2002-08-13 22:45:21 +02:00
|
|
|
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
|
|
|
|
|
|
<html>
|
|
|
|
|
|
<head>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<meta http-equiv="Content-Type"
|
|
|
|
|
|
content="text/html; charset=windows-1252">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-08-13 22:45:21 +02:00
|
|
|
|
<meta name="GENERATOR" content="Microsoft FrontPage 5.0">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<meta name="ProgId" content="FrontPage.Editor.Document">
|
|
|
|
|
|
<title>Shorewall 1.3 Documentation</title>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<base
|
|
|
|
|
|
target="_self">
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<meta name="Microsoft Theme" content="none, default">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<meta name="Microsoft Border" content="none, default">
|
|
|
|
|
|
</head>
|
|
|
|
|
|
<body>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="0" cellpadding="0" cellspacing="0"
|
|
|
|
|
|
style="border-collapse: collapse;" width="100%" id="AutoNumber4"
|
|
|
|
|
|
bgcolor="#400169" height="90">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td width="100%">
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h1 align="center"><font color="#ffffff">Shorewall 1.3 Reference</font></h1>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
|
|
|
|
|
|
</tbody>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h2 align="center">This documentation is intended primarily for reference.
|
2002-11-24 21:08:19 +01:00
|
|
|
|
Step-by-step instructions for configuring Shorewall in common setups
|
|
|
|
|
|
may be found in the <a href="shorewall_quickstart_guide.htm">QuickStart
|
|
|
|
|
|
Guides</a>.</h2>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h2>Components</h2>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Shorewall consists of the following components: </p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b><a href="#Variables">params</a></b> -- a parameter file
|
|
|
|
|
|
installed in /etc/shorewall that can be used to establish the values
|
|
|
|
|
|
of shell variables for use in other files.</li>
|
|
|
|
|
|
<li><b> <a href="#Conf">shorewall.conf</a></b> -- a parameter
|
|
|
|
|
|
file installed in /etc/shorewall that is used to set several
|
|
|
|
|
|
firewall parameters.</li>
|
|
|
|
|
|
<li><b> <a href="#Zones">zones</a></b> - a parameter file installed
|
|
|
|
|
|
in /etc/shorewall that defines a network partitioning into "zones"</li>
|
|
|
|
|
|
<li><b> <a href="#Policy">policy</a></b> -- a parameter file
|
|
|
|
|
|
installed in /etc/shorewall/ that establishes overall firewall
|
|
|
|
|
|
policy.</li>
|
|
|
|
|
|
<li><b> <a href="#Rules">rules</a> </b> -- a parameter file
|
|
|
|
|
|
installed in /etc/shorewall and used to express firewall rules
|
|
|
|
|
|
that are exceptions to the high-level policies established in
|
|
|
|
|
|
/etc/shorewall/policy.</li>
|
|
|
|
|
|
<li><b><a href="#Blacklist">blacklist</a> -- </b>a parameter file
|
|
|
|
|
|
installed in /etc/shorewall and used to list blacklisted IP/subnet/MAC
|
|
|
|
|
|
addresses.</li>
|
|
|
|
|
|
<li><b> functions</b> -- a set of shell functions used by both
|
|
|
|
|
|
the firewall and shorewall shell programs. Installed in /etc/shorewall
|
|
|
|
|
|
prior to version 1.3.2, in /var/lib/shorewall in version s 1.3.2-1.3.8
|
|
|
|
|
|
and in /usr/lib/shorewall in later versions.</li>
|
|
|
|
|
|
<li><b> <a href="#modules">modules</a></b> -- a parameter file
|
|
|
|
|
|
installed in /etc/shorewall and that specifies kernel modules
|
|
|
|
|
|
and their parameters. Shorewall will automatically load the modules
|
|
|
|
|
|
specified in this file.</li>
|
|
|
|
|
|
<li><a href="#TOS"><b> tos</b> </a>-- a parameter file installed
|
|
|
|
|
|
in /etc/shorewall that is used to specify how the Type of Service
|
|
|
|
|
|
(TOS) field in packets is to be set.</li>
|
|
|
|
|
|
<li><a href="#Scripts"><b> icmp.def</b> </a>-- a parameter file
|
|
|
|
|
|
installed in /etc/shorewall and that specifies the default handling
|
|
|
|
|
|
of ICMP packets when the applicable policy is DROP or REJECT.</li>
|
|
|
|
|
|
<li><b><a href="#Scripts">common.def</a></b> -- a parameter file
|
|
|
|
|
|
installed in in /etc/shorewall that defines firewall-wide rules that
|
|
|
|
|
|
are applied before a DROP or REJECT policy is applied.</li>
|
|
|
|
|
|
<li><b> <a href="#Interfaces">interfaces</a> </b> -- a parameter
|
|
|
|
|
|
file installed in /etc/shorewall/ and used to describe the
|
|
|
|
|
|
interfaces on the firewall system.</li>
|
|
|
|
|
|
<li><a href="#Hosts"><b> hosts</b> </a>-- a parameter file installed
|
|
|
|
|
|
in /etc/shorewall/ and used to describe individual hosts or
|
|
|
|
|
|
subnetworks in zones.</li>
|
|
|
|
|
|
<li><b><a href="#Maclist">maclist</a> </b>-- a parameter file installed
|
|
|
|
|
|
in /etc/shorewall and used to verify the MAC address (and possibly also
|
|
|
|
|
|
the IP address(es)) of devices.<br>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li><b> <a href="#Masq">masq</a></b> - This file
|
|
|
|
|
|
also describes IP masquerading under Shorewall and is installed in
|
|
|
|
|
|
/etc/shorewall.</li>
|
|
|
|
|
|
<li><b><a href="shorewall_firewall_structure.htm">firewall</a></b>
|
|
|
|
|
|
-- a shell program that reads the configuration files in /etc/shorewall
|
|
|
|
|
|
and configures your firewall. This file is installed in your
|
|
|
|
|
|
init.d directory (/etc/rc.d/init.d ) where it is renamed <i>shorewall.</i><EFBFBD>
|
|
|
|
|
|
/etc/shorewall/firewall (/var/lib/shorewall/firewall in versions 1.3.2-1.3.8
|
|
|
|
|
|
and /usr/lib/shorewall/firewall in 1.3.9 and later) is a symbolic link
|
|
|
|
|
|
to this program.</li>
|
|
|
|
|
|
<li><b> <a href="#NAT">nat</a></b> -- a parameter file in /etc/shorewall
|
|
|
|
|
|
used to define <a href="#NAT"> static NAT</a> .</li>
|
|
|
|
|
|
<li><b> <a href="#ProxyArp">proxyarp</a></b> -- a parameter
|
|
|
|
|
|
file in /etc/shorewall used to define <a href="#ProxyArp"> Proxy
|
|
|
|
|
|
Arp</a> .</li>
|
|
|
|
|
|
<li><b><a href="#rfc1918">rfc1918</a></b> -- a parameter file
|
|
|
|
|
|
in /etc/shorewall used to define the treatment of packets under the
|
|
|
|
|
|
<a href="#Interfaces">norfc1918 interface option</a>.</li>
|
|
|
|
|
|
<li><b><a href="#Routestopped">routestopped</a></b> -- a parameter
|
|
|
|
|
|
file in /etc/shorewall used to define those hosts that can access the
|
|
|
|
|
|
firewall when Shorewall is stopped.</li>
|
|
|
|
|
|
<li><a href="traffic_shaping.htm#tcrules"><b>tcrules</b> </a>--
|
|
|
|
|
|
a parameter file in /etc/shorewall used to define rules for classifying
|
|
|
|
|
|
packets for <a href="traffic_shaping.htm">Traffic Shaping/Control</a>.</li>
|
|
|
|
|
|
<li><b> <a href="#Tunnels">tunnels</a></b> -- a parameter file
|
|
|
|
|
|
in /etc/shorewall used to define IPSec tunnels.</li>
|
|
|
|
|
|
<li><b> <a href="#Starting">shorewall</a> </b> -- a shell program
|
|
|
|
|
|
(requiring a Bourne shell or derivative) used to control and
|
|
|
|
|
|
monitor the firewall. This should be placed in /sbin or in
|
|
|
|
|
|
/usr/sbin (the install.sh script and the rpm install this file
|
|
|
|
|
|
in /sbin).</li>
|
|
|
|
|
|
<li><b> version</b> -- a file created in /etc/shorewall/
|
|
|
|
|
|
(/var/lib/shorewall in version 1.3.2-1.3.8 and /usr/lib/shorewall
|
|
|
|
|
|
beginning in version 1.3.9) that describes the version of<6F> Shorewall
|
|
|
|
|
|
installed on your system.</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h2><a name="Variables"></a> /etc/shorewall/params</h2>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>You may use the file /etc/shorewall/params file to set shell variables
|
2002-11-24 21:08:19 +01:00
|
|
|
|
that you can then use in some of the other configuration files.</p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>It is suggested that variable names begin with an upper case letter<font
|
|
|
|
|
|
size="1"> </font>to distinguish them from variables used internally
|
2002-11-24 21:08:19 +01:00
|
|
|
|
within the Shorewall programs</p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Example:</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<pre><font face="Courier"> NET_IF=eth0<br> NET_BCAST=130.252.100.255<br> NET_OPTIONS=noping,norfc1918</font></pre>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Example (/etc/shorewall/interfaces record):</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<pre> <font face="Courier">net $NET_IF $NET_BCAST $NET_OPTIONS</font></pre>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>The result will be the same as if the record had been written</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<pre> <font face="Courier">net eth0 130.252.100.255 noping,norfc1918</font></pre>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Variables may be used anywhere in the other configuration
|
2002-11-24 21:08:19 +01:00
|
|
|
|
files.</p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h2><b><a name="Zones"></a> </b>/etc/shorewall/zones</h2>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>This file is used to define the network zones. There is one entry
|
2002-11-24 21:08:19 +01:00
|
|
|
|
in /etc/shorewall/zones for each zone; Columns in an entry are:</p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b> ZONE</b> - short name for the zone. The name should
|
|
|
|
|
|
be 5 characters or less in length and consist of lower-case letters
|
|
|
|
|
|
or numbers. Short names must begin with a letter and the name assigned
|
|
|
|
|
|
to the firewall is reserved for use by Shorewall itself. Note that
|
|
|
|
|
|
the output produced by iptables is much easier to read if you select
|
|
|
|
|
|
short names that are three characters or less in length. The name
|
|
|
|
|
|
"all" may not be used as a zone name nor may the zone name assigned to
|
|
|
|
|
|
the firewall itself via the FW variable in <a href="#Conf">/etc/shorewall/shorewall.conf</a>.</li>
|
|
|
|
|
|
<li><b> DISPLAY</b> - The name of the zone as displayed during
|
|
|
|
|
|
Shorewall startup.</li>
|
|
|
|
|
|
<li><b> COMMENTS</b> - Any comments that you want to make about
|
|
|
|
|
|
the zone. Shorewall ignores these comments.</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>The /etc/shorewall/zones file released with Shorewall is as follows:</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" style="border-collapse: collapse;" cellpadding="2">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b> ZONE</b></td>
|
|
|
|
|
|
<td><b> DISPLAY</b></td>
|
|
|
|
|
|
<td><b> COMMENTS</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>net</td>
|
|
|
|
|
|
<td>Net</td>
|
|
|
|
|
|
