2002-12-28 16:38:03 +01:00
|
|
|
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
|
2002-09-16 19:13:39 +02:00
|
|
|
|
<html>
|
|
|
|
|
|
<head>
|
2003-07-16 20:59:33 +02:00
|
|
|
|
|
2002-12-28 16:38:03 +01:00
|
|
|
|
<meta http-equiv="Content-Language" content="en-us">
|
2003-07-16 20:59:33 +02:00
|
|
|
|
|
2002-12-28 16:38:03 +01:00
|
|
|
|
<meta name="GENERATOR" content="Microsoft FrontPage 5.0">
|
2003-07-16 20:59:33 +02:00
|
|
|
|
|
2002-12-28 16:38:03 +01:00
|
|
|
|
<meta name="ProgId" content="FrontPage.Editor.Document">
|
2003-07-16 20:59:33 +02:00
|
|
|
|
|
2002-12-28 16:38:03 +01:00
|
|
|
|
<meta http-equiv="Content-Type"
|
|
|
|
|
|
content="text/html; charset=windows-1252">
|
|
|
|
|
|
<title>VPN</title>
|
2002-09-16 19:13:39 +02:00
|
|
|
|
</head>
|
2002-12-28 16:38:03 +01:00
|
|
|
|
<body>
|
2003-07-16 20:59:33 +02:00
|
|
|
|
|
2002-12-28 16:38:03 +01:00
|
|
|
|
<table border="0" cellpadding="0" cellspacing="0"
|
|
|
|
|
|
style="border-collapse: collapse;" bordercolor="#111111" width="100%"
|
2003-07-16 20:59:33 +02:00
|
|
|
|
id="AutoNumber1" bgcolor="#3366ff" height="90">
|
|
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td width="100%">
|
2002-12-28 16:38:03 +01:00
|
|
|
|
<h1 align="center"><font color="#ffffff">VPN</font></h1>
|
2003-07-16 20:59:33 +02:00
|
|
|
|
</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
|
|
|
|
|
|
</tbody>
|
2002-12-28 16:38:03 +01:00
|
|
|
|
</table>
|
2003-07-16 20:59:33 +02:00
|
|
|
|
|
|
|
|
|
|
<p>It is often the case that a system behind the firewall needs to be able
|
|
|
|
|
|
to access a remote network through Virtual Private Networking (VPN). The
|
|
|
|
|
|
two most common means for doing this are IPSEC and PPTP. The basic setup
|
2002-12-28 16:38:03 +01:00
|
|
|
|
is shown in the following diagram:</p>
|
2003-07-16 20:59:33 +02:00
|
|
|
|
|
2002-12-28 16:38:03 +01:00
|
|
|
|
<p align="center"><img border="0" src="images/VPN.png" width="568"
|
|
|
|
|
|
height="796">
|
2003-07-16 20:59:33 +02:00
|
|
|
|
</p>
|
|
|
|
|
|
|
|
|
|
|
|
<p align="left">A system with an RFC 1918 address needs to access a remote
|
|
|
|
|
|
network through a remote gateway. For this example, we will assume that the
|
|
|
|
|
|
local system has IP address 192.168.1.12 and that the remote gateway has
|
|
|
|
|
|
IP address 192.0.2.224.</p>
|
|
|
|
|
|
|
|
|
|
|
|
<p align="left">If PPTP is being used, there are no firewall requirements
|
|
|
|
|
|
beyond the default loc->net ACCEPT policy. There is one restriction however:
|
|
|
|
|
|
Only one local system at a time can be connected to a single remote gateway
|
|
|
|
|
|
unless you patch your kernel from the 'Patch-o-matic' patches available at
|
|
|
|
|
|
<a href="http://www.netfilter.org">http://www.netfilter.org</a>. </p>
|
|
|
|
|
|
|
|
|
|
|
|
