorewall/shorewall.conf</ulink>).</para>
|
2005-11-16 23:11:52 +01:00
|
|
|
|
|
|
|
|
|
<programlisting>#MARK SOURCE DEST PROTO PORT(S) CLIENT USER TEST
|
|
|
|
|
# PORT(S)
|
|
|
|
|
2:P <local network> 0.0.0.0/0 tcp 25</programlisting>
|
2009-04-01 21:53:25 +02:00
|
|
|
|
|
|
|
|
|
<para>Note that traffic from the firewall itself must be handled in a
|
|
|
|
|
different rule:</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>#MARK SOURCE DEST PROTO PORT(S) CLIENT USER TEST
|
|
|
|
|
# PORT(S)
|
|
|
|
|
2 $FW 0.0.0.0/0 tcp 25</programlisting>
|
2005-11-16 23:11:52 +01:00
|
|
|
|
</section>
|
2006-05-01 23:40:05 +02:00
|
|
|
|
|
2009-05-23 16:43:37 +02:00
|
|
|
|
<section id="PortForwarding">
|
|
|
|
|
<title>Port Forwarding</title>
|
|
|
|
|
|
|
|
|
|
<para>Shorewall provides considerable flexibility for port forwarding in
|
|
|
|
|
a multi-ISP environment.</para>
|
|
|
|
|
|
|
|
|
|
<para>Normal port forwarding rules such as the following will forward
|
|
|
|
|
from both providers.</para>
|
|
|
|
|
|
|
|
|
|
<para><filename>/etc/shorewall/rules</filename>:</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S) SOURCE ORIGINAL
|
|
|
|
|
# PORTS(S) DEST
|
|
|
|
|
DNAT net loc:192.168.1.3 tcp 25</programlisting>
|
|
|
|
|
|
|
|
|
|
<para>Continuing the above example, to forward only connection requests
|
|
|
|
|
from ISP 1, you can either:</para>
|
|
|
|
|
|
|
|
|
|
<orderedlist>
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Qualify the SOURCE by ISP 1's interface:</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S) SOURCE ORIGINAL
|
|
|
|
|
# PORTS(S) DEST
|
|
|
|
|
DNAT net<emphasis role="bold">:eth0</emphasis> loc:192.168.1.3 tcp 25</programlisting>
|
|
|
|
|
|
|
|
|
|
<para>or</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Specify the IP address of ISP 1 in the ORIGINAL DEST
|
|
|
|
|
column:</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S) SOURCE ORIGINAL
|
|
|
|
|
# PORTS(S) DEST
|
|
|
|
|
DNAT net loc:192.168.1.3 tcp 25 <emphasis
|
|
|
|
|
role="bold">- 206.124.146.176</emphasis></programlisting>
|
|
|
|
|
</listitem>
|
|
|
|
|
</orderedlist>
|
|
|
|
|
</section>
|
|
|
|
|
|
2007-07-16 20:24:23 +02:00
|
|
|
|
<section id="morethan2">
|
|
|
|
|
<title>More than 2 Providers</title>
|
|
|
|
|
|
|
|
|
|
<para>When there are more than two providers, you need to extend the
|
|
|
|
|
two-provider case in the expected way:</para>
|
|
|
|
|
|
|
|
|
|
<orderedlist>
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>For each external address, you need an entry in
|
|
|
|
|
<filename>/etc/shorewall/masq</filename> to handle the case where a
|
|
|
|
|
connection using that address as the SOURCE is sent out of the
|
|
|
|
|
interfaces other than the one that the address is configured
|
|
|
|
|
on.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>For each external interface, you need to add an entry to
|
2009-04-01 21:53:25 +02:00
|
|
|
|
<filename>/etc/shorewall/masq</filename>.</para>
|
2007-07-16 20:24:23 +02:00
|
|
|
|
</listitem>
|
|
|
|
|
</orderedlist>
|
|
|
|
|
|
|
|
|
|
<para>If we extend the above example to add eth3 with IP address
|
|
|
|
|
16.105.78.4 with gateway 16.105.78.254, then:</para>
|
|
|
|
|
|
|
|
|
|
<para><filename>/etc/shorewall/providers</filename>:<programlisting>#NAME NUMBER MARK DUPLICATE INTERFACE GATEWAY OPTIONS COPY
|
|
|
|
|
ISP1 1 1 main eth0 206.124.146.254 track,balance eth2
|
|
|
|
|
ISP2 2 2 main eth1 130.252.99.254 track,balance eth2
|
|
|
|
|
ISP3 3 3 main eth3 16.105.78.254 track,balance eth2</programlisting></para>
|
|
|
|
|
|
|
|
|
|
<para><filename>/etc/shorewall/masq</filename>:<programlisting>#INTERFACE SUBNET ADDRESS
|
2009-04-01 21:53:25 +02:00
|
|
|
|
eth0 0.0.0.0/0 206.124.146.176
|
|
|
|
|
eth1 0.0.0.0/0 130.252.99.27
|
|
|
|
|
eth3 0.0.0.0/0 16.105.78.4</programlisting></para>
|
2007-07-16 20:24:23 +02:00
|
|
|
|
</section>
|
|
|
|
|
|
2007-02-11 19:35:38 +01:00
|
|
|
|
<section id="Local">
|
2006-10-20 17:41:54 +02:00
|
|
|
|
<title>Applications running on the Firewall</title>
|
|
|
|
|
|
2009-04-01 21:53:25 +02:00
|
|
|
|
<para>As <link linkend="Applications">noted above</link>, separate
|
|
|
|
|
entries in <filename>/etc/shorewall/tcrules</filename> are required for
|
|
|
|
|
traffic originating from the firewall.</para>
|
|
|
|
|
|
2006-10-20 17:41:54 +02:00
|
|
|
|
<para>Experience has shown that in some cases, problems occur with
|
2007-02-11 19:35:38 +01:00
|
|
|
|
applications running on the firewall itself. This is especially true
|
|
|
|
|
when you have specified <emphasis role="bold">routefilter</emphasis> on
|
|
|
|
|
your external interfaces in /etc/shorewall/interfaces (see <link
|
|
|
|
|
linkend="Martians">above</link>). When this happens, it is suggested
|
|
|
|
|
that you have the application use specific local IP addresses rather
|
|
|
|
|
than 0.</para>
|
2006-10-20 17:41:54 +02:00
|
|
|
|
|
|
|
|
|
<para>Examples:</para>
|
|
|
|
|
|
|
|
|
|
<itemizedlist>
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Squid: In <filename>squid.conf</filename>, set <emphasis
|
|
|
|
|
role="bold">tcp_outgoing_address</emphasis> to the IP address of the
|
|
|
|
|
interface that you want Squid to use.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>In OpenVPN, set <emphasis role="bold">local
|
|
|
|
|
</emphasis>(<emphasis role="bold">--local</emphasis> on the command
|
|
|
|
|
line) to the IP address that you want the server to receive
|
|
|
|
|
connections on.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</itemizedlist>
|
2007-08-25 01:47:13 +02:00
|
|
|
|
|
|
|
|
|
<para>Note that some traffic originating on the firewall doesn't have a
|
|
|
|
|
SOURCE IP address before routing. At least one Shorewall user reports
|
|
|
|
|
that an entry in <filename>/etc/shorewall/route_rules</filename> with
|
|
|
|
|
'lo' in the SOURCE column seems to be the most reliable way to direct
|
|
|
|
|
such traffic to a particular ISP.</para>
|
2006-10-20 17:41:54 +02:00
|
|
|
|
</section>
|
|
|
|
|
|
2007-06-28 22:20:16 +02:00
|
|
|
|
<section id="route_rules">
|
2006-05-01 23:40:05 +02:00
|
|
|
|
<title>/etc/shorewall/route_rules</title>
|
|
|
|
|
|
2009-02-28 04:45:43 +01:00
|
|
|
|
<para>The <filename>route_rules</filename> file allows assigning certain
|
|
|
|
|
traffic to a particular provider just as entries in the
|
|
|
|
|
<filename>tcrules</filename> file. The difference between the two files
|
|
|
|
|
is that entries in <filename>route_rules</filename> are independent of
|
|
|
|
|
Netfilter.</para>
|
2006-05-01 23:40:05 +02:00
|
|
|
|
|
2007-06-28 22:20:16 +02:00
|
|
|
|
<section id="Routing_rules">
|
2006-05-01 23:40:05 +02:00
|
|
|
|
<title>Routing Rules</title>
|
|
|
|
|
|
|
|
|
|
<para>Routing rules are maintained by the Linux kernel and can be
|
|
|
|
|
displayed using the <command>ip rule ls</command> command. When
|
|
|
|
|
routing a packet, the rules are processed in turn until the packet is
|
|
|
|
|
successfully routed.</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>gateway:~ # <command>ip rule ls</command>
|
2006-05-02 03:09:57 +02:00
|
|
|
|
0: from all lookup local <=== Local (to the firewall) IP addresses
|
|
|
|
|
10001: from all fwmark 0x1 lookup Blarg <=== This and the next rule are generated by the
|
|
|
|
|
10002: from all fwmark 0x2 lookup Comcast 'MARK' values in /etc/shorewall/providers.