<td>Internet</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>loc</td>
|
|
|
|
|
|
<td>Local</td>
|
|
|
|
|
|
<td>Local networks</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>dmz</td>
|
|
|
|
|
|
<td>DMZ</td>
|
|
|
|
|
|
<td>Demilitarized zone</td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
</tbody>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>You may add, delete and modify entries in the /etc/shorewall/zones file
|
2002-11-24 21:08:19 +01:00
|
|
|
|
as desired so long as you have at least one zone defined.</p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b><font size="5" color="#ff0000"> Warning 1: </font><font
|
|
|
|
|
|
color="#ff0000"> If you rename or delete a zone, you should perform "shorewall
|
2002-11-24 21:08:19 +01:00
|
|
|
|
stop; shorewall start" to install the change rather than "shorewall
|
|
|
|
|
|
restart".</font></b></p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b><font size="5" color="#ff0000">Warning 2: </font><font
|
|
|
|
|
|
color="#ff0000">The order of entries in the /etc/shorewall/zones file is
|
2002-11-24 21:08:19 +01:00
|
|
|
|
significant <a href="#Nested">in some cases</a>.</font></b></p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h2><font color="#660066"><a name="Interfaces"></a> </font>/etc/shorewall/interfaces</h2>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>This file is used to tell the firewall which of your firewall's network
|
2002-11-24 21:08:19 +01:00
|
|
|
|
interfaces are connected to which zone. There will be one entry in
|
|
|
|
|
|
/etc/shorewall/interfaces for each of your interfaces. Columns in an entry
|
|
|
|
|
|
are:</p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b> ZONE</b> - A zone defined in the <a href="#Zones">/etc/shorewall/zones</a>
|
|
|
|
|
|
file or<6F> "-". If you specify "-", you must use the <a
|
2002-09-16 19:13:10 +02:00
|
|
|
|
href="#Hosts"> /etc/shorewall/hosts</a> file to define the zones
|
2002-11-24 21:08:19 +01:00
|
|
|
|
accessed via this interface.</li>
|
|
|
|
|
|
<li><b> INTERFACE</b> - the name of the interface (examples:
|
|
|
|
|
|
eth0, ppp0, ipsec+). <font color="#ff0000"><b>D</b><b>O NOT INCLUDE THE
|
|
|
|
|
|
LOOPBACK INTERFACE (lo) IN THIS FILE!!!</b></font></li>
|
|
|
|
|
|
<li><b> BROADCAST</b> - the broadcast address(es) for the sub-network(s)
|
|
|
|
|
|
attached to the interface. This should be left empty for P-T-P interfaces
|
|
|
|
|
|
(ppp*, ippp*); if you need to specify options for such an interface,
|
|
|
|
|
|
enter "-" in this column. If you supply the special value "detect" in
|
|
|
|
|
|
this column, the firewall will automatically determine the broadcast
|
|
|
|
|
|
address. In order to use "detect":
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li>you must have iproute installed</li>
|
|
|
|
|
|
<li>the interface must be up before you start your firewall</li>
|
|
|
|
|
|
<li>the interface must only be attached to a single sub-network
|
|
|
|
|
|
(i.e., there must have a single broadcast address).<2E></li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</li>
|
|
|
|
|
|
<li><b> OPTIONS</b> - a comma-separated list of options. Possible
|
|
|
|
|
|
options include:
|
|
|
|
|
|
|
|
|
|
|
|
<p> <b>tcpflags </b>(added in version 1.3.11) - This option causes
|
|
|
|
|
|
Shorewall to make sanity checks on the header flags in TCP packets arriving
|
|
|
|
|
|
on this interface. Packets failing these checks are logged according to the
|
|
|
|
|
|
TCP_FLAGS_LOG_LEVEL option in<a href="#Conf"> /etc/shorewall/shorewall.conf</a>
|
|
|
|
|
|
and are disposed of according to the TCP_FLAGS_DISPOSITION option.<br>
|
|
|
|
|
|
<b><br>
|
|
|
|
|
|
blacklist</b> - This option causes incoming packets on this
|
|
|
|
|
|
interface to be checked against the <a href="#Blacklist">blacklist</a>.<b><br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
dhcp</b> - The interface is assigned an IP address via DHCP or
|
|
|
|
|
|
is used by a DHCP server running on the firewall. The firewall
|
|
|
|
|
|
will be configured to allow DHCP traffic to and from the interface
|
|
|
|
|
|
even when the firewall is stopped. You may also wish to use this option
|
|
|
|
|
|
if you have a static IP but you are on a LAN segment that has a lot of
|
2002-11-09 19:06:34 +01:00
|
|
|
|
Laptops that use DHCP and you select the <b>norfc1918 </b>option (see
|
|
|
|
|
|
below).</p>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> <b> noping</b> - ICMP echo-request (ping) packets addressed to
|
2002-11-24 21:08:19 +01:00
|
|
|
|
the firewall will be ignored by this interface.<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
<b>filterping </b>- ICMP echo-request (ping) packets addressed
|
|
|
|
|
|
to the firewall will be handled according to the /etc/shorewall/rules
|
|
|
|
|
|
and /etc/shorewall/policy file. If the applicable policy is DROP or REJECT
|
|
|
|
|
|
and you have supplied your own /etc/shorewall/icmpdef file then these
|
|
|
|
|
|
'ping' requests will be passed through the rules in that file before
|
|
|
|
|
|
being dropped or rejected. If neither <b>noping </b>nor <b>filterping</b>
|
|
|
|
|
|
is specified then the firewall will automatically ACCEPT these 'ping'
|
|
|
|
|
|
requests. If both <b>noping</b> and <b>filterping </b>are specified,
|
|
|
|
|
|
<b>filterping</b> takes precedence.</p>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> <b> routestopped</b> - Beginning with Shorewall 1.3.4, this option
|
2002-11-24 21:08:19 +01:00
|
|
|
|
is deprecated in favor of the <a href="#Routestopped">/etc/shorewall/routestopped</a>
|
|
|
|
|
|
file. When the firewall is stopped, traffic to and from this interface
|
|
|
|
|
|
will be accepted and routing will occur between this interface and
|
|
|
|
|
|
other <i>routestopped </i>interfaces.</p>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> <b> norfc1918</b> - Packets arriving on this interface and that
|
2002-11-24 21:08:19 +01:00
|
|
|
|
have a source address that is reserved in RFC 1918 or in other RFCs
|
|
|
|
|
|
will be dropped after being optionally logged. If <a href="#Conf">packet
|
|
|
|
|
|
mangling is enabled in /etc/shorewall/shorewall.conf</a> , then packets
|
|
|
|
|
|
arriving on this interface that have a destination address that is
|
|
|
|
|
|
reserved by one of these RFCs will also be logged and dropped.<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
Addresses blocked by the standard <a href="#rfc1918"> <b>rfc1918
|
|
|
|
|
|
</b>file</a> include those addresses reserved by RFC1918 plus other
|
|
|
|
|
|
ranges reserved by the IANA or by other RFCs.</p>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> Beware that as IPv4 addresses become in increasingly short supply,
|
2002-11-24 21:08:19 +01:00
|
|
|
|
ISPs are beginning to use RFC 1918 addresses within their own infrastructure.
|
|
|
|
|
|
Also, many cable and DSL "modems" have an RFC 1918 address that can
|
|
|
|
|
|
be used through a web browser for management and monitoring functions.
|
|
|
|
|
|
If you want to specify <b>norfc1918</b> on your external interface but
|
|
|
|
|
|
need to allow access to certain addresses from the above list, see <a
|
2002-09-16 19:13:10 +02:00
|
|
|
|
href="FAQ.htm#faq14">FAQ 14.</a></p>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> <b> routefilter</b> - Invoke the Kernel's route filtering
|
2002-11-24 21:08:19 +01:00
|
|
|
|
(anti-spoofing) facility on this interface. The kernel will reject
|
|
|
|
|
|
any packets incoming on this interface that have a source address
|
|
|
|
|
|
that would be routed outbound through another interface on the firewall.
|
|
|
|
|
|
<font color="#ff0000">Warning: </font>If you specify this option
|
|
|
|
|
|
for an interface then the interface must be up prior to starting the
|
|
|
|
|
|
firewall.</p>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> <b> multi</b> - The interface has multiple addresses and
|
2002-11-24 21:08:19 +01:00
|
|
|
|
you want to be able to route between them. Example: you have two
|
|
|
|
|
|
addresses on your single local interface eth1, one each in subnets
|
|
|
|
|
|
192.168.1.0/24 and 192.168.2.0/24 and you want to route between these
|
|
|
|
|
|
subnets. Because you only have one interface in the local zone, Shorewall
|
|
|
|
|
|
won't normally create a rule to forward packets from eth1 to eth1.
|
|
|
|
|
|
Adding "multi" to the entry for eth1 will cause Shorewall to create
|
|
|
|
|
|
the loc2loc chain and the appropriate forwarding rule.</p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b>dropunclean</b> - Packets from this interface that
|
|
|
|
|
|
are selected by the 'unclean' match target in iptables will
|
|
|
|
|
|
be <a href="#LogUnclean">optionally logged</a> and then dropped.
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<font color="#ff0000"><b>Warning: This feature
|
|
|
|
|
|
requires that UNCLEAN match support be configured in your
|
|
|
|
|
|
kernel, either in the kernel itself or as a module. UNCLEAN
|
|
|
|
|
|
support is broken in some versions of the kernel but appears
|
|
|
|
|
|
to work ok in 2.4.17-rc1.<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
Update 12/17/2001: </b></font>The unclean match
|
|
|
|
|
|
patch from 2.4.17-rc1 is <a
|
2002-09-16 19:13:10 +02:00
|
|
|
|
href="ftp://ftp.shorewall.net/pub/shorewall/misc/unclean.patch">available
|
2002-11-24 21:08:19 +01:00
|
|
|
|
for download</a>. I am currently running this patch
|
|
|
|
|
|
applied to kernel 2.4.16.</p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b><font color="#ff6633">Update 12/20/2001: </font></b>I've
|
2002-11-24 21:08:19 +01:00
|
|
|
|
seen a number of tcp connection requests with OPT
|
2002-11-09 19:06:34 +01:00
|
|
|
|
(020405B4<u>0000080A</u>...) being dropped in the
|
|
|
|
|
|
<i>badpkt</i> chain. This appears to be a bug in
|
|
|
|
|
|
the remote TCP stack whereby it is 8-byte aligning
|
|
|
|
|
|
a timestamp (TCP option 8) but rather than padding with 0x01
|
|
|
|
|
|
it is padding with 0x00. It's a tough call whether to deny
|
|
|
|
|
|
people access to your servers because of this rather minor
|
|
|
|
|
|
bug in their networking software. If you wish to disable
|
|
|
|
|
|
the check that causes these connections to be dropped,
|
|
|
|
|
|
<a href="ftp://ftp.shorewall.net/pub/shorewall/misc/unclean1.patch">here's
|
2002-09-16 19:13:10 +02:00
|
|
|
|
a kernel patch</a> against 2.4.17-rc2.</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b>logunclean </b>- This option works like <b>dropunclean</b>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
with the exception that packets selected by the 'unclean'
|
|
|
|
|
|
match target in iptables are logged <i>but not dropped</i>.
