mirror of
https://gitlab.com/shorewall/code.git
synced 2024-11-24 08:33:40 +01:00
338 lines
8.2 KiB
XML
338 lines
8.2 KiB
XML
|
<?xml version="1.0" encoding="UTF-8"?>
|
||
|
|
<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
|
||
|
|
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
|
||
|
|
<article id="OPENVPN">
|
||
|
|
<articleinfo>
|
||
|
|
<title>OpenVPN Tunnels</title>
|
||
|
|
|
||
|
|
<authorgroup>
|
||
|
|
<author>
|
||
|
|
<firstname>Tom</firstname>
|
||
|
|
|
||
|
|
<surname>Eastep</surname>
|
||
|
|
</author>
|
||
|
|
|
||
|
|
<author>
|
||
|
|
<firstname>Simon</firstname>
|
||
|
|
|
||
|
|
<surname>Mater</surname>
|
||
|
|
</author>
|
||
|
|
</authorgroup>
|
||
|
|
|
||
|
|
<pubdate>2003-02-04</pubdate>
|
||
|
|
|
||
|
|
<copyright>
|
||
|
|
<year>2003</year>
|
||
|
|
|
||
|
|
<holder>Thomas M. Eastep</holder>
|
||
|
|
|
||
|
|
<holder>Simon Mater</holder>
|
||
|
|
</copyright>
|
||
|
|
|
||
|
|
<legalnotice>
|
||
|
|
<para>Permission is granted to copy, distribute and/or modify this
|
||
|
|
document under the terms of the GNU Free Documentation License, Version
|
||
|
|
1.2 or any later version published by the Free Software Foundation; with
|
||
|
|
no Invariant Sections, with no Front-Cover, and with no Back-Cover
|
||
|
|
Texts. A copy of the license is included in the section entitled "<ulink
|
||
|
|
url="GnuCopyright.htm">GNU Free Documentation License</ulink>".</para>
|
||
|
|
</legalnotice>
|
||
|
|
</articleinfo>
|
||
|
|
|
||
|
|
<para>OpenVPN is a robust and highly configurable VPN (Virtual Private
|
||
|
|
Network) daemon which can be used to securely link two or more private
|
||
|
|
networks using an encrypted tunnel over the internet. OpenVPN is an Open
|
||
|
|
Source project and is <ulink
|
||
|
|
url="http://openvpn.sourceforge.net/license.html">licensed under the GPL</ulink>.
|
||
|
|
OpenVPN can be downloaded from <ulink url="http://openvpn.sourceforge.net/">http://openvpn.sourceforge.net/</ulink>.</para>
|
||
|
|
|
||
|
|
<para>OpenVPN support was added to Shorewall in version 1.3.14.</para>
|
||
|
|
|
||
|
|
<section>
|
||
|
|
<title>Bridging two Masqueraded Networks</title>
|
||
|
|
|
||
|
|
<para>Suppose that we have the following situation:</para>
|
||
|
|
|
||
|
|
<graphic fileref="images/TwoNets1.png" />
|
||
|
|
|
||
|
|
<para>We want systems in the 192.168.1.0/24 subnetwork to be able to
|
||
|
|
communicate with the systems in the 10.0.0.0/8 network. This is
|
||
|
|
accomplished through use of the /etc/shorewall/tunnels file and the
|
||
|
|
/etc/shorewall/policy file and OpenVPN.</para>
|
||
|
|
|
||
|
|
<para>While it was possible to use the Shorewall start and stop script to
|
||
|
|
start and stop OpenVPN, I decided to use the init script of OpenVPN to
|
||
|
|
start and stop it.</para>
|
||
|
|
|
||
|
|
<para>On each firewall, you will need to declare a zone to represent the
|
||
|
|
remote subnet. We'll assume that this zone is called 'vpn' and
|
||
|
|
declare it in /etc/shorewall/zones on both systems as follows.</para>
|
||
|
|
|
||
|
|
<table>
|
||
|
|
<title>/etc/shorewall/zones system A & B</title>
|
||
|
|
|
||
|
|
<tgroup cols="3">
|
||
|
|
<thead>
|
||
|
|
<row>
|
||
|
|
<entry align="center">ZONE</entry>
|
||
|
|
|
||
|
|