|
|
|
|
|
20000: from 206.124.146.176 lookup Blarg <=== This and the next rule are generated unless
|
|
|
|
|
20256: from 24.12.22.33 lookup Comcast 'loose' is specified; based in the output of 'ip addr ls'
|
|
|
|
|
32766: from all lookup main <=== This is the routing table shown by 'iproute -n'
|
2006-05-06 20:08:48 +02:00
|
|
|
|
32767: from all lookup default <=== This table is usually empty
|
2006-05-01 23:40:05 +02:00
|
|
|
|
gateway:~ #</programlisting>
|
|
|
|
|
|
|
|
|
|
<para>In the above example, there are two providers: Blarg and Comcast
|
|
|
|
|
with MARK 1 going to Blarg and mark 2 going to Comcast.</para>
|
|
|
|
|
</section>
|
|
|
|
|
|
2007-06-28 22:20:16 +02:00
|
|
|
|
<section id="route_rules_columns">
|
2006-05-01 23:40:05 +02:00
|
|
|
|
<title>Columns in the route_rules file</title>
|
|
|
|
|
|
|
|
|
|
<para>Columns in the file are:</para>
|
|
|
|
|
|
|
|
|
|
<variablelist>
|
|
|
|
|
<varlistentry>
|
2006-05-02 03:09:57 +02:00
|
|
|
|
<term>SOURCE (Optional)</term>
|
2006-05-01 23:40:05 +02:00
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>An ip address (network or host) that matches the source IP
|
|
|
|
|
address in a packet. May also be specified as an interface name
|
|
|
|
|
optionally followed by ":" and an address. If the device 'lo' is
|
|
|
|
|
specified, the packet must originate from the firewall
|
|
|
|
|
itself.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
|
|
<varlistentry>
|
2006-05-02 03:09:57 +02:00
|
|
|
|
<term>DEST (Optional)</term>
|
2006-05-01 23:40:05 +02:00
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>An ip address (network or host) that matches the
|
|
|
|
|
destination IP address in a packet.</para>
|
|
|
|
|
|
|
|
|
|
<para>If you choose to omit either SOURCE or DEST, place "-" in
|
|
|
|
|
that column. Note that you may not omit both SOURCE and
|
|
|
|
|
DEST.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
|
<term>PROVIDER</term>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>The provider to route the traffic through. May be
|
|
|
|
|
expressed either as the provider name or the provider
|
|
|
|
|
number.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
|
<term>PRIORITY</term>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>The rule's priority which determines the order in which
|
|
|
|
|
the rules are processed.</para>
|
|
|
|
|
|
|
|
|
|
<para>1000-1999 Before Shorewall-generated 'MARK' rules</para>
|
|
|
|
|
|
|
|
|
|
<para>11000- 11999 After 'MARK' rules but before
|
|
|
|
|
Shorewall-generated rules for ISP interfaces.</para>
|
|
|
|
|
|
|
|
|
|
<para>26000-26999 After ISP interface rules but before 'default'
|
|
|
|
|
rule.</para>
|
|
|
|
|
|
|
|
|
|
<para>Rules with equal priority are applied in the order in
|
|
|
|
|
which they appear in the file.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</varlistentry>
|
|
|
|
|
</variablelist>
|
2007-12-05 21:07:25 +01:00
|
|
|
|
</section>
|
|
|
|
|
|
2009-03-04 18:10:18 +01:00
|
|
|
|
<section>
|
|
|
|
|
<title>Multi-ISP and VPN</title>
|
|
|
|
|
|
|
|
|
|
<para>For those VPN types that use routing to direct traffic to remote
|
|
|
|
|
VPN clients (including but not limited to OpenVPN in routed mode and
|
|
|
|
|
PPTP), the VPN software adds a host route to the <emphasis
|
2009-03-17 20:55:34 +01:00
|
|
|
|
role="bold">main</emphasis> table for each VPN client. The best
|
|
|
|
|
approach is to use USE_DEFAULT_RT=Yes as described <link
|
|
|
|
|
linkend="USE_DEFAULT_RT">below</link>. If that isn't possible, you
|
|
|
|
|
must add a routing rule in the 1000-1999 range to specify the
|
2009-03-04 18:10:18 +01:00
|
|
|
|
<emphasis role="bold">main</emphasis> table for traffic addressed to
|
|
|
|
|
those clients. See<link linkend="Openvpn"> Example 2</link>
|
|
|
|
|
below.</para>
|
2009-03-17 20:55:34 +01:00
|
|
|
|
|
|
|
|
|
<para>If you have an IPSEC gateway on your firewall, be sure to
|
|
|
|
|
arrange for ESP packets to be routed out of the same interface that
|
|
|
|
|
you have configured your keying daemon to use.</para>
|
2009-03-04 18:10:18 +01:00
|
|
|
|
</section>
|
|
|
|
|
|
2007-12-05 21:07:25 +01:00
|
|
|
|
<section id="Examples">
|
|
|
|
|
<title>Examples</title>
|
2006-05-01 23:40:05 +02:00
|
|
|
|
|
2007-12-05 21:07:25 +01:00
|
|
|
|
<para><emphasis role="bold">Example 1:</emphasis> You want all traffic
|
|
|
|
|
entering the firewall on eth1 to be routed through Comcast.</para>
|
2006-05-01 23:40:05 +02:00
|
|
|
|
|
|
|
|
|
<programlisting>#SOURCE DEST PROVIDER PRIORITY
|
|
|
|
|
eth1 - Comcast 1000</programlisting>
|
|
|
|
|
|
|
|
|
|
<para>With this entry, the output of <command>ip rule ls</command>
|
|
|
|
|
would be as follows.</para>
|
|
|
|
|
|
|
|
|
|
<para><programlisting>gateway:~ # <command>ip rule ls</command>
|
|
|
|
|
0: from all lookup local
|
2009-03-18 22:33:05 +01:00
|
|
|
|
<emphasis role="bold">1000: from all iif eth1 lookup Comcast</emphasis>
|
2006-05-01 23:40:05 +02:00
|
|
|
|
10001: from all fwmark 0x1 lookup Blarg
|
|
|
|
|
10002: from all fwmark 0x2 lookup Comcast
|
|
|
|
|
20000: from 206.124.146.176 lookup Blarg
|
|
|
|
|
20256: from 24.12.22.33 lookup Comcast
|
|
|
|
|
32766: from all lookup main
|
|
|
|
|
32767: from all lookup default
|
|
|
|
|
gateway:~ #</programlisting>Note that because we used a priority of 1000, the
|
|
|
|
|
test for <filename class="devicefile">eth1</filename> is inserted
|
|
|
|
|
before the fwmark tests.</para>
|
2006-05-06 20:08:48 +02:00
|
|
|
|
|
2008-07-03 22:52:09 +02:00
|
|
|
|
<para id="Openvpn"><emphasis role="bold">Example 2:</emphasis> You use
|
|
|
|
|
OpenVPN (routed setup w/tunX) in combination with multiple providers.
|
|
|
|
|
In this case you have to set up a rule to ensure that the OpenVPN
|
|
|
|
|
traffic is routed back through the tunX interface(s) rather than
|
2008-08-25 02:36:41 +02:00
|
|
|
|
through any of the providers. 10.8.0.0/24 is the subnet chosen in your
|
|
|
|
|
OpenVPN configuration (server 10.8.0.0 255.255.255.0).</para>
|
2006-05-06 20:08:48 +02:00
|
|
|
|
|
|
|
|
|
<programlisting>#SOURCE DEST PROVIDER PRIORITY
|
|
|
|
|
- 10.8.0.0/24 main 1000</programlisting>
|
2006-05-01 23:40:05 +02:00
|
|
|
|
</section>
|
|
|
|
|
</section>
|
2007-12-10 23:53:20 +01:00
|
|
|
|
|
2008-11-16 16:02:51 +01:00
|
|
|
|
<section id="USE_DEFAULT_RT">
|
|
|
|
|
<title>USE_DEFAULT_RT</title>
|
|
|
|
|
|
2009-02-28 04:45:43 +01:00
|
|
|
|
<para>USE_DEFAULT_RT is an option in <ulink
|
2008-11-16 16:02:51 +01:00
|
|
|
|
url="manpages/shorewall.conf.html">shorewall.conf</ulink> (5).</para>
|
|
|
|
|
|
2009-01-30 23:20:22 +01:00
|
|
|
|
<para>One of the drawbacks of the Multi-ISP support as described in the
|
2008-11-16 16:02:51 +01:00
|
|
|
|
preceding sections is that changes to the main table made by
|
|
|
|
|
applications are not added to the individual provider tables. This makes
|
|
|
|
|
route rules such as described in <link linkend="Openvpn">one of the
|
|
|
|
|
examples above</link> necessary.</para>
|
|
|
|
|
|
|
|
|
|
<para>USE_DEFAULT_RT=Yes works around that problem by passing packets
|
|
|
|
|
through the main table first rather than last. This has a number of
|
|
|
|
|
implications:</para>
|
|
|
|
|
|
|
|
|
|
<orderedlist>
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Both the DUPLICATE and the COPY columns in the providers file
|
|
|
|
|
must remain empty or contain "-". The individual provider routing
|
|
|
|
|
tables generated when USE_DEFAULT_RT=Yes contain only a host route
|
|
|
|
|
to the gateway and a default route via the gateway.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>The <emphasis role="bold">balance</emphasis> option is assumed
|
|
|
|
|
for all interfaces that do not have the <emphasis
|
|
|
|
|
role="bold">loose</emphasis> option. When you want both <emphasis
|
|
|
|
|
role="bold">balance</emphasis> and <emphasis
|
|
|
|
|
role="bold">loose</emphasis>, both must be specified.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>The default route generated by Shorewall is added to the
|
|
|
|
|
<emphasis>default</emphasis> routing table (253) rather than to the
|
|
|
|
|
main routing table (254).</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Packets are sent through the main routing table by a routing
|
|
|
|
|
rule with priority 999. In ), the priority range 1-998 may be used
|
|
|
|
|
for inserting rules that bypass the main table.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>You should disable all default route management outside of
|
|
|
|
|
Shorewall. If a default route is inadvertently added to the main
|
|
|
|
|
table while Shorewall is started, then all policy routing will stop
|
|
|
|
|
working except for those routing rules in the priority range
|
|
|
|
|
1-998.</para>
|
|
|
|
|
</listitem>
|
2009-04-15 01:25:53 +02:00
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>For ppp interfaces, the GATEWAY may remain unspecified ("-").