|
|
|
|
|
|
The level at which the packets are logged is determined
|
|
|
|
|
|
by the setting of <a href="#LogUnclean">LOGUNCLEAN</a>
|
|
|
|
|
|
and if LOGUNCLEAN has not been set, "info" is assumed.</p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b>proxyarp </b>(Added in version 1.3.5) - This option
|
|
|
|
|
|
causes Shorewall to set /proc/sys/net/ipv4/conf/<i><interface></i>/proxy_arp
|
2002-11-24 21:08:19 +01:00
|
|
|
|
and is used when implementing Proxy ARP Sub-netting
|
|
|
|
|
|
as described at <a
|
2002-09-16 19:13:10 +02:00
|
|
|
|
href="http://www.tldp.org/HOWTO/mini/Proxy-ARP-Subnet/">
|
|
|
|
|
|
http://www.tldp.org/HOWTO/mini/Proxy-ARP-Subnet/</a>. Do <u>
|
|
|
|
|
|
not</u> set this option if you are implementing Proxy ARP
|
|
|
|
|
|
through entries in <a href="#ProxyArp">
|
2002-11-09 19:06:34 +01:00
|
|
|
|
/etc/shorewall/proxyarp</a>.<br>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<br>
|
|
|
|
|
|
<b>maclist</b> (Added in version 1.3.10) - If this option is specified,
|
|
|
|
|
|
all connection requests from this interface are subject to <a
|
2002-11-09 19:06:34 +01:00
|
|
|
|
href="MAC_Validation.html">MAC Verification</a>. May only be specified for
|
2002-11-24 21:08:19 +01:00
|
|
|
|
ethernet interfaces.<br>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<p>Example 1: You have a conventional firewall setup in which eth0 connects
|
|
|
|
|
|
to a Cable or DSL modem and eth1 connects to your local network and
|
|
|
|
|
|
eth0 gets its IP address via DHCP. You want to ignore ping requests from
|
|
|
|
|
|
the internet and you want to check all packets entering
|
|
|
|
|
|
from the internet against the <a href="#Blacklist">black
|
|
|
|
|
|
list</a>. Your /etc/shorewall/interfaces file would be as follows:</p>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b> ZONE</b></td>
|
|
|
|
|
|
<td><b> INTERFACE</b></td>
|
|
|
|
|
|
<td><b> BROADCAST</b></td>
|
|
|
|
|
|
<td><b> OPTIONS</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>net</td>
|
|
|
|
|
|
<td>eth0</td>
|
|
|
|
|
|
<td>detect</td>
|
|
|
|
|
|
<td>dhcp,noping,norfc1918,blacklist</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>loc</td>
|
|
|
|
|
|
<td>eth1</td>
|
|
|
|
|
|
<td>detect</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</tbody>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Example 2: You have a standalone dialup GNU/Linux System. Your /etc/shorewall/interfaces
|
2002-11-24 21:08:19 +01:00
|
|
|
|
file would be:</p>
|
2002-09-29 23:42:38 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
<blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b> ZONE</b></td>
|
|
|
|
|
|
<td><b> INTERFACE</b></td>
|
|
|
|
|
|
<td><b> BROADCAST</b></td>
|
|
|
|
|
|
<td><b> OPTIONS</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>net</td>
|
|
|
|
|
|
<td>ppp0</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</tbody>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Example 3: You have local interface eth1 with two IP
|
|
|
|
|
|
addresses - 192.168.1.1/24 and 192.168.12.1/24</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
<blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<tr>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<td><b> ZONE</b></td>
|
|
|
|
|
|
<td><b> INTERFACE</b></td>
|
|
|
|
|
|
<td><b> BROADCAST</b></td>
|
|
|
|
|
|
<td><b> OPTIONS</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>loc</td>
|
|
|
|
|
|
<td>eth1</td>
|
|
|
|
|
|
<td>192.168.1.255,192.168.12.255</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
</tbody>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h2><font color="#660066"><a name="Hosts"></a> </font>/etc/shorewall/hosts
|
2002-11-24 21:08:19 +01:00
|
|
|
|
Configuration</h2>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>For most applications, specifying zones entirely in terms of network
|
|
|
|
|
|
interfaces is sufficient. There may be times though where you need to define
|
|
|
|
|
|
a zone to be a more general collection of hosts. This is the purpose of
|
|
|
|
|
|
the /etc/shorewall/hosts file.</p>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b><font color="#ff0000">WARNING: </font>90% of
|
|
|
|
|
|
Shorewall users don't need to put entries in this file and
|
|
|
|
|
|
80% of those who try to add such entries do it wrong.
|
|
|
|
|
|
Unless you are ABSOLUTELY SURE that you need entries in
|
|
|
|
|
|
this file, don't touch it.</b></p>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Columns in this file are:</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b> ZONE </b> - A zone defined in the <a href="#Zones">/etc/shorewall/zones</a>
|
|
|
|
|
|
file.</li>
|
|
|
|
|
|
<li><b> HOST(S)</b> - The name of a network interface followed
|
|
|
|
|
|
by a colon (":") followed by either:</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ol>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li>An IP address (example - eth1:192.168.1.3)</li>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li>A subnet in CIDR notation<i>
|
|
|
|
|
|
</i>(example - eth2:192.168.2.0/24)</li>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ol>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>The interface name much match an entry in /etc/shorewall/interfaces.</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b> OPTIONS</b> - A comma-separated list of options.</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b>routestopped</b> - Beginning with Shorewall
|
|
|
|
|
|
1.3.4, this option is deprecated in favor of the
|
|
|
|
|
|
<a href="#Routestopped">/etc/shorewall/routestopped</a>
|
|
|
|
|
|
file. When the firewall is stopped, traffic to and from
|
2002-11-24 21:08:19 +01:00
|
|
|
|
this host (these hosts) will be accepted and routing will occur
|
|
|
|
|
|
between this host and other <i>routestopped </i>interfaces and hosts.<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
<b>maclist - </b>Added in version 1.3.10. If specified, connection requests
|
|
|
|
|
|
from the hosts specified in this entry are subject to <a
|
2002-11-09 19:06:34 +01:00
|
|
|
|
href="MAC_Validation.html">MAC Verification</a>. This option is only valid
|
2002-11-24 21:08:19 +01:00
|
|
|
|
for ethernet interfaces.<br>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
</blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>If you don't define any hosts for a zone, the hosts in the zone default
|
2002-11-24 21:08:19 +01:00
|
|
|
|
to i0:0.0.0.0/0 , i1:0.0.0.0/0, ... where i0, i1, ... are the interfaces
|
|
|
|
|
|
to the zone.</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b><font size="4" color="#ff0000">Note 1: </font></b> You probably DON'T
|
|
|
|
|
|
want to specify any hosts for your internet zone since the hosts that
|
|
|
|
|
|
you specify will be the only ones that you will be able to access without
|
|
|
|
|
|
adding additional rules.</p>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><font color="#ff0000" size="4"><b>Note 2: </b>
|
|
|
|
|
|
</font> The setting of the MERGE_HOSTS variable
|
2002-11-24 21:08:19 +01:00
|
|
|
|
in <a href="#Conf">/etc/shorewall/shorewall.conf</a>
|
|
|
|
|
|
has an important effect on how the host file
|
|
|
|
|
|
is processed. Please read the description of
|
|
|
|
|
|
that variable carefully.</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Example:</p>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Your local interface is eth1 and you have two groups of local hosts that
|
2002-11-24 21:08:19 +01:00
|
|
|
|
you want to make into separate zones:</p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li>192.168.1.0/25<32></li>
|
|
|
|
|
|
<li>192.168.1.128/25</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> Your /etc/shorewall/interfaces file might look like:</p>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
<blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b> ZONE</b></td>
|
|
|
|
|
|
<td><b> INTERFACE</b></td>
|
|
|
|
|
|
<td><b> BROADCAST</b></td>
|
|
|
|
|
|
<td><b> OPTIONS</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>net</td>
|
|
|
|
|
|
<td>eth0</td>
|
|
|
|
|
|
<td>detect</td>
|
|
|
|
|
|
<td>dhcp,noping,norfc1918</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>-</td>
|
|
|
|
|
|
<td>eth1</td>
|
|
|
|
|
|
<td>detect</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</tbody>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> The '-' in the ZONE column for eth1 tells Shorewall that eth1 interfaces
|
2002-11-24 21:08:19 +01:00
|
|
|
|
to multiple zones.</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> Your /etc/shorewall/hosts file might look like:</p>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote> <font
|
|
|
|
|
|
face="Century Gothic, Arial, Helvetica">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</font>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b> ZONE</b></td>
|
|
|
|
|
|
<td><b> HOST(S)</b></td>
|
|
|
|
|
|
<td><b> OPTIONS</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>loc1</td>
|
|
|
|
|
|
<td>eth1:192.168.1.0/25</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>loc2</td>
|
|
|
|
|
|
<td>eth1:192.168.1.128/25</td>
|
|
|
|
|
|
<td>routestopped</td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</tbody>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> Hosts in 'loc2' can communicate with the firewall while Shorewall is
|
2002-11-24 21:08:19 +01:00
|
|
|
|
stopped -- those in 'loc1' cannot.</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h4><font color="#660066"><a name="Nested"></a> Nested and Overlapping Zones</font></h4>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> The /etc/shorewall/interfaces and /etc/shorewall/hosts file allow
|
|
|
|
|
|
you to define nested or overlapping zones. Such overlapping/nested zones
|
2002-11-24 21:08:19 +01:00
|
|
|
|
are allowed and Shorewall processes zones in the order that they appear
|
|
|
|
|
|
in the /etc/shorewall/zones file. So if you have nested zones, you want
|
|
|
|
|
|
the sub-zone to appear before the super-zone and in the case of overlapping
|
|
|
|
|
|
zones, the rules that will apply to hosts that belong to both zones
|
|
|
|
|
|
is determined by which zone appears first in /etc/shorewall/zones.</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> Hosts that belong to more than one zone may be managed by the rules
|
2002-11-24 21:08:19 +01:00
|
|
|
|
of all of those zones. This is done through use of the special <a
|
2002-09-16 19:13:10 +02:00
|
|
|
|
href="#CONTINUE">CONTINUE policy</a> described below.</p>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h2><font color="#660066"><a name="Policy"></a>
|
|
|
|
|
|
</font>/etc/shorewall/policy Configuration.</h2>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>This file is used to describe the firewall policy regarding establishment
|
2002-11-24 21:08:19 +01:00
|
|
|
|
of connections. Connection establishment is described in terms of <i>clients</i>
|
|
|
|
|
|
who initiate connections and <i> servers </i>who receive those connection
|
|
|
|
|
|
requests. Policies defined in /etc/shorewall/policy describe which zones
|
|
|
|
|
|
are allowed to establish connections with other zones.</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Policies established in /etc/shorewall/policy can be viewed as default
|
2002-11-24 21:08:19 +01:00
|
|
|
|
policies. If no rule in /etc/shorewall/rules applies to a particular
|
|
|
|
|
|
connection request then the policy from /etc/shorewall/policy is applied.</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Four policies are defined:</p>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b> ACCEPT</b> - The connection is allowed.</li>
|
|
|
|
|
|
<li><b> DROP</b> - The connection request is ignored.</li>
|
|
|
|
|
|
<li><b> REJECT</b> - The connection request is rejected with
|
|
|
|
|
|
an RST (TCP) or an ICMP destination-unreachable packet being returned
|
|
|
|
|
|
to the client.</li>
|
|
|
|
|
|
<li><b> CONTINUE </b> - The connection is neither ACCEPTed,
|
|
|
|
|
|
DROPped nor REJECTed. CONTINUE may be used when one or both of the
|
|
|
|
|
|
zones named in the entry are sub-zones of or intersect with another
|
|
|
|
|
|
zone. For more information, see below.<2E></li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> For each policy specified in /etc/shorewall/policy, you can indicate
|
2002-11-24 21:08:19 +01:00
|
|
|
|
that you want a message sent to your system log each time that the policy
|
2002-11-09 19:06:34 +01:00
|
|
|
|
is applied.</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> Entries in /etc/shorewall/policy have four columns as follows:</p>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ol>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li> <b> SOURCE</b> - The name of
|
|
|
|
|
|
a client zone (a zone defined in the <a href="#Zones"> /etc/shorewall/zones
|
|
|
|
|
|
file</a> , the <a href="#Conf">name of the firewall zone</a> or
|
|
|
|
|
|
"all").</li>
|
|
|
|
|
|
|
|
|
|
|
|
<li> <b> DEST</b> - The name of a
|
|
|
|
|
|
destination zone (a zone defined in the <a href="#Zones"> /etc/shorewall/zones
|
|
|
|
|
|
file</a> , the <a href="#Conf">name of the firewall zone</a> or "all").