<entry align="center">DISPLAY</entry>
|
||
|
|
|
||
|
|
<entry align="center">COMMENTS</entry>
|
||
|
|
</row>
|
||
|
|
</thead>
|
||
|
|
|
||
|
|
<tbody>
|
||
|
|
<row>
|
||
|
|
<entry>vpn</entry>
|
||
|
|
|
||
|
|
<entry>VPN</entry>
|
||
|
|
|
||
|
|
<entry>Remote Subnet</entry>
|
||
|
|
</row>
|
||
|
|
</tbody>
|
||
|
|
</tgroup>
|
||
|
|
</table>
|
||
|
|
|
||
|
|
<para>On system A, the 10.0.0.0/8 will comprise the <emphasis role="bold">vpn</emphasis>
|
||
|
|
zone. In /etc/shorewall/interfaces:</para>
|
||
|
|
|
||
|
|
<table>
|
||
|
|
<title>etc/shorewall/interfaces system A</title>
|
||
|
|
|
||
|
|
<tgroup cols="4">
|
||
|
|
<thead>
|
||
|
|
<row>
|
||
|
|
<entry align="center">ZONE</entry>
|
||
|
|
|
||
|
|
<entry align="center">INTERFACE</entry>
|
||
|
|
|
||
|
|
<entry align="center">BROADCAST</entry>
|
||
|
|
|
||
|
|
<entry align="center">OPTIONS</entry>
|
||
|
|
</row>
|
||
|
|
</thead>
|
||
|
|
|
||
|
|
<tbody>
|
||
|
|
<row>
|
||
|
|
<entry>vpn</entry>
|
||
|
|
|
||
|
|
<entry>tun0</entry>
|
||
|
|
|
||
|
|
<entry></entry>
|
||
|
|
|
||
|
|
<entry></entry>
|
||
|
|
</row>
|
||
|
|
</tbody>
|
||
|
|
</tgroup>
|
||
|
|
</table>
|
||
|
|
|
||
|
|
<para>In /etc/shorewall/tunnels on system A, we need the following:</para>
|
||
|
|
|
||
|
|
<table>
|
||
|
|
<title>/etc/shorewall/tunnels system A</title>
|
||
|
|
|
||
|
|
<tgroup cols="4">
|
||
|
|
<thead>
|
||
|
|
<row>
|
||
|
|
<entry align="center">TYPE</entry>
|
||
|
|
|
||
|
|
<entry align="center">ZONE</entry>
|
||
|
|
|
||
|
|
<entry align="center">GATEWAY</entry>
|
||
|
|
|
||
|
|
<entry align="center">GATEWAY ZONE</entry>
|
||
|
|
</row>
|
||
|
|
</thead>
|
||
|
|
|
||
|
|
<tbody>
|
||
|
|
<row>
|
||
|
|
<entry>openvpn</entry>
|
||
|
|
|
||
|
|
<entry>net</entry>
|
||
|
|
|
||
|
|
<entry>134.28.54.2</entry>
|
||
|
|
|
||
|
|
<entry></entry>
|
||
|
|
</row>
|
||
|
|
</tbody>
|
||
|
|
</tgroup>
|
||
|
|
</table>
|
||
|
|
|
||
|
|
<para>This entry in /etc/shorewall/tunnels opens the firewall so that
|
||
|
|
OpenVPN traffic on the default port 5000/udp will be accepted to/from the
|
||
|
|
remote gateway. If you change the port used by OpenVPN to 7777, you can
|
||
|
|
define /etc/shorewall/tunnels like this:</para>
|
||
|
|
|
||
|
|
<table>
|
||
|
|
<title>/etc/shorewall/tunnels port 7777</title>
|
||
|
|
|
||
|
|
<tgroup cols="4">
|
||
|
|
<thead>
|
||
|
|
<row>
|
||
|
|
<entry align="center">TYPE</entry>
|
||
|
|
|
||
|
|
<entry align="center">ZONE</entry>
|
||
|
|
|
||
|
|
<entry align="center">GATEWAY</entry>
|
||
|
|
|
||
|
|
<entry align="center">GATEWAY ZONE</entry>
|
||
|
|
</row>
|
||
|
|
</thead>
|
||
|
|
|
||
|
|
<tbody>
|
||
|
|
<row>
|
||
|
|
<entry>openvpn:7777</entry>
|
||
|
|
|
||
|
|
<entry>net</entry>
|
||
|
|
|
||
|
|
<entry>134.28.54.2</entry>
|
||
|
|
|
||
|
|
<entry></entry>
|
||
|
|
</row>
|
||
|
|
</tbody>
|
||
|
|
</tgroup>
|
||
|
|
</table>
|
||
|
|
|
||
|
|
<para>This is the OpenVPN config on system A:</para>
|
||
|
|
|
||
|
|
<programlisting>dev tun
|
||
|
|
local 206.162.148.9
|
||
|
|
remote 134.28.54.2
|
||
|
|
ifconfig 192.168.99.1 192.168.99.2
|
||
|
|
up ./route-a.up
|
||
|
|
tls-server
|
||
|
|
dh dh1024.pem
|
||
|
|
ca ca.crt
|
||
|
|
cert my-a.crt
|
||
|
|
key my-a.key
|
||
|
|
comp-lzo
|
||