|
|
|
|
|
For those interfaces managed by dhcpcd or dhclient, you may specify
|
|
|
|
|
'detect' in the GATEWAY column; Shorewall will use the dhcp client's
|
|
|
|
|
database to determine the gateway IP address. All other interfaces
|
|
|
|
|
must have a GATEWAY specified explicitly.</para>
|
|
|
|
|
</listitem>
|
2008-11-16 16:02:51 +01:00
|
|
|
|
</orderedlist>
|
|
|
|
|
|
|
|
|
|
<para>Although 'balance' is automatically assumed when
|
|
|
|
|
USE_DEFAULT_RT=Yes, you can easily cause all traffic to use one provider
|
|
|
|
|
except when you explicitly direct it to use the other provider via
|
|
|
|
|
<ulink
|
|
|
|
|
url="manpages/shorewall-route_rules.html">shorewall-route_rules</ulink>
|
|
|
|
|
(5) or <ulink
|
|
|
|
|
url="manpages/shorewall-tcrules.html">shorewall-tcrules</ulink>
|
|
|
|
|
(5).</para>
|
|
|
|
|
|
|
|
|
|
<para>Example (send all traffic through the 'shorewall' provider unless
|
|
|
|
|
otherwise directed).</para>
|
|
|
|
|
|
|
|
|
|
<para>/etc/shorewall/providers:<programlisting>#NAME NUMBER MARK DUPLICATE INTERFACE GATEWAY OPTIONS
|
|
|
|
|
linksys 1 1 - wlan0 172.20.1.1 track,balance=1,optional
|
|
|
|
|
shorewall 2 2 - eth0 192.168.1.254 track,balance=2,optional</programlisting>/etc/shorewall/route_rules:<programlisting>#SOURCE DEST PROVIDER PRIORITY
|
|
|
|
|
- - shorewall 11999</programlisting></para>
|
|
|
|
|
</section>
|
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<section id="LinkMonitor">
|
2009-01-31 01:18:59 +01:00
|
|
|
|
<title>Gateway Monitoring and Failover</title>
|
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<para>There are a couple of options available for monitoring the status
|
|
|
|
|
of provider links and taking action when a failure occurs.</para>
|
|
|
|
|
|
2009-06-23 20:14:02 +02:00
|
|
|
|
<para>You specify the <option>optional</option> option in
|
|
|
|
|
<filename>/etc/shorewall/interfaces</filename>:</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>#ZONE INTERFACE BROADCAST OPTIONS
|
|
|
|
|
net eth0 detect <emphasis role="bold">optional</emphasis>
|
|
|
|
|
net eth1 detect <emphasis role="bold">optional</emphasis></programlisting>
|
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<section id="swping">
|
|
|
|
|
<title>SWPING</title>
|
|
|
|
|
|
2009-02-28 04:45:43 +01:00
|
|
|
|
<para>Shorewall includes a sample monitoring script
|
|
|
|
|
<filename>swping</filename>. The <filename>swping</filename> file is
|
|
|
|
|
available in the main directory contained in the Shorewall-common
|
|
|
|
|
tarball and is included in the Shorewall-common documentation
|
2009-05-20 16:54:17 +02:00
|
|
|
|
directory in the Shorewall-common RPM. The script is inspired by
|
2009-02-28 04:45:43 +01:00
|
|
|
|
Angsuman Chakraborty's <ulink
|
2009-02-24 17:44:06 +01:00
|
|
|
|
url="http://blog.taragana.com/index.php/archive/how-to-load-balancing-failover-with-dual-multi-wan-adsl-cable-connections-on-linux/">gwping</ulink>
|
|
|
|
|
script.</para>
|
|
|
|
|
|
|
|
|
|
<important>
|
|
|
|
|
<para>These samples are offered <emphasis>as is</emphasis> — they
|
|
|
|
|
work for me but I don't make any claim that they will work for
|
|
|
|
|
anyone else. But if you have a need for automated link monitoring,
|
|
|
|
|
they offer you a place to start.</para>
|
|
|
|
|
</important>
|
|
|
|
|
|
|
|
|
|
<para>The script should be copied to a directory on root's PATH such
|
|
|
|
|
as <filename>/usr/local/sbin/</filename>.</para>
|
|
|
|
|
|
|
|
|
|
<para>The script works by sending pings to <emphasis>target</emphasis>
|
|
|
|
|
IP addresses through each external interface. These targets must not
|
|
|
|
|
depend on any routes other than those that are present in the main
|
|
|
|
|
routing table. That ensures that a route is available to the target
|
|
|
|
|
even when the target's interface is not working and Shorewall has
|
|
|
|
|
omitted it from the routing configuration. An interface is assumed to
|
|
|
|
|
be <firstterm>up</firstterm> when a specified number (UP_COUNT) of
|
|
|
|
|
consecutive ping operations succeed. Similarly, an interface is
|
|
|
|
|
assumed to be <firstterm>down</firstterm> when a specified number
|
|
|
|
|
(DOWN_COUNT) of consecutive ping operations fail. You can specify the
|
|
|
|
|
interval between pings (PING_INTERVAL).</para>
|
|
|
|
|
|
|
|
|
|
<para>The script monitors two interfaces but it is a trivial exercise
|
|
|
|
|
to extend it to more than two. At the top are a number of variables to
|
|
|
|
|
set:</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>#
|
2009-01-31 01:18:59 +01:00
|
|
|
|
# IP family -- 4 or 6
|
|
|
|
|
#
|
|
|
|
|
FAMILY=4
|
|
|
|
|
#
|
2009-02-01 19:35:06 +01:00
|
|
|
|
# The commands to run when the status of a line changes. Multiple commands may be specified
|
|
|
|
|
# when separated by semicolons (";")
|
2009-01-31 01:18:59 +01:00
|
|
|
|
#
|
2009-02-01 19:35:06 +01:00
|
|
|
|
COMMAND=
|
|
|
|
|
|
2009-01-31 01:18:59 +01:00
|
|
|
|
...