|
|
|
|
|
|
Shorewall automatically allows all traffic from the firewall to itself so
|
|
|
|
|
|
the <a href="#Conf">name of the firewall zone</a> cannot appear in both the
|
|
|
|
|
|
SOURCE and DEST columns.</li>
|
|
|
|
|
|
|
|
|
|
|
|
<li> <b> POLICY</b> - The default
|
|
|
|
|
|
policy for connection requests from the SOURCE zone to the DESTINATION
|
|
|
|
|
|
zone.</li>
|
|
|
|
|
|
|
|
|
|
|
|
<li> <b> LOG LEVEL</b> - Optional.
|
|
|
|
|
|
If left empty, no log message is generated when the policy is applied.
|
|
|
|
|
|
Otherwise, this column should contain an integer or name indicating
|
|
|
|
|
|
a syslog level. See the syslog.conf man page for a description of
|
|
|
|
|
|
each log level.</li>
|
|
|
|
|
|
|
|
|
|
|
|
<li> <b>LIMIT:BURST </b>- Optional.
|
|
|
|
|
|
If left empty, TCP connection requests from the <b>SOURCE</b> zone
|
|
|
|
|
|
to the <b>DEST</b> zone will not be rate-limited. Otherwise, this
|
|
|
|
|
|
column specifies the maximum rate at which TCP connection requests will
|
|
|
|
|
|
be accepted followed by a colon (":") followed by the maximum burst size
|
|
|
|
|
|
that will be tolerated. Example: <b> 10/sec:40</b> specifies that
|
|
|
|
|
|
the maximum rate of TCP connection requests allowed will be 10 per second
|
|
|
|
|
|
and a burst of 40 connections will be tolerated. Connection requests in
|
|
|
|
|
|
excess of these limits will be dropped.</li>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ol>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> In the SOURCE and DEST columns, you can enter "all" to indicate all
|
2002-11-24 21:08:19 +01:00
|
|
|
|
zones.<2E></p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> The policy file installed by default is as follows:</p>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote> <font
|
|
|
|
|
|
face="Century Gothic, Arial, Helvetica">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</font>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b>SOURCE</b></td>
|
|
|
|
|
|
<td><b>DEST</b></td>
|
|
|
|
|
|
<td><b> POLICY</b></td>
|
|
|
|
|
|
<td><b> LOG LEVEL</b></td>
|
|
|
|
|
|
<td><b>LIMIT:BURST</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>loc</td>
|
|
|
|
|
|
<td>net</td>
|
|
|
|
|
|
<td>ACCEPT</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<td><EFBFBD></td>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>net</td>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>DROP</td>
|
|
|
|
|
|
<td>info</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>REJECT</td>
|
|
|
|
|
|
<td>info</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</tbody>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> This table may be interpreted as follows:</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li>All connection requests from the local network to hosts on
|
|
|
|
|
|
the internet are accepted.</li>
|
|
|
|
|
|
<li>All connection requests originating from the internet are
|
|
|
|
|
|
ignored and logged at level KERNEL.INFO.</li>
|
|
|
|
|
|
<li>All other connection requests are rejected and logged.</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b><font size="4" color="#ff0000"> WARNING:</font></b></p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><font color="#ff0000"><b> The firewall script processes</b> <b><EFBFBD>the
|
2002-11-24 21:08:19 +01:00
|
|
|
|
/etc/shorewall/policy file from top to bottom and <u>uses the first
|
|
|
|
|
|
applicable policy that it finds.</u> For example, in the following
|
|
|
|
|
|
policy file, the policy for (loc, loc) connections would be ACCEPT as
|
|
|
|
|
|
specified in the first entry even though the third entry in the file specifies
|
|
|
|
|
|
REJECT.</b></font></p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote> <font
|
2002-11-09 19:06:34 +01:00
|
|
|
|
face="Century Gothic, Arial, Helvetica"> </font>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b>SOURCE</b></td>
|
|
|
|
|
|
<td><b>DEST</b></td>
|
|
|
|
|
|
<td><b>POLICY</b></td>
|
|
|
|
|
|
<td><b>LOG LEVEL</b></td>
|
|
|
|
|
|
<td><b>LIMIT:BURST</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>loc</td>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>ACCEPT</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>net</td>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>DROP</td>
|
|
|
|
|
|
<td>info</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>loc</td>
|
|
|
|
|
|
<td>loc</td>
|
|
|
|
|
|
<td>REJECT</td>
|
|
|
|
|
|
<td>info</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-09-29 23:42:38 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</tbody>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
|
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<h4><font color="#660066"><a name="CONTINUE"></a>
|
|
|
|
|
|
The CONTINUE policy</font></h4>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<p> Where zones are <a href="#Nested">nested or overlapping</a> , the
|
2002-11-24 21:08:19 +01:00
|
|
|
|
CONTINUE policy allows hosts that are within multiple zones to be managed
|
|
|
|
|
|
under the rules of all of these zones. Let's look at an example:</p>
|
|
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<p> /etc/shorewall/zones:</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
<blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b> ZONE</b></td>
|
|
|
|
|
|
<td><b> DISPLAY</b></td>
|
|
|
|
|
|
<td><b> COMMENTS</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>sam</td>
|
|
|
|
|
|
<td>Sam</td>
|
|
|
|
|
|
<td>Sam's system at home</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>net</td>
|
|
|
|
|
|
<td>Internet</td>
|
|
|
|
|
|
<td>The Internet</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>loc</td>
|
|
|
|
|
|
<td>Loc</td>
|
|
|
|
|
|
<td>Local Network</td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-09-29 23:42:38 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</tbody>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
|
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<p> /etc/shorewall/interfaces:</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
<blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b> ZONE</b></td>
|
|
|
|
|
|
<td><b> INTERFACE</b></td>
|
|
|
|
|
|
<td><b> BROADCAST</b></td>
|
|
|
|
|
|
<td><b> OPTIONS</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>-</td>
|
|
|
|
|
|
<td>eth0</td>
|
|
|
|
|
|
<td>detect</td>
|
|
|
|
|
|
<td>dhcp,noping,norfc1918</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>loc</td>
|
|
|
|
|
|
<td>eth1</td>
|
|
|
|
|
|
<td>detect</td>
|
|
|
|
|
|
<td>routestopped</td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</tbody>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
|
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<p> /etc/shorewall/hosts:</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<blockquote> <font
|
|
|
|
|
|
face="Century Gothic, Arial, Helvetica"> </font>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b> ZONE</b></td>
|
|
|
|
|
|
<td><b> HOST(S)</b></td>
|
|
|
|
|
|
<td><b> OPTIONS</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>net</td>
|
|
|
|
|
|
<td>eth0:0.0.0.0/0</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>sam</td>
|
|
|
|
|
|
<td>eth0:206.191.149.197</td>
|
|
|
|
|
|
<td>routestopped</td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</tbody>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
|
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<p> Note that Sam's home system is a member of both the <b>sam</b> zone
|
2002-11-24 21:08:19 +01:00
|
|
|
|
and the <b>net</b> zone and <a
|
2002-11-09 19:06:34 +01:00
|
|
|
|
href="#Nested"> as described above</a> , that means that <b>sam</b> must
|
|
|
|
|
|
be listed before <b>net</b><EFBFBD> in /etc/shorewall/zones.</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<p> /etc/shorewall/policy:</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<blockquote> <font
|
2002-09-16 19:13:10 +02:00
|
|
|
|
face="Century Gothic, Arial, Helvetica"> </font><font
|
2002-11-09 19:06:34 +01:00
|
|
|
|
face="Century Gothic, Arial, Helvetica"> </font>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b> SOURCE</b></td>
|
|
|
|
|
|
<td><b> DEST</b></td>
|
|
|
|
|
|
<td><b> POLICY</b></td>
|
|
|
|
|
|
<td><b> LOG LEVEL</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>loc</td>
|
|
|
|
|
|
<td>net</td>
|
|
|
|
|
|
<td>ACCEPT</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>sam</td>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>CONTINUE</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>net</td>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>DROP</td>
|
|
|
|
|
|
<td>info</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>REJECT</td>
|
|
|
|
|
|
<td>info</td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
</tbody>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
|
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<p> The second entry above says that when Sam is the client, connection
|
2002-11-24 21:08:19 +01:00
|
|
|
|
requests should first be process under rules where the source zone is
|
|
|
|
|
|
<b>sam</b> and if there is no match then the connection request should be
|
|
|
|
|
|
treated under rules where the source zone is <b>net</b>. It is important
|
|
|
|
|
|
that this policy be listed BEFORE the next policy (<b>net</b> to <b>all</b>).</p>
|
|
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<p> Partial /etc/shorewall/rules:</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<blockquote> <font
|
|
|
|
|
|
face="Century Gothic, Arial, Helvetica"> </font><font
|
|
|
|
|
|
face="Century Gothic, Arial, Helvetica"> </font>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b>ACTION</b></td>
|
|
|
|
|
|
<td><b>SOURCE</b></td>
|
|
|
|
|
|
<td><b>DEST</b></td>
|
|
|
|
|
|
<td><b> PROTO</b></td>
|
|
|
|
|
|
<td><b>DEST<br>
|
|
|
|
|
|
PORT(S)</b></td>
|
|
|
|
|
|
<td><b>SOURCE<br>
|
|
|
|
|
|
PORT(S)</b></td>
|
|
|
|
|
|
<td><b>ORIGINAL<br>
|
|
|
|
|
|
DEST</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>...</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>DNAT</td>
|
|
|
|
|
|
<td>sam</td>
|
|
|
|
|
|
<td>loc:192.168.1.3</td>
|
|
|
|
|
|
<td>tcp</td>
|
|
|
|
|
|
<td>ssh</td>
|
|
|
|
|
|
<td>-</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>DNAT</td>
|
|
|
|
|
|
<td>net</td>
|
|
|
|
|
|
<td>loc:192.168.1.5</td>
|
|
|
|
|
|
<td>tcp</td>
|
|
|
|
|
|
<td>www</td>
|
|
|
|
|
|
<td>-</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>...</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
</tbody>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
|
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<p> Given these two rules, Sam can connect to the firewall's internet interface
|
2002-11-24 21:08:19 +01:00
|
|
|
|
with ssh and the connection request will be forwarded to 192.168.1.3.
|
|
|
|
|
|
Like all hosts in the <b>net</b> zone, Sam can connect to the firewall's
|
|
|
|
|
|
internet interface on TCP port 80 and the connection request will be forwarded
|
|
|
|
|
|
to 192.168.1.5. The order of the rules is not significant.</p>
|
|
|
|
|
|
|
|
|
|
|
|
<p> <a name="Exclude"></a>Sometimes it is necessary to suppress port forwarding
|
|
|
|
|
|
for a sub-zone. For example, suppose that all hosts can SSH to the firewall
|
|
|
|
|
|
and be forwarded to 192.168.1.5 EXCEPT Sam. When Sam connects to the
|
|
|
|
|
|
firewall's external IP, he should be connected to the firewall itself.