<p align="left">If IPSEC is being used then only one system may connect to
|
|
|
|
|
|
the remote gateway and there are firewall configuration requirements as follows:</p>
|
|
|
|
|
|
|
|
|
|
|
|
<blockquote>
|
2002-12-28 16:38:03 +01:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;"
|
|
|
|
|
|
bordercolor="#111111" id="AutoNumber2" height="98">
|
2003-07-16 20:59:33 +02:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td height="38"><u><b>ACTION</b></u></td>
|
|
|
|
|
|
<td height="38"><u><b>SOURCE</b></u></td>
|
|
|
|
|
|
<td height="38"><u><b>DESTINATION</b></u></td>
|
|
|
|
|
|
<td height="38"><u><b>PROTOCOL</b></u></td>
|
|
|
|
|
|
<td height="38"><u><b>PORT</b></u></td>
|
|
|
|
|
|
<td height="38"><u><b>CLIENT<br>
|
|
|
|
|
|
PORT</b></u></td>
|
|
|
|
|
|
<td height="38"><u><b>ORIGINAL<br>
|
|
|
|
|
|
DEST</b></u></td>
|
|
|
|
|
|
</tr>
|
2002-12-28 16:38:03 +01:00
|
|
|
|
<tr>
|
2003-07-16 20:59:33 +02:00
|
|
|
|
<td height="19">DNAT</td>
|
|
|
|
|
|
<td height="19">net:192.0.2.224</td>
|
|
|
|
|
|
<td height="19">loc:192.168.1.12</td>
|
|
|
|
|
|
<td height="19">50</td>
|
|
|
|
|
|
<td height="19"><EFBFBD></td>
|
|
|
|
|
|
<td height="19"><EFBFBD></td>
|
|
|
|
|
|
<td height="19"><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td height="19">DNAT</td>
|
|
|
|
|
|
<td height="19">net:192.0.2.224</td>
|
|
|
|
|
|
<td height="19">loc:192.168.1.12</td>
|
|
|
|
|
|
<td height="19">udp</td>
|
|
|
|
|
|
<td height="19">500</td>
|
|
|
|
|
|
<td height="19"><EFBFBD></td>
|
|
|
|
|
|
<td height="19"><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
|
|
|
|
|
|
</tbody>
|
2002-09-16 19:13:39 +02:00
|
|
|
|
</table>
|
2003-07-16 20:59:33 +02:00
|
|
|
|
</blockquote>
|
|
|
|
|
|
|
|
|
|
|
|
<p>If you want to be able to give access to all of your local systems to the
|
|
|
|
|
|
remote network, you should consider running a VPN client on your firewall.
|
2002-12-28 16:38:03 +01:00
|
|
|
|
As starting points, see <a
|
2003-07-16 20:59:33 +02:00
|
|
|
|
href="http://www.shorewall.net/Documentation.htm#Tunnels"> http://www.shorewall.net/Documentation.htm#Tunnels</a>
|
2002-12-28 16:38:03 +01:00
|
|
|
|
or <a href="http://www.shorewall.net/PPTP.htm">http://www.shorewall.net/PPTP.htm</a>.</p>
|
2003-07-16 20:59:33 +02:00
|
|
|
|
|
2002-12-28 16:38:03 +01:00
|
|
|
|
<p><font size="2">Last modified 12/21/2002 - <a href="support.htm">Tom Eastep</a></font></p>
|
2003-07-16 20:59:33 +02:00
|
|
|
|
|
|
|
|
|
|
<p><font face="Trebuchet MS"><a href="copyright.htm"> <font size="2">Copyright</font>
|
2002-12-28 16:38:03 +01:00
|
|
|
|
<EFBFBD> <font size="2">2002 Thomas M. Eastep.</font></a></font></p>
|
2003-07-16 20:59:33 +02:00
|
|
|
|
|
2002-12-28 16:38:03 +01:00
|
|
|
|
<p><EFBFBD></p>
|
2003-07-16 20:59:33 +02:00
|
|
|
|
<br>
|
|
|
|
|
|
<br>
|
2002-09-16 19:13:39 +02:00
|
|
|
|
</body>
|
|
|
|
|
|
</html>
|