|
|
|
|
|
#
|
|
|
|
|
# Interfaces to monitor -- you may use shell variables from your params file
|
|
|
|
|
#
|
|
|
|
|
IF1=eth0
|
|
|
|
|
IF2=eth1
|
|
|
|
|
#
|
2009-01-31 18:27:24 +01:00
|
|
|
|
# Sites to Ping. Must depend only on routes in the 'main' routing table. If not specified,
|
|
|
|
|
# the interface is assumed to be managed by dhcpcd and the script uses the gateway address
|
|
|
|
|
# from /var/lib/dhcpcd/dhcpcd-${IFx}.info
|
2009-01-31 01:18:59 +01:00
|
|
|
|
#
|
|
|
|
|
TARGET1=
|
|
|
|
|
TARGET2=
|
|
|
|
|
#
|
|
|
|
|
# How often to ping
|
|
|
|
|
#
|
|
|
|
|
PING_INTERVAL=5
|
|
|
|
|
#
|
|
|
|
|
# Value for ping's -W option
|
|
|
|
|
#
|
|
|
|
|
PING_TIMEOUT=2
|
|
|
|
|
#
|
|
|
|
|
# This many successive pings must succeed for the interface to be marked up when it is down
|
|
|
|
|
#
|
|
|
|
|
UP_COUNT=5
|
|
|
|
|
#
|
|
|
|
|
# This many successive pings must fail for the interface to be marked down when it is up
|
|
|
|
|
#
|
|
|
|
|
DOWN_COUNT=2</programlisting>
|
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<para>If you leave COMMAND empty, the script sets its value
|
|
|
|
|
automatically depending on whether Shorewall-lite is installed.</para>
|
2009-01-31 01:18:59 +01:00
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<para>When the status of an interface changes:</para>
|
2009-01-31 01:18:59 +01:00
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<itemizedlist>
|
|
|
|
|
<listitem>
|
2009-05-20 16:54:17 +02:00
|
|
|
|
<para>For each interface, a file is placed in ${VARDIR} (normally
|
|
|
|
|
/var/lib/shorewall) to record the status of the interface: either
|
|
|
|
|
0 (UP) or 1 (DOWN). The name of the file is
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<filename><replaceable>interface</replaceable>.status</filename>
|
|
|
|
|
where <replaceable>interface</replaceable> is the interface (e.g.,
|
|
|
|
|
<filename>eth0.status</filename>).</para>
|
|
|
|
|
</listitem>
|
2009-01-31 01:18:59 +01:00
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<listitem>
|
|
|
|
|
<para>A <command>shorewall -f restart</command> command is
|
|
|
|
|
executed (<command>shorewall-lite restart</command>, if
|
|
|
|
|
Shorewall-lite is installed).</para>
|
|
|
|
|
</listitem>
|
2009-01-31 01:18:59 +01:00
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<listitem>
|
|
|
|
|
<para>The contents of the main routing table are displayed.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</itemizedlist>
|
2009-01-31 01:18:59 +01:00
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<para>The .status files are intended to be used with the following
|
|
|
|
|
<filename>/etc/shorewall/isusable</filename> script.<programlisting>local status=0
|
2009-01-31 01:18:59 +01:00
|
|
|
|
|
2009-05-20 16:54:17 +02:00
|
|
|
|
[ -f ${VARDIR}/${1}.status ] && status=$(cat ${VARDIR}/${1}.status)
|
2009-01-31 01:18:59 +01:00
|
|
|
|
|
|
|
|
|
return $status</programlisting></para>
|
|
|
|
|
|
2009-05-20 16:54:17 +02:00
|
|
|
|
<para>The above script is installed in <filename
|
|
|
|
|
class="directory">/etc/shorewall</filename>, beginning with Shorewall
|
|
|
|
|
4.3.11.</para>
|
2009-01-31 01:18:59 +01:00
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<para>Also included is a sample init script
|
|
|
|
|
(<filename>swping.init</filename>) to start the monitoring daemon.
|
|
|
|
|
Copy it to<filename> /etc/init.d/swping</filename> and use your
|
|
|
|
|
distribution's SysV init tools to cause it to be run at boot. It works
|
|
|
|
|
on <trademark>OpenSuSE</trademark> 11.0 -- YMMV. Modify the PROG and
|
|
|
|
|
STATEDIR variables as needed.</para>
|
2009-01-31 01:18:59 +01:00
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<para>As an alternative to using the init script, you can add the
|
|
|
|
|
following to <filename>/etc/shorewall/started</filename>:</para>
|
2009-01-31 01:18:59 +01:00
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<programlisting>if [ "$COMMAND" = start ]; then
|
2009-01-31 01:18:59 +01:00
|
|
|
|
killall -9 swping 2> /dev/null #be sure that there are none left running
|
|
|
|
|
/usr/local/sbin/swping &
|
|
|
|
|
fi</programlisting>
|
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<para>and add this to
|
|
|
|
|
<filename>/etc/shorewall/stopped</filename>.</para>
|
2009-01-31 01:18:59 +01:00
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<para><programlisting>if [ "$COMMAND" = stop -o "$COMMAND" = clear ]; then
|
2009-01-31 01:18:59 +01:00
|
|
|
|
killall -9 swping 2> /dev/null
|
|
|
|
|
fi</programlisting></para>
|
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<para>This simple script has a number of limitations:</para>
|
2009-01-31 01:18:59 +01:00
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<orderedlist>
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>It only works on IPv4 or IPv6 but not both at once. So if
|
|
|
|
|
you want to monitor both IPv4 and IPv6, you need to clone the
|
|
|
|
|
script are run two copies; one for IPv4 and one for IPv6.</para>
|
|
|
|
|
</listitem>
|
2009-01-31 01:18:59 +01:00
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<listitem>
|
|
|
|
|
<para>It can only detect the gateway for interfaces managed by
|
|
|
|
|
dhcpcd.</para>
|
|
|
|
|
</listitem>
|
2009-02-01 19:35:06 +01:00
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<listitem>
|
|
|
|
|
<para>It's method of determining whether an interface is up or
|
|
|
|
|
down is crude. You will normally specify the default gateway for
|
|
|
|
|
each provider as the sites to ping and being able to ping the
|
|
|
|
|
default gateway is not a surefire indication that the provider is
|
|
|
|
|
usable. The method of determining whether a site is up or down is
|
|
|
|
|
also crude.</para>
|
|
|
|
|
</listitem>
|
2009-01-31 01:18:59 +01:00
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<listitem>
|
|
|
|
|
<para>Because of the crudeness of the algorithm, hysteresis may
|
|
|
|
|
occur.</para>
|
|
|
|
|
</listitem>
|
2009-01-31 01:18:59 +01:00
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<listitem>
|
|
|
|
|
<para>It is tricky to configure a system such that the system
|
|
|
|
|
works correctly when one of its providers is down unless you
|
|
|
|
|
largely don't care which interface is used.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</orderedlist>
|
|
|
|
|
</section>
|
|
|
|
|
|
|
|
|
|
<section id="lsm">
|
|
|
|
|
<title>Link Status Monitor (LSM)</title>
|
|
|
|
|
|
|
|
|
|
<para><ulink url="http://lsm.foobar.fi/">Link Status Monitor</ulink>
|
|
|
|
|
was written by Mika Ilmaranta <ilmis at nullnet.fi> and performs
|
|
|
|
|
more sophisticated monitoring than the simple swping script described
|
|
|
|
|
in the preceding section.</para>
|
|
|
|
|
|
2009-05-20 16:54:17 +02:00
|
|
|
|
<para>Like many Open Source products, LSM is poorly documented. It's
|
2009-06-19 22:00:58 +02:00
|
|
|
|
main configuration file is normally kept in
|
|
|
|
|
<filename>/etc/lsm/lsm.conf</filename>, but the file's name is passed
|
|
|
|