|
|
|
|
|
|
Because of the way that Netfilter is constructed, this requires two
|
|
|
|
|
|
rules as follows:</p>
|
|
|
|
|
|
|
|
|
|
|
|
<blockquote>
|
|
|
|
|
|
|
|
|
|
|
|
<p> <20></p>
|
|
|
|
|
|
<font
|
|
|
|
|
|
face="Century Gothic, Arial, Helvetica"> </font><font
|
|
|
|
|
|
face="Century Gothic, Arial, Helvetica"> </font>
|
|
|
|
|
|
|
|
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
|
|
|
|
|
<tbody>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<tr>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<td><b>ACTION</b></td>
|
|
|
|
|
|
<td><b>SOURCE</b></td>
|
|
|
|
|
|
<td><b>DEST</b></td>
|
|
|
|
|
|
<td><b> PROTO</b></td>
|
|
|
|
|
|
<td><b>DEST<br>
|
|
|
|
|
|
PORT(S)</b></td>
|
|
|
|
|
|
<td><b>SOURCE<br>
|
|
|
|
|
|
PORT(S)</b></td>
|
|
|
|
|
|
<td><b>ORIGINAL<br>
|
|
|
|
|
|
DEST</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>...</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>DNAT</td>
|
|
|
|
|
|
<td>sam</td>
|
|
|
|
|
|
<td>fw</td>
|
|
|
|
|
|
<td>tcp</td>
|
|
|
|
|
|
<td>ssh</td>
|
|
|
|
|
|
<td>-</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>DNAT</td>
|
|
|
|
|
|
<td>net!sam</td>
|
|
|
|
|
|
<td>loc:192.168.1.3</td>
|
|
|
|
|
|
<td>tcp</td>
|
|
|
|
|
|
<td>ssh</td>
|
|
|
|
|
|
<td>-</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>...</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
</tbody>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>The first rule allows Sam SSH
|
|
|
|
|
|
access to the firewall. The second
|
|
|
|
|
|
rule says that any clients from the
|
|
|
|
|
|
net zone with the exception of those
|
|
|
|
|
|
in the 'sam' zone should have their
|
|
|
|
|
|
connection port forwarded to
|
|
|
|
|
|
192.168.1.3. If you need to exclude
|
|
|
|
|
|
more than one zone in this way,
|
2002-11-24 21:08:19 +01:00
|
|
|
|
you can list the zones separated
|
|
|
|
|
|
by commas (e.g., net!sam,joe,fred).
|
|
|
|
|
|
This technique also may be
|
|
|
|
|
|
used when the ACTION is REDIRECT.</p>
|
2002-09-29 23:42:38 +02:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h2><font color="#660066"><a name="Rules"></a>
|
|
|
|
|
|
</font>/etc/shorewall/rules</h2>
|
|
|
|
|
|
|
2002-09-29 23:42:38 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>The /etc/shorewall/rules file defines exceptions to the policies established
|
2002-11-24 21:08:19 +01:00
|
|
|
|
in the /etc/shorewall/policy file. There is one entry in /etc/shorewall/rules
|
|
|
|
|
|
for each of these rules.<2E><br>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>Shorewall automatically enables firewall->firewall traffic over the
|
|
|
|
|
|
loopback interface (lo) -- that traffic cannot be regulated using rules and
|
|
|
|
|
|
any rule that tries to regulate such traffic will generate a warning and
|
|
|
|
|
|
will be ignored.<br>
|
|
|
|
|
|
</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-09-29 23:42:38 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Entries in the file have the following columns:</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b>ACTION</b>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li>ACCEPT, DROP or REJECT. These have the same meaning here
|
|
|
|
|
|
as in the policy file above.</li>
|
|
|
|
|
|
<li>DNAT -- Causes the connection request to be forwarded to
|
|
|
|
|
|
the system specified in the DEST column (port forwarding). "DNAT"
|
|
|
|
|
|
stands for "<u>D</u>estination <u>N</u>etwork <u>A</u>ddress <u>T</u>ranslation"</li>
|
|
|
|
|
|
<li>REDIRECT -- Causes the connection request to be redirected
|
|
|
|
|
|
to a port on the local (firewall) system.</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>The ACTION may optionally be followed by ":" and a syslogd log
|
2002-11-24 21:08:19 +01:00
|
|
|
|
level (example: REJECT:info). This causes the packet to be logged at
|
|
|
|
|
|
the specified level prior to being processed according to the specified
|
|
|
|
|
|
ACTION.<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
The use of DNAT or REDIRECT requires that you have <a
|
2002-09-16 19:13:10 +02:00
|
|
|
|
href="#NatEnabled">NAT enabled</a>.<br>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<20> </p>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li><b>SOURCE</b> - Describes the source hosts to which the rule
|
|
|
|
|
|
applies.. The contents of this field must begin with the name of
|
|
|
|
|
|
a zone defined in /etc/shorewall/zones, $FW or "all". If the ACTION
|
|
|
|
|
|
is DNAT or REDIRECT, sub-zones may be excluded from the rule by following
|
|
|
|
|
|
the initial zone name with "!' and a comma-separated list of those
|
|
|
|
|
|
sub-zones to be excluded. There is an <a href="#Exclude">example</a> above.<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
If the source is not 'all' then the source may be further restricted
|
|
|
|
|
|
by adding a colon (":") followed by a comma-separated list of qualifiers.
|
|
|
|
|
|
Qualifiers are may include:
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li>An interface name - refers to any connection requests arriving
|
|
|
|
|
|
on the specified interface (example loc:eth4). Beginning with
|
|
|
|
|
|
Shorwall 1.3.9, the interface name may optionally be followed by a colon
|
|
|
|
|
|
(":") and an IP address or subnet (examples: loc:eth4:192.168.4.22, net:eth0:192.0.2.0/24).</li>
|
|
|
|
|
|
<li>An IP address - refers to a connection request from the
|
|
|
|
|
|
host with the specified address (example net:155.186.235.151).
|
|
|
|
|
|
If the ACTION is DNAT, this must not be a DNS name.</li>
|
|
|
|
|
|
<li>A MAC Address in <a href="#MAC">Shorewall format</a>.</li>
|
|
|
|
|
|
<li>A subnet - refers to a connection request from any host
|
|
|
|
|
|
in the specified subnet (example net:155.186.235.0/24).</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</li>
|
|
|
|
|
|
<li><b>DEST</b> - Describes the destination host(s) to which the
|
|
|
|
|
|
rule applies. May take any of the forms described above for SOURCE
|
|
|
|
|
|
plus the following two additional forms:
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li>An IP address followed by a colon and the port <u>number</u>
|
|
|
|
|
|
that the server is listening on (service names from /etc/services
|
|
|
|
|
|
are not allowed - example loc:192.168.1.3:80). <br>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li>A single port number (again, service names are not allowed)
|
|
|
|
|
|
-- this form is only allowed if the ACTION is REDIRECT and refers
|
|
|
|
|
|
to a server running on the firewall itself and listening on the
|
|
|
|
|
|
specified port.<br>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</li>
|
|
|
|
|
|
<li><b> PROTO</b> - Protocol. Must be a protocol name from /etc/protocols,
|
|
|
|
|
|
a number, "all" or "related". Specifies the protocol of the connection
|
|
|
|
|
|
request. "related" should be specified only if you have given ALLOWRELATED="no"
|
|
|
|
|
|
in /etc/shorewall/shorewall.conf and you wish to override that setting
|
|
|
|
|
|
for related connections originating with the client(s) and server(s)
|
|
|
|
|
|
specified in this rule. When "related" is given for the protocol,
|
|
|
|
|
|
the remainder of the columns should be left blank.</li>
|
|
|
|
|
|
<li><b> DEST PORT(S)</b> - Port or port range (<low port>:<high
|
|
|
|
|
|
port>) being connected to. May only be specified if the protocol
|
|
|
|
|
|
is tcp, udp or icmp. For icmp, this column's contents are interpreted
|
|
|
|
|
|
as an icmp type. If you don't want to specify DEST PORT(S) but need
|
|
|
|
|
|
to include information in one of the columns to the right, enter
|
|
|
|
|
|
"-" in this column. You may give a list of ports and/or port ranges
|
|
|
|
|
|
separated by commas. Port numbers may be either integers or service names
|
|
|
|
|
|
from /etc/services.</li>
|
|
|
|
|
|
<li><b> SOURCE</b> <b>PORTS(S) </b>- May be used to restrict
|
|
|
|
|
|
the rule to a particular client port or port range (a port range is
|
|
|
|
|
|
specified as <low port number>:<high port number>). If
|
2002-11-09 19:06:34 +01:00
|
|
|
|
you don't want to restrict client ports but want to specify something
|
|
|
|
|
|
in the next column, enter "-" in this column. If you wish to specify
|
|
|
|
|
|
a list of port number or ranges, separate the list elements with commas
|
2002-11-24 21:08:19 +01:00
|
|
|
|
(with no embedded white space). Port numbers may be either integers
|
2002-11-09 19:06:34 +01:00
|
|
|
|
or service names from /etc/services.</li>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b>ORIGINAL DEST</b> - This column may only be non-empty if
|
|
|
|
|
|
the ACTION is DNAT or REDIRECT.<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
If DNAT or REDIRECT is the ACTION and the ORIGINAL DEST column
|
|
|
|
|
|
is left empty, any connection request arriving at the firewall from
|
|
|
|
|
|
the SOURCE that matches the rule will be forwarded or redirected. This
|
|
|
|
|
|
works fine for connection requests arriving from the internet where
|
|
|
|
|
|
the firewall has only a single external IP address. When the firewall
|
|
|
|
|
|
has multiple external IP addresses or when the SOURCE is other than
|
|
|
|
|
|
the internet, there will usually be a desire for the rule to only apply
|
|
|
|
|
|
to those connection requests directed to a particular IP address (see
|
|
|
|
|
|
Example 2 below for another usage). That IP address (or a comma-separated
|
|
|
|
|
|
list of such addresses) is specified in the ORIGINAL DEST column.<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
The IP address may be optionally followed by ":" and a second
|
|
|
|
|
|
IP address. This latter address, if present, is used as the source
|
|
|
|
|
|
address for packets forwarded to the server (This is called "Source NAT"
|
2002-11-09 19:06:34 +01:00
|
|
|
|
or SNAT).<br>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<br>
|
|
|
|
|
|
<b><font
|
2002-09-16 19:13:10 +02:00
|
|
|
|
color="#ff6633">Note:<3A> </font> When using SNAT, it is a good idea to qualify
|
|
|
|
|
|
the source with an IP address or subnet. Otherwise, it is likely that
|
|
|
|
|
|
SNAT will occur on connections other than those described in the rule.
|
|
|
|
|
|
The reason for this is that SNAT occurs in the Netfilter POSTROUTING hook
|
|
|
|
|
|
where it is not possible to restrict the scope of a rule by incoming interface.