|
|
verb 5</programlisting>
|
||
|
|
|
||
|
|
<para>Similarly, On system B the 192.168.1.0/24 subnet will comprise the
|
||
|
|
<emphasis role="bold">vpn</emphasis> zone. In /etc/shorewall/interfaces:</para>
|
||
|
|
|
||
|
|
<table>
|
||
|
|
<title>/etc/shorewall/interfaces system B</title>
|
||
|
|
|
||
|
|
<tgroup cols="4">
|
||
|
|
<thead>
|
||
|
|
<row>
|
||
|
|
<entry align="center">ZONE</entry>
|
||
|
|
|
||
|
|
<entry align="center">INTERFACE</entry>
|
||
|
|
|
||
|
|
<entry align="center">BROADCAST</entry>
|
||
|
|
|
||
|
|
<entry align="center">OPTIONS</entry>
|
||
|
|
</row>
|
||
|
|
</thead>
|
||
|
|
|
||
|
|
<tbody>
|
||
|
|
<row>
|
||
|
|
<entry>vpn</entry>
|
||
|
|
|
||
|
|
<entry>tun0</entry>
|
||
|
|
|
||
|
|
<entry>192.168.1.255</entry>
|
||
|
|
|
||
|
|
<entry></entry>
|
||
|
|
</row>
|
||
|
|
</tbody>
|
||
|
|
</tgroup>
|
||
|
|
</table>
|
||
|
|
|
||
|
|
<para>In /etc/shorewall/tunnels on system B, we have:</para>
|
||
|
|
|
||
|
|
<table>
|
||
|
|
<title>/etc/shorewall/tunnels system B</title>
|
||
|
|
|
||
|
|
<tgroup cols="4">
|
||
|
|
<thead>
|
||
|
|
<row>
|
||
|
|
<entry align="center">TYPE</entry>
|
||
|
|
|
||
|
|
<entry align="center">ZONE</entry>
|
||
|
|
|
||
|
|
<entry align="center">GATEWAY</entry>
|
||
|
|
|
||
|
|
<entry align="center">GATEWAY ZONE</entry>
|
||
|
|
</row>
|
||
|
|
</thead>
|
||
|
|
|
||
|
|
<tbody>
|
||
|
|
<row>
|
||
|
|
<entry>openvpn</entry>
|
||
|
|
|
||
|
|
<entry>net</entry>
|
||
|
|
|
||
|
|
<entry>206.191.148.9</entry>
|
||
|
|
|
||
|
|
<entry></entry>
|
||
|
|
</row>
|
||
|
|
</tbody>
|
||
|
|
</tgroup>
|
||
|
|
</table>
|
||
|
|
|
||
|
|
<para>And in the OpenVPN config on system B:</para>
|
||
|
|
|
||
|
|
<programlisting>dev tun
|
||
|
|
local 134.28.54.2
|
||
|
|
remote 206.162.148.9
|
||
|
|
ifconfig 192.168.99.2 192.168.99.1
|
||
|
|
up ./route-b.up
|
||
|
|
tls-client
|
||
|
|
ca ca.crt
|
||
|
|
cert my-b.crt
|
||
|
|
key my-b.key
|
||
|
|
comp-lzo
|
||
|
|
verb 5</programlisting>
|
||
|
|
|
||
|
|
<para>You will need to allow traffic between the "vpn" zone and
|
||
|
|
the "loc" zone on both systems -- if you simply want to admit all
|
||
|
|
traffic in both directions, you can use the policy file:</para>
|
||
|
|
|
||
|
|
<table>
|
||
|
|
<title>/etc/shorewall/policy system A & B</title>
|
||
|
|
|
||
|
|
<tgroup cols="4">
|
||
|
|
<thead>
|
||
|
|
<row>
|
||
|
|
<entry align="center">SOURCE</entry>
|
||
|
|
|
||
|
|
<entry align="center">DEST</entry>
|
||
|
|
|
||
|
|
<entry align="center">POLICY</entry>
|
||
|
|
|
||
|
|
<entry align="center">LOG LEVEL</entry>
|
||
|
|
</row>
|
||
|
|
</thead>
|
||
|
|
|
||
|
|
<tbody>
|
||
|
|
<row>
|
||
|
|
<entry>loc</entry>
|
||
|
|
|
||
|
|
<entry>vpn</entry>
|
||
|
|
|
||
|
|
<entry>ACCEPT</entry>
|
||
|
|
|
||
|
|
<entry></entry>
|
||
|
|
</row>
|
||
|
|
|
||
|
|
<row>
|
||
|
|
<entry>vpn</entry>
|
||
|
|
|
||
|
|
<entry>loc</entry>
|
||
|
|
|
||
|
|
<entry>ACCEPT</entry>
|
||
|
|
|
||
|
|
<entry></entry>
|
||
|
|
</row>
|
||
|
|
</tbody>
|
||
|
|
</tgroup>
|
||
|
|
</table>
|
||
|
|
|
||
|
|
<para>On both systems, restart Shorewall and start OpenVPN. The systems in
|
||
|
|
the two masqueraded subnetworks can now talk to each other.</para>
|
||
|
|
</section>
|
||
|
|
</article>
|