|
as an argument to the lsm program so you can name it anything you
|
|
|
|
|
want.</para>
|
2009-05-20 16:54:17 +02:00
|
|
|
|
|
|
|
|
|
<para>The sample <filename>lsm.conf</filename> included with the
|
|
|
|
|
product shows some of the possibilities for configuration. One feature
|
|
|
|
|
that is not mentioned in the sample is that an "include" directive is
|
|
|
|
|
supported. This allows additional files to be sourced in from the main
|
|
|
|
|
configuration file.</para>
|
|
|
|
|
|
2009-02-24 17:57:33 +01:00
|
|
|
|
<para>I personally use LSM here at shorewall.net (configuration is
|
2009-06-19 22:00:58 +02:00
|
|
|
|
described <link linkend="Complete">below</link>). I have set things up
|
|
|
|
|
so that Shorewall [re]starts lsm during processing of the
|
|
|
|
|
<command>start</command> and <command>restore</command> commands. I
|
|
|
|
|
don't have Shorewall restart lsm during Shorewall
|
|
|
|
|
<command>restart</command> because I restart Shorewall much more often
|
|
|
|
|
than the average user is likely to do. I have Shorewall start lsm
|
|
|
|
|
because I have a dynamic IP address from one of my providers
|
|
|
|
|
(Comcast); Shorewall detects the default gateway to that provider and
|
|
|
|
|
creates a secondary configuration file
|
|
|
|
|
(<filename>/etc/lsm/shorewall.conf</filename>) that contains the link
|
|
|
|
|
configurations. That file is included by
|
2009-08-25 21:59:25 +02:00
|
|
|
|
<filename>/etc/lsm/lsm.conf</filename>.</para>
|
2009-06-19 22:00:58 +02:00
|
|
|
|
|
2009-06-19 22:05:35 +02:00
|
|
|
|
<para>Below are my relevant configuration files.</para>
|
|
|
|
|
|
|
|
|
|
<warning>
|
2009-06-20 18:35:08 +02:00
|
|
|
|
<para>These files only work with Shorewall-perl 4.4 Beta 2 and
|
2009-06-19 22:05:35 +02:00
|
|
|
|
later.</para>
|
|
|
|
|
</warning>
|
2009-02-24 17:44:06 +01:00
|
|
|
|
|
|
|
|
|
<para><filename>/etc/shorewall/isusable</filename>:</para>
|
|
|
|
|
|
2009-06-19 23:39:45 +02:00
|
|
|
|
<para>Note that <filename>/etc/lsm/script </filename>writes
|
|
|
|
|
a<filename> ${VARDIR}/xxx.status</filename> file when the status of an
|
2009-06-20 18:35:08 +02:00
|
|
|
|
interface changes.</para>
|
2009-06-19 23:39:45 +02:00
|
|
|
|
|
2009-05-20 16:54:17 +02:00
|
|
|
|
<programlisting>local status=0
|
2009-02-24 17:44:06 +01:00
|
|
|
|
|
2009-05-20 16:54:17 +02:00
|
|
|
|
[ -f ${VARDIR}/${1}.status ] && status=$(cat ${VARDIR}/${1}.status)
|
2009-02-24 17:44:06 +01:00
|
|
|
|
|
|
|
|
|
return $status</programlisting>
|
|
|
|
|
|
2009-06-20 18:35:08 +02:00
|
|
|
|
<para><filename>/etc/shorewall/lib.private</filename>:</para>
|
2009-02-24 17:44:06 +01:00
|
|
|
|
|
|
|
|
|
<programlisting>###############################################################################
|
2009-06-20 18:35:08 +02:00
|
|
|
|
# Create /etc/lsm/shorewall.conf
|
|
|
|
|
# Remove the current interface status files
|
|
|
|
|
# Start lsm
|
2009-02-24 17:44:06 +01:00
|
|
|
|
###############################################################################
|
2009-06-20 18:35:08 +02:00
|
|
|
|
start_lsm() {
|
2009-05-20 16:54:17 +02:00
|
|
|
|
killall lsm 2> /dev/null
|
2009-02-24 17:44:06 +01:00
|
|
|
|
cat <<EOF > /etc/lsm/shorewall.conf
|
|
|
|
|
connection {
|
|
|
|
|
name=Avvanta
|
|
|
|
|
checkip=206.124.146.254
|
2009-06-20 18:35:08 +02:00
|
|
|
|
device=$EXT_IF
|
2009-02-24 17:44:06 +01:00
|
|
|
|
ttl=2
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
connection {
|
|
|
|
|
name=Comcast
|
2009-06-20 18:35:08 +02:00
|
|
|
|
checkip=${ETH0_GATEWAY:-71.231.152.1}
|
|
|
|
|
device=$COM_IF
|
2009-02-24 17:44:06 +01:00
|
|
|
|
ttl=1
|
|
|
|
|
}
|
|
|
|
|
EOF
|
2009-06-20 18:35:08 +02:00
|
|
|
|
rm -f /etc/shorewall/*.status
|
2009-02-24 17:44:06 +01:00
|
|
|
|
/usr/sbin/lsm /etc/lsm/lsm.conf >> /var/log/lsm
|
2009-06-20 18:35:08 +02:00
|
|
|
|
}</programlisting>
|
2009-02-24 17:44:06 +01:00
|
|
|
|
|
|
|
|
|
<para>eth3 has a dynamic IP address so I need to use the
|
2009-06-19 23:39:45 +02:00
|
|
|
|
Shorewall-detected gateway address ($ETH3_GATEWAY). I supply a default
|
|
|
|
|
value in the event that detection fails.</para>
|
2009-02-24 17:44:06 +01:00
|
|
|
|
|
2009-06-20 18:35:08 +02:00
|
|
|
|
<para><filename>/etc/shorewall/started</filename>:</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>##################################################################################
|
|
|
|
|
# [re]start lsm if this is a 'start' command or if lsm isn't running
|
|
|
|
|
##################################################################################
|
|
|
|
|
if [ "$COMMAND" = start -o -z "$(ps ax | grep 'lsm ' | grep -v 'grep ' )" ]; then
|
|
|
|
|
start_lsm
|
|
|
|
|
fi</programlisting>
|
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
<para><filename>/etc/shorewall/restored</filename>:</para>
|
|
|
|
|
|
2009-06-20 18:35:08 +02:00
|
|
|
|
<programlisting>##################################################################################
|
|
|
|
|
# Start lsm if it isn't running
|
|
|
|
|
##################################################################################
|
|
|
|
|
if [ -z "$(ps ax | grep 'lsm ' | grep -v 'grep ' )" ]; then
|
|
|
|
|
start_lsm
|
2009-02-24 17:44:06 +01:00
|
|
|
|
fi</programlisting>
|
|
|
|
|
|
|
|
|
|
<para><filename>/etc/lsm/lsm.conf</filename>:</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>#
|
|
|
|
|
# Defaults for the connection entries
|
|
|
|
|
#
|
|
|
|
|
defaults {
|
|
|
|
|
name=defaults
|
|
|
|
|
checkip=127.0.0.1
|
|
|
|
|
eventscript=/etc/lsm/script
|
|
|
|
|
max_packet_loss=20
|
|
|
|
|
max_successive_pkts_lost=7
|
|
|
|
|
min_packet_loss=5
|
|
|
|
|
min_successive_pkts_rcvd=10
|
|
|
|
|
interval_ms=2000
|
|
|
|
|
timeout_ms=2000
|
|
|
|
|
warn_email=teastep@shorewall.net
|
|
|
|
|
check_arp=0
|
|
|
|
|
sourceip=
|
|
|
|
|
ttl=64
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
include /etc/lsm/shorewall.conf</programlisting>
|
|
|
|
|
|
|
|
|
|
<para><filename>/etc/lsm/script</filename><programlisting>#!/bin/sh
|
|
|
|
|
#
|
|
|
|
|
# (C) 2009 Mika Ilmaranta <ilmis@nullnet.fi>
|
|
|
|
|
# (C) 2009 Tom Eastep <teastep@shorewall.net>
|
|
|
|
|
#
|
|
|
|
|
# License: GPLv2
|
|
|
|
|
#
|
|
|
|
|
|
|
|
|
|
STATE=${1}
|
|
|
|
|
NAME=${2}
|
|
|
|
|
CHECKIP=${3}
|
|
|
|
|
DEVICE=${4}
|
|
|
|
|
WARN_EMAIL=${5}
|
|
|
|
|
REPLIED=${6}
|
|
|
|
|
WAITING=${7}
|
|
|
|
|
TIMEOUT=${8}
|
|
|
|
|
REPLY_LATE=${9}
|
|
|
|
|
CONS_RCVD=${10}
|
|
|
|
|
CONS_WAIT=${11}
|
|
|
|
|
CONS_MISS=${12}
|
|
|
|
|
AVG_RTT=${13}
|
|
|
|
|
|
2009-05-20 16:54:17 +02:00
|
|
|
|
if [ -f /usr/share/shorewall-lite/lib.base ]; then
|
|
|
|
|
VARDIR=/var/lib/shorewall-lite
|
|
|
|
|
STATEDIR=/etc/shorewall-lite
|
|
|
|
|
else
|
|
|
|
|
VARDIR=/var/lib/shorewall
|
|
|
|
|
STATEDIR=/etc/shorewall
|
|
|
|
|
fi
|
|
|
|
|
|
|
|
|
|
[ -f ${STATEDIR}/vardir ] && . ${STATEDIR}/vardir
|
|
|
|
|
|
2009-02-24 17:44:06 +01:00
|
|
|
|
cat <<EOM | mail -s "${NAME} ${STATE}, DEV ${DEVICE}" ${WARN_EMAIL}
|
|
|
|
|
|
|
|
|
|
Hi,
|
|
|
|
|
|
|
|
|
|
Connection ${NAME} is now ${STATE}.