|
|
|
|
|
|
<br>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<br>
|
|
|
|
|
|
</b>Example: DNAT<41><54><EFBFBD><EFBFBD> loc<u>:192.168.1.0/24</u><EFBFBD><EFBFBD><EFBFBD> loc:192.168.1.3<EFBFBD><EFBFBD><EFBFBD>
|
|
|
|
|
|
tcp<63><70><EFBFBD> www<77><77><EFBFBD> -<2D><><EFBFBD> 206.124.146.179:192.168.1.3<b><br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
</b>If SNAT is not used (no ":" and second IP address),
|
|
|
|
|
|
the original source address is used. If you want any destination
|
|
|
|
|
|
address to match the rule but want to specify SNAT, simply use a colon
|
|
|
|
|
|
followed by the SNAT address.</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b> <font face="Century Gothic, Arial, Helvetica"> <a
|
|
|
|
|
|
name="PortForward"></a> </font>Example 1. </b> You wish to forward all
|
2002-11-24 21:08:19 +01:00
|
|
|
|
ssh connection requests from the internet to local system 192.168.1.3.<2E></p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote> <font
|
2002-11-09 19:06:34 +01:00
|
|
|
|
face="Century Gothic, Arial, Helvetica"> </font>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b>ACTION</b></td>
|
|
|
|
|
|
<td><b>SOURCE</b></td>
|
|
|
|
|
|
<td><b>DEST</b></td>
|
|
|
|
|
|
<td><b> PROTO</b></td>
|
|
|
|
|
|
<td><b>DEST<br>
|
|
|
|
|
|
PORT(S)</b></td>
|
|
|
|
|
|
<td><b>SOURCE<br>
|
|
|
|
|
|
PORT(S)</b></td>
|
|
|
|
|
|
<td><b>ORIGINAL<br>
|
|
|
|
|
|
DEST</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>DNAT</td>
|
|
|
|
|
|
<td>net</td>
|
|
|
|
|
|
<td>loc:192.168.1.3</td>
|
|
|
|
|
|
<td>tcp</td>
|
|
|
|
|
|
<td>ssh</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</tbody>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b> Example 2. </b> You want to redirect all local www connection requests
|
2002-11-24 21:08:19 +01:00
|
|
|
|
EXCEPT those to your own
|
|
|
|
|
|
http server (206.124.146.177)
|
|
|
|
|
|
to a Squid transparent
|
|
|
|
|
|
proxy running on the firewall and listening on port 3128. Squid will
|
|
|
|
|
|
of course require access to remote web servers. This example shows yet
|
|
|
|
|
|
another use for the ORIGINAL
|
|
|
|
|
|
DEST column; here, connection
|
|
|
|
|
|
requests that were NOT
|
|
|
|
|
|
<a href="#GettingStarted">
|
|
|
|
|
|
(notice the "!")</a> originally
|
|
|
|
|
|
destined to 206.124.146.177
|
|
|
|
|
|
are redirected to local
|
|
|
|
|
|
port 3128.</p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote> <font
|
2002-11-09 19:06:34 +01:00
|
|
|
|
face="Century Gothic, Arial, Helvetica"> </font>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b>ACTION</b></td>
|
|
|
|
|
|
<td><b>SOURCE</b></td>
|
|
|
|
|
|
<td><b>DEST</b></td>
|
|
|
|
|
|
<td><b> PROTO</b></td>
|
|
|
|
|
|
<td><b>DEST<br>
|
|
|
|
|
|
PORT(S)</b></td>
|
|
|
|
|
|
<td><b>SOURCE<br>
|
|
|
|
|
|
PORT(S)</b></td>
|
|
|
|
|
|
<td><b>ORIGINAL<br>
|
|
|
|
|
|
DEST</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>REDIRECT</td>
|
|
|
|
|
|
<td>loc</td>
|
|
|
|
|
|
<td>3128</td>
|
|
|
|
|
|
<td>tcp</td>
|
|
|
|
|
|
<td>www</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td>!206.124.146.177</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>ACCEPT</td>
|
|
|
|
|
|
<td>fw</td>
|
|
|
|
|
|
<td>net</td>
|
|
|
|
|
|
<td>tcp</td>
|
|
|
|
|
|
<td>www</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</tbody>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b> Example 3. </b> You want to run a web server at 155.186.235.222 in
|
|
|
|
|
|
your DMZ and have it accessible remotely and locally. the DMZ is managed
|
2002-11-24 21:08:19 +01:00
|
|
|
|
by Proxy ARP or by classical sub-netting.</p>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote> <font
|
|
|
|
|
|
face="Century Gothic, Arial, Helvetica"> </font><font
|
2002-11-09 19:06:34 +01:00
|
|
|
|
face="Century Gothic, Arial, Helvetica"> </font>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b>ACTION</b></td>
|
|
|
|
|
|
<td><b>SOURCE</b></td>
|
|
|
|
|
|
<td><b>DEST</b></td>
|
|
|
|
|
|
<td><b> PROTO</b></td>
|
|
|
|
|
|
<td><b>DEST<br>
|
|
|
|
|
|
PORT(S)</b></td>
|
|
|
|
|
|
<td><b>SOURCE<br>
|
|
|
|
|
|
PORT(S)</b></td>
|
|
|
|
|
|
<td><b>ORIGINAL<br>
|
|
|
|
|
|
DEST</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>ACCEPT</td>
|
|
|
|
|
|
<td>net</td>
|
|
|
|
|
|
<td>dmz:155.186.235.222</td>
|
|
|
|
|
|
<td>tcp</td>
|
|
|
|
|
|
<td>www</td>
|
|
|
|
|
|
<td>-</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tr>
|
|
|
|
|
|
<td>ACCEPT</td>
|
|
|
|
|
|
<td>loc</td>
|
|
|
|
|
|
<td>dmz:155.186.235.222</td>
|
|
|
|
|
|
<td>tcp</td>
|
|
|
|
|
|
<td>www</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</tbody>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-09-29 23:42:38 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b> Example 4. </b> You want to run wu-ftpd on 192.168.2.2 in your masqueraded
|
2002-11-24 21:08:19 +01:00
|
|
|
|
DMZ. Your internet interface address is 155.186.235.151 and you want
|
|
|
|
|
|
the FTP server to be accessible from the internet in addition to the
|
|
|
|
|
|
local 192.168.1.0/24 and dmz 192.168.2.0/24 subnetworks. Note that since
|
2002-11-09 19:06:34 +01:00
|
|
|
|
the server is in the 192.168.2.0/24 subnetwork, we can assume that access
|
|
|
|
|
|
to the server from that subnet will not involve the firewall (<a
|
|
|
|
|
|
href="FAQ.htm#faq2">but see FAQ 2</a>). Note that unless you
|
|
|
|
|
|
have more than one external
|
|
|
|
|
|
IP address, you can leave
|
|
|
|
|
|
the ORIGINAL DEST
|
|
|
|
|
|
column blank in the
|
|
|
|
|
|
first rule. You cannot
|
|
|
|
|
|
leave it blank in the
|
|
|
|
|
|
second rule though because
|
|
|
|
|
|
then <u>all ftp connections</u>
|
|
|
|
|
|
originating in the local
|
|
|
|
|
|
subnet 192.168.1.0/24 would
|
|
|
|
|
|
be sent to 192.168.2.2 <u>
|
|
|
|
|
|
regardless of the site that
|
|
|
|
|
|
the user was trying to
|
|
|
|
|
|
connect to</u>. That is
|
|
|
|
|
|
clearly not what you
|
|
|
|
|
|
want <img border="0"
|
2002-09-16 19:13:10 +02:00
|
|
|
|
src="images/SY00079.gif" width="20" height="20" align="top">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
.</p>
|
2002-09-29 23:42:38 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote> <font
|
|
|
|
|
|
face="Century Gothic, Arial, Helvetica"> </font><font
|
2002-11-09 19:06:34 +01:00
|
|
|
|
face="Century Gothic, Arial, Helvetica"> </font>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b>ACTION</b></td>
|
|
|
|
|
|
<td><b>SOURCE</b></td>
|
|
|
|
|
|
<td><b>DEST</b></td>
|
|
|
|
|
|
<td><b> PROTO</b></td>
|
|
|
|
|
|
<td><b>DEST<br>
|
|
|
|
|
|
PORT(S)</b></td>
|
|
|
|
|
|
<td><b>SOURCE<br>
|
|
|
|
|
|
PORT(S)</b></td>
|
|
|
|
|
|
<td><b>ORIGINAL<br>
|
|
|
|
|
|
DEST</b></td>
|
|
|
|
|
|
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>DNAT</td>
|
|
|
|
|
|
<td>net</td>
|
|
|
|
|
|
<td>dmz:192.168.2.2</td>
|
|
|
|
|
|
<td>tcp</td>
|
|
|
|
|
|
<td>ftp</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>DNAT</td>
|
|
|
|
|
|
<td>loc:192.168.1.0/24</td>
|
|
|
|
|
|
<td>dmz:192.168.2.2</td>
|
|
|
|
|
|
<td>tcp</td>
|
|
|
|
|
|
<td>ftp</td>
|
|
|
|
|
|
<td>-</td>
|
|
|
|
|
|
<td>155.186.235.151</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
</tbody>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>If you are running wu-ftpd, you should restrict the range of passive
|
|
|
|
|
|
in your /etc/ftpaccess file. I only need a few simultaneous FTP sessions
|
2002-11-24 21:08:19 +01:00
|
|
|
|
so I use port range 65500-65535. In /etc/ftpaccess, this entry is appropriate:</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> passive ports<74> 0.0.0.0/0 65500 65534</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>If you are running pure-ftpd, you would include "-p 65500:65534" on
|
2002-11-24 21:08:19 +01:00
|
|
|
|
the pure-ftpd runline.</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>The important point here is to ensure that the port range used for FTP
|
2002-11-24 21:08:19 +01:00
|
|
|
|
passive connections is unique and will not overlap with any usage on
|
|
|
|
|
|
the firewall system.</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b>Example 5. </b>You
|
|
|
|
|
|
wish to allow unlimited
|
|
|
|
|
|
DMZ access to the host
|
|
|
|
|
|
with MAC address
|
|
|
|
|
|
02:00:08:E3:FA:55.</p>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote> <font
|
2002-11-09 19:06:34 +01:00
|
|
|
|
face="Century Gothic, Arial, Helvetica"> </font>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<tr>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<td><b>ACTION</b></td>
|
|
|
|
|
|
<td><b>SOURCE</b></td>
|
|
|
|
|
|
<td><b>DEST</b></td>
|
|
|
|
|
|
<td><b> PROTO</b></td>
|
|
|
|
|
|
<td><b>DEST<br>
|
|
|
|
|
|
PORT(S)</b></td>
|
|
|
|
|
|
<td><b>SOURCE<br>
|
|
|
|
|
|
PORT(S)</b></td>
|
|
|
|
|
|
<td><b>ORIGINAL<br>
|
|
|
|
|
|
DEST</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>ACCEPT</td>
|
|
|
|
|
|
<td>loc:~02-00-08-E3-FA-55</td>
|
|
|
|
|
|
<td>dmz</td>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
</tbody>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<b>Example 6.</b> You wish to
|
|
|
|
|
|
allow access to the SMTP server in your DMZ from all zones.<br>
|
|
|
|
|
|
<blockquote>
|
|
|
|
|
|
<table cellpadding="2" cellspacing="0" border="1">
|
|
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td valign="top"><b>ACTION</b><br>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td valign="top"><b>SOURCE<br>
|
|
|
|
|
|
</b></td>
|
|
|
|
|
|
<td valign="top"><b>DEST<br>
|
|
|
|
|
|
</b></td>
|
|
|
|
|
|
<td valign="top"><b>PROTO<br>
|
|
|
|
|
|
</b></td>
|
|
|
|
|
|
<td valign="top"><b>DEST<br>
|
|
|
|
|
|
PORTS(S)<br>
|
|
|
|
|
|
</b></td>
|
|
|
|
|
|
<td valign="top"><b>SOURCE<br>
|
|
|
|
|
|
PORT(S)<br>
|
|
|
|
|
|
</b></td>
|
|
|
|
|
|
<td valign="top"><b>ORIGINAL<br>
|
|
|
|
|
|
DEST<br>
|
|
|
|
|
|
</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td valign="top">ACCEPT<br>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td valign="top">all<br>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td valign="top">dmz<br>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td valign="top">tcp<br>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td valign="top">25<br>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td valign="top"><br>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td valign="top"><br>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
</tbody>
|
|
|
|
|
|
</table>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
Note: When 'all' is used as a source or destination, intra-zone traffic is
|
|
|
|
|
|
not affected. In this example, if there were two DMZ interfaces then the
|
|
|
|
|
|
above rule would NOT enable SMTP traffic between hosts on these interfaces.</blockquote>
|
|
|
|
|
|
<p><a href="ports.htm">Look here for information on other services.</a>
|
|
|
|
|
|
</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h2><a name="Common">
|
|
|
|
|
|
</a>/etc/shorewall/common</h2>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Shorewall allows
|
|
|
|
|
|
definition of rules that
|
|
|
|
|
|
apply between all zones.