|
|
|
|
|
|
|
|
|
|
Following parameters were passed:
|
|
|
|
|
newstate = ${STATE}
|
|
|
|
|
name = ${NAME}
|
|
|
|
|
checkip = ${CHECKIP}
|
|
|
|
|
device = ${DEVICE}
|
|
|
|
|
warn_email = ${WARN_EMAIL}
|
|
|
|
|
|
|
|
|
|
Packet counters:
|
|
|
|
|
replied = ${REPLIED} packets replied
|
|
|
|
|
waiting = ${WAITING} packets waiting for reply
|
|
|
|
|
timeout = ${TIMEOUT} packets that have timed out (= packet loss)
|
|
|
|
|
reply_late = ${REPLY_LATE} packets that received a reply after timeout
|
|
|
|
|
cons_rcvd = ${CONS_RCVD} consecutively received replies in sequence
|
|
|
|
|
cons_wait = ${CONS_WAIT} consecutive packets waiting for reply
|
|
|
|
|
cons_miss = ${CONS_MISS} consecutive packets that have timed out
|
|
|
|
|
avg_rtt = ${AVG_RTT} average rtt, notice that waiting and timed out packets have rtt = 0 when calculating this
|
|
|
|
|
|
|
|
|
|
Your LSM Daemon
|
|
|
|
|
|
|
|
|
|
EOM
|
|
|
|
|
|
|
|
|
|
[ ${STATE} = up ] && state=0 || state=1
|
|
|
|
|
|
2009-05-20 16:54:17 +02:00
|
|
|
|
echo $state > ${VARDIR}/${DEVICE}.status
|
2009-02-24 17:44:06 +01:00
|
|
|
|
|
|
|
|
|
/sbin/shorewall -f restart >> /var/log/lsm 2>&1
|
|
|
|
|
|
|
|
|
|
/sbin/shorewall show routing >> /var/log/lsm
|
|
|
|
|
|
|
|
|
|
exit 0;
|
|
|
|
|
|
|
|
|
|
#EOF</programlisting>:</para>
|
|
|
|
|
</section>
|
2009-01-31 01:18:59 +01:00
|
|
|
|
</section>
|
|
|
|
|
|
2007-12-10 23:53:20 +01:00
|
|
|
|
<section id="Shared">
|
|
|
|
|
<title>Two Providers Sharing an Interface</title>
|
|
|
|
|
|
2009-05-20 16:54:17 +02:00
|
|
|
|
<para>Shared interface support has the following characteristics:</para>
|
2007-12-10 23:53:20 +01:00
|
|
|
|
|
|
|
|
|
<orderedlist numeration="loweralpha">
|
|
|
|
|
<listitem>
|
2008-08-15 03:26:15 +02:00
|
|
|
|
<para>Only Ethernet (or Ethernet-like) interfaces can be used. For
|
2008-01-12 02:32:18 +01:00
|
|
|
|
inbound traffic, the MAC addresses of the gateway routers are used
|
|
|
|
|
to determine which provider a packet was received through. Note that
|
2007-12-10 23:53:20 +01:00
|
|
|
|
only routed traffic can be categorized using this technique.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>You must specify the address on the interface that corresponds
|
|
|
|
|
to a particular provider in the INTERFACE column by following the
|
|
|
|
|
interface name with a colon (":") and the address.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Entries in <filename>/etc/shorewall/masq</filename> must be
|
|
|
|
|
qualified by the provider name (or number).</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>This feature requires Realm Match support in your kernel and
|
|
|
|
|
iptables.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>You must add route_rules entries for networks that are
|
|
|
|
|
accessed through a particular provider.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>If you have additional IP addresses through either provider,
|
|
|
|
|
you must add <filename>route_rules</filename> to direct traffic FROM
|
|
|
|
|
each of those addresses through the appropriate provider.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>You must manually add MARK rules for traffic known to come
|
|
|
|
|
from each provider.</para>
|
|
|
|
|
</listitem>
|
2008-09-08 17:40:53 +02:00
|
|
|
|
|
|
|
|
|
<listitem>
|
2008-09-08 19:09:31 +02:00
|
|
|
|
<para>You must specify a gateway IP address in the GATEWAY column
|
|
|
|
|
of<filename> /etc/shorewall/providers</filename>; <emphasis
|
|
|
|
|
role="bold">detect</emphasis> is not permitted.</para>
|
2008-09-08 17:40:53 +02:00
|
|
|
|
</listitem>
|
2007-12-10 23:53:20 +01:00
|
|
|
|
</orderedlist>
|
|
|
|
|
|
2008-09-08 17:40:53 +02:00
|
|
|
|
<para>Taken together, b. and h. effectively preclude using this
|
|
|
|
|
technique with dynamic IP addresses.</para>
|
|
|
|
|
|
2007-12-10 23:53:20 +01:00
|
|
|
|
<para>Example:</para>
|
|
|
|
|
|
2009-01-30 23:20:22 +01:00
|
|
|
|
<para>This is our home network circa fall 2008. We have two Internet
|
2008-09-06 21:33:59 +02:00
|
|
|
|
providers:</para>
|
|
|
|
|
|
|
|
|
|
<orderedlist>
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Comcast -- Cable modem with one dynamic IP address.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Avvanta -- ADSL with 5 static IP addresses.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</orderedlist>
|
|
|
|
|
|
2008-09-08 00:51:04 +02:00
|
|
|
|
<para>Because the old <trademark>Compaq</trademark>
|
|
|
|
|
<trademark>Presario</trademark> that I use for a firewall only has three
|
|
|
|
|
PCI slots and no onboard Ethernet, it doesn't have enough Ethernet
|
2008-09-06 21:33:59 +02:00
|
|
|
|
controllers to support both providers. So I use a Linksys WRT300n pre-N
|
2008-09-09 17:19:43 +02:00
|
|
|
|
router as a gateway to Comcast. Note that because the Comcast IP address
|
|
|
|
|
is dynamic, I could not share a single firewall interface between the
|
|
|
|
|
two providers directly.</para>
|
2008-09-06 21:33:59 +02:00
|
|
|
|
|
|
|
|
|
<para>On my personal laptop (ursa), I have 9 virtual machines running
|
|
|
|
|
various Linux distributions. <emphasis>It is the Shorewall configuration
|
|
|
|
|
on ursa that I will describe here</emphasis>.</para>
|
|
|
|
|
|
|
|
|
|
<para>Below is a diagram of our network:<graphic align="center"
|
|
|
|
|
fileref="images/Network2008a.png" /></para>
|
|
|
|
|
|
2008-09-07 19:39:41 +02:00
|
|
|
|
<para>The local wired network in my office is connected to both gateways
|
|
|
|
|
and uses the private (RFC 1918) network 172.20.1.0/24. The Comcast
|
|
|
|
|
gateway has local IP address 172.20.1.1 while the Avvanta gateway has
|
2008-11-16 16:02:51 +01:00
|
|
|
|
local IP address 172.20.1.254. Ursa's eth0 interface has a single IP
|
2008-09-07 19:39:41 +02:00
|
|
|
|
address (172.20.1.130).</para>
|
2008-09-06 21:33:59 +02:00
|
|
|
|
|
|
|
|
|
<para>This configuration uses USE_DEFAULT_RT=Yes in
|
|
|
|
|
<filename>shorewall.conf </filename>(see <link
|
2008-11-16 16:02:51 +01:00
|
|
|
|
linkend="USE_DEFAULT_RT">above</link>).</para>
|
2008-09-06 21:33:59 +02:00
|
|
|
|
|
2008-09-08 00:51:04 +02:00
|
|
|
|
<para>Here is the <filename>providers</filename> file:</para>
|
2008-09-06 21:33:59 +02:00
|
|
|
|
|
2008-09-08 01:48:35 +02:00
|
|
|
|
<programlisting>#NAME NUMBER MARK DUPLICATE INTERFACE GATEWAY OPTIONS COPY
|
|
|
|
|
comcast 1 1 - eth0:172.20.1.130 172.20.1.1 track,loose,balance,optional
|
|
|
|
|
avvanta 2 2 - eth0:172.20.1.130 172.20.1.254 track,optional,loose
|
|
|
|
|
wireless 3 3 - wlan0 172.20.1.1 track,optional</programlisting>
|
|
|
|
|
|
2008-09-06 21:33:59 +02:00
|
|
|
|
<para>Several things to note:</para>
|
|
|
|
|
|
|
|
|
|
<orderedlist>
|
|
|
|
|
<listitem>
|
2008-09-08 19:09:31 +02:00
|
|
|
|
<para>172.20.1.130 is specified as the <filename
|
|
|
|
|
class="devicefile">eth0</filename> IP address for both
|
2008-09-06 21:33:59 +02:00
|
|
|
|
providers.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
2008-09-08 19:09:31 +02:00
|
|
|
|
<para>Both wired providers have the <emphasis
|
|
|
|
|
role="bold">loose</emphasis> option. This prevents Shorewall from
|
|
|
|
|
automatically generating routing rules based on the source IP
|
|
|
|
|
address.</para>
|
2008-09-06 21:33:59 +02:00
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Only <emphasis role="bold">comcast</emphasis> has the
|
|
|
|
|
<emphasis role="bold">balance</emphasis> option. With
|
|
|
|
|
USE_DEFAULT_RT=yes, that means that <emphasis
|
|
|
|
|
role="bold">comcast</emphasis> will be the default provider. While
|
|
|
|
|
<emphasis role="bold">balance</emphasis> is the default, with
|
|
|
|
|
USE_DEFAULT_RT=Yes, it must be specified explicitly when <emphasis
|
|
|
|
|
role="bold">loose</emphasis> is also specified.</para>
|
|
|
|
|
</listitem>
|
2008-09-08 19:09:31 +02:00
|
|
|
|
|
|
|
|
|
<listitem>
|
2008-11-16 16:02:51 +01:00
|
|
|
|
<para>I always disable the <emphasis role="bold">wireless</emphasis>
|
|
|
|
|
interface when the laptop is connected to the wired network.</para>
|
2008-09-08 19:09:31 +02:00
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>I use a different Shorewall configuration when I take the
|
|
|
|
|
laptop on the road.</para>
|
|
|
|
|
</listitem>
|
2008-09-06 21:33:59 +02:00
|
|
|
|
</orderedlist>
|
|
|
|
|
|
|
|
|
|
<para>Here is the route_rules file:<programlisting>#SOURCE DEST PROVIDER PRIORITY
|
|
|
|
|
- 206.124.146.176/31 avvanta 1000
|
|
|
|
|
- 206.124.146.178/31 avvanta 1000
|
|
|
|
|
- 206.124.146.180/32 avvanta 1000</programlisting></para>
|
|
|
|
|
|
|
|
|
|
<para>Those rules direct traffic to the five static Avvanta IP addresses
|
2008-09-08 19:09:31 +02:00
|
|
|
|
(only two are currently used) through the <emphasis
|
|
|
|
|
role="bold">avvanta</emphasis> provider.</para>
|
2008-09-06 21:33:59 +02:00
|
|
|
|
|
|
|
|
|
<para>Here is the tcrules file (MARK_IN_FORWARD_CHAIN=No in
|
|
|
|
|
<filename>shorewall.conf</filename>):<programlisting>#MARK SOURCE DEST PROTO PORT(S) CLIENT USER TEST LENGTH TOS CONNBYTES HELPER
|
|
|
|
|
# PORT(S)
|
|
|
|
|
2 $FW 0.0.0.0/0 tcp 21
|
|
|
|
|
2 $FW 0.0.0.0/0 tcp - - - - - - - ftp
|
|
|
|
|
2 $FW 0.0.0.0/0 tcp 119</programlisting></para>
|
|
|
|
|
|
|
|
|
|
<para>These rules:</para>
|
|
|
|
|
|
|
|
|
|
<itemizedlist>
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Use <emphasis role="bold">avvanta</emphasis> for FTP.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Use <emphasis role="bold">avvanta</emphasis> for NTTP</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</itemizedlist>
|
|
|
|
|
|
|
|
|
|
<para>The remaining files are for a rather standard two-interface config
|
|
|
|
|
with a bridge as the local interface.</para>
|
|
|
|
|
|
|
|
|
|
<para><filename>zones</filename>:<programlisting>#ZONE IPSEC OPTIONS IN OUT
|
|
|
|
|
# ONLY OPTIONS OPTIONS
|
|
|
|
|
fw firewall
|
|
|
|
|
net ipv4
|
|
|
|
|
kvm ipv4</programlisting><filename>policy</filename>:<programlisting>net net NONE
|
|
|
|
|
fw net ACCEPT
|
|
|
|
|
fw kvm ACCEPT
|
|
|
|
|
kvm all ACCEPT
|
|
|
|
|
net all DROP info
|
|
|
|
|
all all REJECT info</programlisting></para>
|
|
|
|
|
|
|
|
|
|
<para>interfaces:<programlisting>#ZONE INTERFACE BROADCAST OPTIONS GATEWAY
|
|
|
|
|
#
|
|
|
|
|
net eth0 detect dhcp,tcpflags,routefilter,blacklist,logmartians,optional,arp_ignore
|
|
|
|
|
net wlan0 detect dhcp,tcpflags,routefilter,blacklist,logmartians,optional
|
|
|
|
|
kvm br0 detect routeback #Virtual Machines</programlisting><note>
|
2008-09-08 19:09:31 +02:00
|
|
|
|
<para><filename class="devicefile">wlan0</filename> is the wireless
|
|
|
|
|
adapter in the notebook. Used when the laptop is in our home but not
|
|
|
|
|
connected to the wired network.</para>
|
2008-08-25 03:27:28 +02:00
|
|
|
|
</note></para>
|
2008-08-25 02:36:41 +02:00
|
|
|
|
|
2008-09-06 21:33:59 +02:00
|
|
|
|
<para>masq:<programlisting>#INTERFACE SUBNET ADDRESS PROTO PORT(S) IPSEC
|
|
|
|
|
eth0 192.168.0.0/24
|
2008-09-08 19:09:31 +02:00
|
|
|
|
wlan0 192.168.0.0/24</programlisting><note>
|
|
|
|
|
<para>Because the firewall has only a single external IP address, I
|
|
|
|
|
don't need to specify the providers in the masq rules.</para>
|
|
|
|
|
</note></para>
|
2007-12-10 23:53:20 +01:00
|
|
|
|
</section>
|
2008-07-03 22:52:09 +02:00
|
|
|
|
</section>
|
2009-01-06 00:40:56 +01:00
|
|
|
|
|
2009-01-06 19:33:19 +01:00
|
|
|
|
<section id="Complete">
|
2009-01-06 00:40:56 +01:00
|
|
|
|
<title>A Complete Working Example</title>
|
|
|
|
|
|
|
|
|
|
<para>This section describes the network at shorewall.net early in 2009.
|
|
|
|
|
The configuration is as follows:</para>
|
|
|
|
|
|
|
|
|
|
<itemizedlist>
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Two providers:</para>
|
|
|
|
|
|
|
|
|
|
<itemizedlist>
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Avvanta -- A slow (1.5mb/384kb) DSL service with 5 static IP
|
|
|
|
|
addresses.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Comcast -- A fast (20mb/10mb) Cable circuit with a single
|
|
|
|
|
<emphasis>dynamic</emphasis> address.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</itemizedlist>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>A local network consisting of wired and wireless client systems.
|
|
|
|
|
A Linksys WRT300N wireless router is used as an access point for the
|
2009-01-10 04:43:26 +01:00
|
|
|
|
wireless hosts.</para>
|
2009-01-06 00:40:56 +01:00
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>A DMZ hosting a single server (lists.shorewall.net aka
|
|
|
|
|
www1.shorewall.net, ftp1.shorewall.net,etc.)</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</itemizedlist>
|
|
|
|
|
|
|
|
|
|
<para>The network is pictured in the following diagram:</para>
|
|
|
|
|
|
|
|
|
|
<graphic align="center" fileref="images/Network2009.png" />
|
|
|
|
|
|
|
|
|
|
<para>Because of the speed of the cable provider, all traffic uses that
|
|
|
|
|
provider unless there is a specific need for the traffic to use the DSL
|
2009-01-06 19:33:19 +01:00
|
|
|
|
line.</para>
|
|
|
|
|
|
|
|
|
|
<itemizedlist>
|
|
|
|
|
<listitem>
|
|
|
|
|
<para>Responses to connections from the Internet to one of the DSL IP
|
|
|
|
|
addresses -- the <emphasis role="bold">track</emphasis> option takes
|
|
|
|
|
care of that.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
|
|
|
|
|
<listitem>
|
2009-01-07 17:25:14 +01:00
|
|
|
|
<para>Connections initiated by the server and connections requested by
|
2009-01-06 19:33:19 +01:00
|
|
|
|
clients on the firewall that have bound their local socket to one of
|
|
|
|
|
the DSL IP addresses. Two entries in
|
|
|
|
|
<filename>/etc/shorewall/route_rules</filename> take care of that
|
|
|
|
|
traffic.</para>
|
|
|
|
|
</listitem>
|
|
|
|
|
</itemizedlist>
|
|
|
|
|
|
|
|
|
|
<para>As a consequence, I have disabled all route filtering on the
|
2009-01-30 23:20:22 +01:00
|
|
|
|
firewall and only use the <emphasis role="bold">balance</emphasis> option
|
|
|
|
|
in <filename>/etc/shorewall/providers</filename> on the Comcast provider
|
|
|
|
|
whose default route in the main table is established by DHCP. By
|
|
|
|
|
specifying the <emphasis role="bold">fallback</emphasis> option on
|
|
|
|
|
Avvanta, I ensure that there is still a default route if Comcast is down.