|
|
|
|
|
|
By default, these rules
|
|
|
|
|
|
are defined in the file
|
|
|
|
|
|
/etc/shorewall/common.def
|
|
|
|
|
|
but may be modified to
|
|
|
|
|
|
suit individual
|
|
|
|
|
|
requirements. Rather
|
2002-11-24 21:08:19 +01:00
|
|
|
|
than modify
|
|
|
|
|
|
/etc/shorewall/common.def,
|
|
|
|
|
|
you should copy
|
|
|
|
|
|
that file to
|
|
|
|
|
|
/etc/shorewall/common
|
|
|
|
|
|
and modify that
|
|
|
|
|
|
file.</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>The /etc/shorewall/common
|
2002-11-24 21:08:19 +01:00
|
|
|
|
file is expected
|
|
|
|
|
|
to contain iptables
|
|
|
|
|
|
commands; rather
|
|
|
|
|
|
than running iptables
|
|
|
|
|
|
directly, you
|
|
|
|
|
|
should run it
|
|
|
|
|
|
indirectly using the
|
|
|
|
|
|
Shorewall function 'run_iptables'.
|
|
|
|
|
|
That way, if iptables
|
|
|
|
|
|
encounters an error, the
|
|
|
|
|
|
firewall will be safely
|
|
|
|
|
|
stopped.</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h2><a name="Masq"></a>
|
|
|
|
|
|
/etc/shorewall/masq</h2>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>The /etc/shorewall/masq file is used to define classical IP Masquerading
|
2002-11-24 21:08:19 +01:00
|
|
|
|
and Source Network Address Translation<6F> (SNAT). There is one entry in
|
|
|
|
|
|
the file for each subnet that you want to masquerade. In order to make
|
|
|
|
|
|
use of this feature, you must have <a href="#NatEnabled">NAT enabled</a>
|
|
|
|
|
|
.</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> Columns are:</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b> INTERFACE</b> - The interface that will masquerade the
|
|
|
|
|
|
subnet; this is normally your internet interface. This interface
|
|
|
|
|
|
name can be optionally qualified by adding ":" and a subnet or host
|
|
|
|
|
|
IP. When this qualification is added, only packets addressed to that
|
|
|
|
|
|
host or subnet will be masqueraded.</li>
|
|
|
|
|
|
<li><b> SUBNET</b> - The subnet that you want to have masqueraded
|
|
|
|
|
|
through the INTERFACE. This may be expressed as a single IP address,
|
|
|
|
|
|
a subnet or an interface name. In the latter instance, the interface
|
|
|
|
|
|
must be configured and started before Shorewall is started as Shorewall
|
|
|
|
|
|
will determine the subnet based on information obtained from the 'ip'
|
|
|
|
|
|
utility.<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
The subnet may be optionally followed by "!' and a comma-separated
|
|
|
|
|
|
list of addresses and/or subnets that are to be excluded from masquerading.</li>
|
|
|
|
|
|
<li><b>ADDRESS</b> - The source address to be used for outgoing
|
|
|
|
|
|
packets. This column is optional and if left blank, the current primary
|
|
|
|
|
|
IP address of the interface in the first column is used. If you have
|
|
|
|
|
|
a static IP on that interface, listing it here makes processing of output
|
|
|
|
|
|
packets a little less expensive for the firewall.</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b> Example 1: </b> You have eth0 connected to a cable modem and eth1
|
2002-11-24 21:08:19 +01:00
|
|
|
|
connected to your local subnetwork 192.168.9.0/24. Your /etc/shorewall/masq
|
|
|
|
|
|
file would look like:<3A><><EFBFBD><EFBFBD></p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b> INTERFACE</b></td>
|
|
|
|
|
|
<td><b> SUBNET</b></td>
|
|
|
|
|
|
<td><b>ADDRESS</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>eth0</td>
|
|
|
|
|
|
<td>192.168.9.0/24</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</tbody>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b> Example 2:</b> You have a number of IPSEC tunnels through ipsec0
|
2002-11-24 21:08:19 +01:00
|
|
|
|
and you want to masquerade traffic from your 192.168.9.0/24 subnet to
|
|
|
|
|
|
the remote subnet 10.1.0.0/16 only.</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b> INTERFACE</b></td>
|
|
|
|
|
|
<td><b> SUBNET</b></td>
|
|
|
|
|
|
<td><b>ADDRESS</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>ipsec0:10.1.0.0/16</td>
|
|
|
|
|
|
<td>192.168.9.0/24</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</tbody>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b> Example 3:</b> You have a DSL line connected on eth0 and a local
|
2002-11-24 21:08:19 +01:00
|
|
|
|
network (192.168.10.0/24)
|
|
|
|
|
|
connected to
|
|
|
|
|
|
eth1. You want
|
|
|
|
|
|
all local->net
|
|
|
|
|
|
connections to use
|
|
|
|
|
|
source address
|
|
|
|
|
|
206.124.146.176.</p>
|
|
|
|
|
|
|
|
|
|
|
|
<blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<tr>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<td><b> INTERFACE</b></td>
|
|
|
|
|
|
<td><b> SUBNET</b></td>
|
|
|
|
|
|
<td><b>ADDRESS</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>eth0</td>
|
|
|
|
|
|
<td>192.168.10.0/24</td>
|
|
|
|
|
|
<td>206.124.146.176</td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
</tbody>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b>Example 4: </b>
|
|
|
|
|
|
Same as example 3
|
|
|
|
|
|
except that you wish
|
|
|
|
|
|
to exclude
|
|
|
|
|
|
192.168.10.44 and
|
|
|
|
|
|
192.168.10.45 from
|
|
|
|
|
|
the SNAT rule.</p>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<tr>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<td><b> INTERFACE</b></td>
|
|
|
|
|
|
<td><b> SUBNET</b></td>
|
|
|
|
|
|
<td><b>ADDRESS</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>eth0</td>
|
|
|
|
|
|
<td>192.168.10.0/24!192.168.10.44,192.168.10.45</td>
|
|
|
|
|
|
<td>206.124.146.176</td>
|
|
|
|
|
|
</tr>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
</tbody>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h2><font color="#660066"><b><a name="ProxyArp"></a>
|
|
|
|
|
|
</b></font>/etc/shorewall/proxyarp</h2>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>If you want to
|
|
|
|
|
|
use proxy ARP on an
|
|
|
|
|
|
entire sub-network,
|
|
|
|
|
|
I suggest that you
|
|
|
|
|
|
look at
|
|
|
|
|
|
<a
|
|
|
|
|
|
href="http://www.tldp.org/HOWTO/mini/Proxy-ARP-Subnet/">
|
|
|
|
|
|
http://www.tldp.org/HOWTO/mini/Proxy-ARP-Subnet/</a>.
|
2002-11-24 21:08:19 +01:00
|
|
|
|
If you decide
|
|
|
|
|
|
to use the
|
|
|
|
|
|
technique described
|
|
|
|
|
|
in that HOWTO,
|
|
|
|
|
|
you can set
|
|
|
|
|
|
the proxy_arp flag
|
|
|
|
|
|
for an interface
|
|
|
|
|
|
(/proc/sys/net/ipv4/conf/<i><interface></i>/proxy_arp)
|
|
|
|
|
|
by including
|
|
|
|
|
|
the <b> proxyarp</b>
|
|
|
|
|
|
option in
|
|
|
|
|
|
the interface's
|
|
|
|
|
|
record in
|
|
|
|
|
|
<a href="#Interfaces">
|
|
|
|
|
|
/etc/shorewall/interfaces</a>.
|
|
|
|
|
|
When using Proxy ARP
|
|
|
|
|
|
sub-netting, you do
|
|
|
|
|
|
<u>NOT</u> include
|
|
|
|
|
|
any entries in
|
|
|
|
|
|
/etc/shorewall/proxyarp.
|
|
|
|
|
|
</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>The /etc/shorewall/proxyarp file is used to define <a
|
|
|
|
|
|
href="ProxyARP.htm">Proxy ARP</a>. The file is
|
|
|
|
|
|
typically used for
|
|
|
|
|
|
enabling Proxy ARP
|
|
|
|
|
|
on a small set of
|
|
|
|
|
|
systems since you
|
|
|
|
|
|
need one entry
|
2002-11-24 21:08:19 +01:00
|
|
|
|
in this file
|
|
|
|
|
|
for each system
|
|
|
|
|
|
using proxy
|
|
|
|
|
|
ARP. Columns are:</p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b> ADDRESS</b> - address of the system.</li>
|
|
|
|
|
|
<li><b> INTERFACE</b> - the interface that connects to the system.
|
|
|
|
|
|
If the interface is obvious from the subnetting, you may enter "-"
|
|
|
|
|
|
in this column.</li>
|
|
|
|
|
|
<li><b> EXTERNAL</b> - the external interface that you want
|
|
|
|
|
|
to honor ARP requests for the ADDRESS specified in the first column.</li>
|
|
|
|
|
|
<li><b>HAVEROUTE</b> - If
|
|
|
|
|
|
you already have
|
|
|
|
|
|
a route through
|
|
|
|
|
|
INTERFACE to
|
|
|
|
|
|
ADDRESS, this
|
|
|
|
|
|
column should
|
|
|
|
|
|
contain
|
|
|
|
|
|
"Yes"
|
|
|
|
|
|
or
|
|
|
|
|
|
"yes".