|
2009-02-25 20:17:36 +01:00
|
|
|
|
<link linkend="lsm">lsm</link> is used to monitor the links.</para>
|
2009-01-06 00:40:56 +01:00
|
|
|
|
|
|
|
|
|
<para><filename>/etc/sysctl.conf</filename>:</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>net.ipv4.conf.all.rp_filter = 0</programlisting>
|
|
|
|
|
|
2009-01-07 17:25:14 +01:00
|
|
|
|
<para><filename>/etc/shorewall/shorewall.conf</filename>:</para>
|
|
|
|
|
|
2009-01-30 23:20:22 +01:00
|
|
|
|
<programlisting>ROUTE_FILTER=No
|
|
|
|
|
RESTORE_DEFAULT_ROUTE=No</programlisting>
|
|
|
|
|
|
2009-02-28 04:45:43 +01:00
|
|
|
|
<para>RESTORE_DEFAULT_ROUTE=No causes the default route in the main table
|
|
|
|
|
to be deleted when the Comcast link is unavailable. That way, the default
|
|
|
|
|
route in the default table will be used until Comcast is available
|
|
|
|
|
again.</para>
|
2009-01-07 17:25:14 +01:00
|
|
|
|
|
2009-01-06 00:40:56 +01:00
|
|
|
|
<para><filename>/etc/shorewall/providers</filename>:</para>
|
|
|
|
|
|
2009-01-06 19:33:19 +01:00
|
|
|
|
<programlisting>#NAME NUMBER MARK DUPLICATE INTERFACE GATEWAY OPTIONS COPY
|
2009-01-07 17:25:14 +01:00
|
|
|
|
Avvanta 1 0x100 main eth0 206.124.146.254 track,loose,fallback eth2,eth4,tun*
|
2009-01-30 23:20:22 +01:00
|
|
|
|
Comcast 2 0x200 main eth3 detect track,balance eth2,eth4,tun*
|
2009-01-06 00:40:56 +01:00
|
|
|
|
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE</programlisting>
|
|
|
|
|
|
|
|
|
|
<para>The <emphasis role="bold">loose</emphasis> option on Avvanta results
|
|
|
|
|
in fewer routing rules. The first two routing rules below insure that all
|
|
|
|
|
traffic from Avvanta-assigned IP addresses is sent via the Avvanta
|
2009-01-31 18:27:24 +01:00
|
|
|
|
provider. The 'tun*' included in the COPY column is there because I run a
|
|
|
|
|
routed OpenVPN server on the firewall.</para>
|
2009-01-06 00:40:56 +01:00
|
|
|
|
|
|
|
|
|
<para><filename>/etc/shorewall/route_rules</filename>:</para>
|
|
|
|
|
|
2009-01-07 17:25:14 +01:00
|
|
|
|
<programlisting>#SOURCE DEST PROVIDER PRIORITY
|
2009-01-30 23:20:22 +01:00
|
|
|
|
- 172.20.0.0/24 main 1000 # Addresses assigned by routed OpenVPN server
|
2009-01-07 17:25:14 +01:00
|
|
|
|
206.124.146.176/30 - Avvanta 26000
|
|
|
|
|
206.124.146.180 - Avvanta 26000
|
|
|
|
|
- 216.168.3.44 Avvanta 26000 # Avvanta NNTP Server -- verifies source IP address
|
2009-01-06 00:40:56 +01:00
|
|
|
|
#LAST LINE -- ADD YOUR ENTRIES BEFORE THIS ONE -- DO NOT REMOVE</programlisting>
|
|
|
|
|
|
|
|
|
|
<para>The <filename>/etc/shorewall/route_rules </filename>entries provide
|
|
|
|
|
all of the provider selection necessary so my
|
|
|
|
|
<filename>/etc/shorewall/tcrules</filename> file is used exclusively for
|
2009-01-06 00:45:12 +01:00
|
|
|
|
traffic shaping of the Avvanta line. Note that I still need to provide
|
|
|
|
|
values in the MARK colum of <filename>/etc/shorewall/providers</filename>
|
|
|
|
|
because I specify <emphasis role="bold">track</emphasis> on both
|
|
|
|
|
providers.</para>
|
2009-01-06 00:40:56 +01:00
|
|
|
|
|
|
|
|
|
<para>Here is the output of <command>shorewall show
|
|
|
|
|
routing</command>:</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>Routing Rules
|
|
|
|
|
|
2009-01-07 17:25:14 +01:00
|
|
|
|
0: from all lookup local
|
|
|
|
|
1000: from all to 172.20.0.0/24 lookup main
|
2009-01-06 00:40:56 +01:00
|
|
|
|
10000: from all fwmark 0x100 lookup Avvanta
|
|
|
|
|
10001: from all fwmark 0x200 lookup Comcast
|
|
|
|
|
20256: from 71.227.156.229 lookup Comcast
|
|
|
|
|
26000: from 206.124.146.176/30 lookup Avvanta
|
|
|
|
|
26000: from 206.124.146.180 lookup Avvanta
|
|
|
|
|
26000: from all to 216.168.3.44 lookup Avvanta
|
|
|
|
|
32766: from all lookup main
|
|
|
|
|
32767: from all lookup default
|
|
|
|
|
|
|
|
|
|
Table Avvanta:
|
|
|
|
|
|
|
|
|
|
206.124.146.254 dev eth0 scope link src 206.124.146.176
|
|
|
|
|
206.124.146.177 dev eth4 scope link
|
|
|
|
|
172.20.1.0/24 dev eth2 proto kernel scope link src 172.20.1.254
|
|
|
|
|
206.124.146.0/24 dev eth0 proto kernel scope link src 206.124.146.176
|
|
|
|
|
169.254.0.0/16 dev eth0 scope link
|
|
|
|
|
default via 206.124.146.254 dev eth0 src 206.124.146.176
|
|
|
|
|
|
|
|
|
|
Table Comcast:
|
|
|
|
|
|
|
|
|
|
206.124.146.177 dev eth4 scope link
|
|
|
|
|
71.227.156.1 dev eth3 scope link src 71.227.156.229
|
|
|
|
|
172.20.1.0/24 dev eth2 proto kernel scope link src 172.20.1.254
|
|
|
|
|
71.227.156.0/23 dev eth3 proto kernel scope link src 71.227.156.229
|
|
|
|
|
default via 71.227.156.1 dev eth3 src 71.227.156.229
|
|
|
|
|
|
|
|
|
|
Table default:
|
|
|
|
|
|
2009-01-06 19:33:19 +01:00
|
|
|
|
default via 206.124.146.254 dev eth0 metric 1
|
|
|
|
|
|
2009-01-06 00:40:56 +01:00
|
|
|
|
Table local:
|
|
|
|
|
|
|
|
|
|
broadcast 127.255.255.255 dev lo proto kernel scope link src 127.0.0.1
|
|
|
|
|
broadcast 172.20.1.0 dev eth2 proto kernel scope link src 172.20.1.254
|
|
|
|
|
broadcast 206.124.146.255 dev eth0 proto kernel scope link src 206.124.146.176
|
|
|
|
|
local 206.124.146.179 dev eth0 proto kernel scope host src 206.124.146.176
|
|
|
|
|
local 206.124.146.178 dev eth0 proto kernel scope host src 206.124.146.176
|
|
|
|
|
local 206.124.146.176 dev eth0 proto kernel scope host src 206.124.146.176
|
|
|
|
|
local 206.124.146.176 dev eth4 proto kernel scope host src 206.124.146.176
|
|
|
|
|
broadcast 71.227.157.255 dev eth3 proto kernel scope link src 71.227.156.229
|
|
|
|
|
broadcast 71.227.156.0 dev eth3 proto kernel scope link src 71.227.156.229
|
|
|
|
|
local 172.20.1.254 dev eth2 proto kernel scope host src 172.20.1.254
|
|
|
|
|
local 127.0.0.2 dev lo proto kernel scope host src 127.0.0.1
|
|
|
|
|
broadcast 172.20.1.255 dev eth2 proto kernel scope link src 172.20.1.254
|
|
|
|
|
local 71.227.156.229 dev eth3 proto kernel scope host src 71.227.156.229
|
|
|
|
|
broadcast 206.124.146.0 dev eth0 proto kernel scope link src 206.124.146.176
|
|
|
|
|
broadcast 127.0.0.0 dev lo proto kernel scope link src 127.0.0.1
|
|
|
|
|
local 206.124.146.180 dev eth0 proto kernel scope host src 206.124.146.176
|
|
|
|
|
local 127.0.0.1 dev lo proto kernel scope host src 127.0.0.1
|
|
|
|
|
local 127.0.0.0/8 dev lo proto kernel scope host src 127.0.0.1
|
|
|
|
|
|
|
|
|
|
Table main:
|
|
|
|
|
|
|
|
|
|
206.124.146.177 dev eth4 scope link
|
|
|
|
|
172.20.1.0/24 dev eth2 proto kernel scope link src 172.20.1.254
|
|
|
|
|
206.124.146.0/24 dev eth0 proto kernel scope link src 206.124.146.176
|
|
|
|
|
71.227.156.0/23 dev eth3 proto kernel scope link src 71.227.156.229
|
|
|
|
|
169.254.0.0/16 dev eth0 scope link
|
|
|
|
|
127.0.0.0/8 dev lo scope link
|
|
|
|
|
default via 71.227.156.1 dev eth3 </programlisting>
|
|
|
|
|
|
|
|
|
|
<para><filename>/etc/shorewall/interfaces</filename>:</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>#ZONE INTERFACE BROADCAST OPTIONS
|
|
|
|
|
loc eth2 detect dhcp,routeback
|
|
|
|
|
dmz eth4 detect
|
|
|
|
|
net eth0 detect dhcp,blacklist,tcpflags,optional
|
|
|
|
|
net eth3 detect dhcp,blacklist,tcpflags,optional
|
|
|
|
|
#LAST LINE -- ADD YOUR ENTRIES BEFORE THIS ONE -- DO NOT REMOVE</programlisting>
|
|
|
|
|
|
|
|
|
|
<para><filename>/etc/shorewall/masq</filename>:</para>
|
|
|
|
|
|
|
|
|
|
<programlisting>#INTERFACE SOURCE ADDRESS PROTO PORT(S) IPSEC
|
|
|
|
|
|
|
|
|
|
COMMENT Masquerade Local Network
|
|
|
|
|
eth3 0.0.0.0/0
|
|
|
|
|
eth0 !206.124.146.0/24 206.124.146.179
|
|
|
|
|
|
2009-01-30 23:20:22 +01:00
|
|
|
|
#LAST LINE -- ADD YOUR ENTRIES ABOVE THIS LINE -- DO NOT REMOVE</programlisting>
|
2009-01-06 00:40:56 +01:00
|
|
|
|
|
|
|
|
|
<para>All traffic leaving eth3 must use the dynamic IP address assigned to
|
|
|
|
|
that interface as the SOURCE address. All traffic leaving eth0 that does
|
2009-01-07 17:25:14 +01:00
|
|
|
|
not have a SOURCE address falling within the Avvanta subnet
|
|
|
|
|
(206.124.146.0/24) must have its SOURCE address changed to
|
|
|
|
|
206.124.146.179.</para>
|
2009-01-06 00:40:56 +01:00
|
|
|
|
</section>
|
2008-11-16 16:02:51 +01:00
|
|
|
|
</article>
|