|
|
|
|
|
|
If you want
|
|
|
|
|
|
Shorewall to add
|
|
|
|
|
|
the route, the
|
|
|
|
|
|
column should
|
|
|
|
|
|
contain
|
|
|
|
|
|
"No"
|
|
|
|
|
|
or
|
|
|
|
|
|
"no".</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><font color="#cc6666"><b>Note: After you have made a change to the /etc/shorewall/proxyarp
|
2002-11-24 21:08:19 +01:00
|
|
|
|
file, you may need to flush the ARP cache of all routers on the LAN segment
|
|
|
|
|
|
connected to the interface specified in the EXTERNAL column of the change/added
|
|
|
|
|
|
entry(s). If you are having problems communicating between an individual
|
|
|
|
|
|
host (A) on that segment and a system whose entry has changed, you may
|
|
|
|
|
|
need to flush the ARP cache on host A as well.</b></font></p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><font color="#cc6666"><b>ISPs typically have ARP configured with long TTL
|
|
|
|
|
|
(hours!) so if your ISPs router has a stale cache entry (as seen using "tcpdump
|
|
|
|
|
|
-nei <external interface> host <IP addr>"), it may take a long
|
|
|
|
|
|
while to time out. I personally have had to contact my ISP and ask them
|
|
|
|
|
|
to delete a stale entry in order to restore a system to working order after
|
|
|
|
|
|
changing my proxy ARP settings. </b></font></p>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b>Example:
|
|
|
|
|
|
</b> You have public IP addresses 155.182.235.0/28. You configure your
|
2002-11-24 21:08:19 +01:00
|
|
|
|
firewall as follows:</p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li>eth0 - 155.186.235.1 (internet connection)</li>
|
|
|
|
|
|
<li>eth1 - 192.168.9.0/24 (masqueraded local systems)</li>
|
|
|
|
|
|
<li>eth2 - 192.168.10.1 (interface to your DMZ)</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> In your DMZ, you want to install a Web/FTP server with public address
|
2002-11-24 21:08:19 +01:00
|
|
|
|
155.186.235.4. On the Web server, you subnet just like the firewall's
|
|
|
|
|
|
eth0 and you configure 155.186.235.1 as the default gateway. In your
|
|
|
|
|
|
/etc/shorewall/proxyarp file, you will have:</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="2" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b> ADDRESS</b></td>
|
|
|
|
|
|
<td><b> INTERFACE</b></td>
|
|
|
|
|
|
<td><b> EXTERNAL</b></td>
|
|
|
|
|
|
<td><b>HAVEROUTE</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>155.186.235.4</td>
|
|
|
|
|
|
<td>eth2</td>
|
|
|
|
|
|
<td>eth0</td>
|
|
|
|
|
|
<td>No</td>
|
|
|
|
|
|
</tr>
|
2002-09-29 23:42:38 +02:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</tbody>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> Note: You may want to configure the servers in your DMZ with a subnet
|
2002-11-24 21:08:19 +01:00
|
|
|
|
that is smaller than the subnet of your internet interface. See the
|
|
|
|
|
|
Proxy ARP Subnet Mini HOWTO (<a
|
2002-09-16 19:13:10 +02:00
|
|
|
|
href="http://www.tldp.org/HOWTO/mini/Proxy-ARP-Subnet/">http://www.tldp.org/HOWTO/mini/Proxy-ARP-Subnet/</a>)
|
2002-11-24 21:08:19 +01:00
|
|
|
|
for details. In this case you will want to place "Yes" in the HAVEROUTE
|
|
|
|
|
|
column.</p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>To learn how I use Proxy ARP in my DMZ, see <a href="myfiles.htm">my configuration
|
|
|
|
|
|
files</a>.</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><font color="#ff6633"><b>Warning: </b></font>Do not use Proxy ARP and
|
|
|
|
|
|
FreeS/Wan on the same system unless you are prepared to suffer the consequences.
|
2002-11-24 21:08:19 +01:00
|
|
|
|
If you start or restart Shorewall with an IPSEC tunnel active, the proxied
|
|
|
|
|
|
IP addresses are mistakenly assigned to the IPSEC tunnel device (ipsecX)
|
|
|
|
|
|
rather than to the interface that you specify in the INTERFACE column
|
|
|
|
|
|
of /etc/shorewall/proxyarp. I haven't had the time to debug this problem
|
|
|
|
|
|
so I can't say if it is a bug in the Kernel or in FreeS/Wan.<2E></p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>You <b>might</b> be able to work around this problem using the following
|
2002-11-24 21:08:19 +01:00
|
|
|
|
(I haven't tried it):</p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>In /etc/shorewall/init, include:</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><EFBFBD><EFBFBD><EFBFBD><EFBFBD> qt service ipsec stop</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>In /etc/shorewall/start, include:</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><EFBFBD><EFBFBD><EFBFBD> qt service ipsec start</p>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h2><font color="#660066"><b><a name="NAT"></a>
|
|
|
|
|
|
</b></font>/etc/shorewall/nat</h2>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>The /etc/shorewall/nat file is used to define static NAT. There is one
|
2002-11-24 21:08:19 +01:00
|
|
|
|
entry in the file for each static NAT relationship that you wish to
|
|
|
|
|
|
define. In order to make use of this feature, you must have <a
|
2002-09-16 19:13:10 +02:00
|
|
|
|
href="#NatEnabled">NAT enabled</a> .</p>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> <font
|
|
|
|
|
|
color="#ff0000">
|
|
|
|
|
|
<b>IMPORTANT: If
|
|
|
|
|
|
all you want to do
|
|
|
|
|
|
is forward ports
|
|
|
|
|
|
to servers behind
|
|
|
|
|
|
your firewall, you
|
|
|
|
|
|
do NOT want to use
|
|
|
|
|
|
static NAT. Port
|
|
|
|
|
|
forwarding can
|
|
|
|
|
|
be accomplished
|
2002-11-24 21:08:19 +01:00
|
|
|
|
with simple
|
|
|
|
|
|
entries in
|
|
|
|
|
|
the <a
|
2002-09-16 19:13:10 +02:00
|
|
|
|
href="#Rules">
|
|
|
|
|
|
rules file</a>.
|
|
|
|
|
|
Also, in most
|
|
|
|
|
|
cases
|
|
|
|
|
|
<a href="#ProxyArp">
|
|
|
|
|
|
Proxy ARP</a>
|
|
|
|
|
|
provides a
|
|
|
|
|
|
superior solution
|
|
|
|
|
|
to static NAT
|
|
|
|
|
|
because the
|
|
|
|
|
|
internal systems
|
|
|
|
|
|
are accessed using
|
|
|
|
|
|
the same IP
|
|
|
|
|
|
address internally
|
2002-11-24 21:08:19 +01:00
|
|
|
|
and externally.</b></font></p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Columns in an entry are:</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b> EXTERNAL</b> - External IP address - <u>This should
|
|
|
|
|
|
NOT be the primary IP address of the interface named in the next column.</u></li>
|
|
|
|
|
|
<li><b> INTERFACE</b> - Interface that you want the EXTERNAL
|
|
|
|
|
|
IP address to appear on.</li>
|
|
|
|
|
|
<li><b> INTERNAL </b> - Internal IP address.</li>
|
|
|
|
|
|
<li><b>ALL
|
|
|
|
|
|
INTERFACES</b>
|
|
|
|
|
|
- If Yes
|
|
|
|
|
|
or yes (or
|
|
|
|
|
|
left
|
|
|
|
|
|
empty),
|
|
|
|
|
|
NAT will
|
|
|
|
|
|
be
|
|
|
|
|
|
effective
|
|
|
|
|
|
from all
|
|
|
|
|
|
hosts.
|
|
|
|
|
|
If
|
|
|
|
|
|
No or no
|
|
|
|
|
|
then NAT
|
|
|
|
|
|
will be
|
|
|
|
|
|
effective
|
|
|
|
|
|
only
|
|
|
|
|
|
through
|
|
|
|
|
|
the
|
|
|
|
|
|
interface
|
|
|
|
|
|
named in
|
|
|
|
|
|
the
|
|
|
|
|
|
INTERFACE
|
|
|
|
|
|
column. <b> Note:</b>
|
|
|
|
|
|
If two or more NATed systems are connected to the same firewall interface
|
|
|
|
|
|
and you want them to be able to communicate using their EXTERNAL IP
|
|
|
|
|
|
addresses, then you will want to specify the <b>multi</b> option in the
|
|
|
|
|
|
<a href="#Interfaces">/etc/shorewall/interface</a> entry for that interface.</li>
|
|
|
|
|
|
<li><b>LOCAL</b> - If Yes or yes and the ALL INTERFACES column
|
|
|
|
|
|
contains Yes or yes, NAT will be effective from the firewall system.
|
|
|
|
|
|
<b>Note: </b>For this to work, you must be running kernel 2.4.19
|
|
|
|
|
|
or later and iptables 1.2.6a or later and you must have enabled<65> <b>CONFIG_IP_NF_NAT_LOCAL</b>
|
|
|
|
|
|
in your kernel.</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b><a href="NAT.htm"> Look here for additional information and an example.</a>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</b></p>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h2><font color="#660066"><a name="Tunnels"></a>
|
|
|
|
|
|
</font>/etc/shorewall/tunnels</h2>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<p> The /etc/shorewall/tunnels file allows you to define IPSec, GRE, IPIP
|
2002-11-24 21:08:19 +01:00
|
|
|
|
and PPTP tunnels with end-points on your firewall. To use ipsec, you must
|
|
|
|
|
|
install version 1.9, 1.91 or the current <a
|
2002-09-16 19:13:10 +02:00
|
|
|
|
href="http://www.xs4all.nl/%7Efreeswan/">FreeS/WAN</a> development snapshot.<2E></p>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> Note: For kernels 2.4.4 and above, you will need to use version 1.91
|
2002-11-24 21:08:19 +01:00
|
|
|
|
or a development snapshot as patching with version 1.9 results in kernel
|
|
|
|
|
|
compilation errors.</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b><a href="IPSEC.htm"> Instructions for setting up IPSEC tunnels may
|
2002-11-24 21:08:19 +01:00
|
|
|
|
be found here,</a></b> <b><a href="IPIP.htm">instructions for IPIP and
|
|
|
|
|
|
GRE tunnels are here</a> <20></b>and <b><a href="PPTP.htm">instructions
|
|
|
|
|
|
for PPTP tunnels are here</a>.</b></p>
|
|
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<h2>/etc/shorewall/shorewall.conf</h2>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> This file is used to set the following firewall parameters:</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b>TCP_FLAGS_DISPOSITION - </b>Added in Version 1.3.11<br>
|
|
|
|
|
|
Determines the disposition of TCP packets that fail the checks enabled by
|
|
|
|
|
|
the <a href="#Interfaces%5C">tcpflags</a> interface option and must have
|
|
|
|
|
|
a value of ACCEPT (accept the packet), REJECT (send an RST response) or DROP
|
|
|
|
|
|
(ignore the packet). If not set or if set to the empty value (e.g., TCP_FLAGS_DISPOSITION="")
|
|
|
|
|
|
then TCP_FLAGS_DISPOSITION=DROP is assumed.</li>
|
|
|
|
|
|
<li><b>TCP_FLAGS_LOG_LEVEL - </b>Added in Version 1.3.11<br>
|
|
|
|
|
|
Determines the syslogd log level for logging packets that fail the checks
|
|
|
|
|
|
enabled by the <a href="#Interfaces">tcpflags</a> interface option.The value
|
|
|
|
|
|
must be a valid syslogd log level. If you don't want to log these packets,
|
|
|
|
|
|
set to the empty value (e.g., TCP_FLAGS_LOG_LEVEL="").<br>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li><b>MACLIST_DISPOSITION </b>- Added in Version 1.3.10<br>
|
|
|
|
|
|
Determines the disposition of connections requests that fail <a
|
2002-11-09 19:06:34 +01:00
|
|
|
|
href="MAC_Validation.html">MAC Verification</a> and must have the value ACCEPT
|
|
|
|
|
|
(accept the connection request anyway), REJECT (reject the connection request)
|
|
|
|
|
|
or DROP (ignore the connection request). If not set or if set to the empty
|
|
|
|
|
|
value (e.g., MACLIST_DISPOSITION="") then MACLIST_DISPOSITION=REJECT is assumed.</li>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b>MACLIST_LOG_LEVEL </b>- Added in Version 1.3.10<br>
|
|
|
|
|
|
Determines the syslogd log level for logging connection requests that
|
|
|
|
|
|
fail <a href="MAC_Validation.html">MAC Verification</a>. The value must
|
|
|
|
|
|
be a valid syslogd log level. If you don't want to log these connection
|
|
|
|
|
|
requests, set to the empty value (e.g., MACLIST_LOG_LEVEL="").<br>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li><b>NEWNOTSYN </b>- Added in Version 1.3.8<br>
|
|
|
|
|
|
When set to "Yes" or "yes", Shorewall will filter TCP packets that
|
|
|
|
|
|
are not part of an established connention and that are not SYN packets
|
|
|
|
|
|
(SYN flag on - ACK flag off). If set to "No", Shorewall will silently drop
|
|
|
|
|
|
such packets. If not set or set to the empty value (e.g., "NEWNOTSYN="),
|
|
|
|
|
|
NEWNOTSYN=No is assumed.<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
If you have a HA setup with failover to another firewall, you should
|
|
|
|
|
|
have NEWNOTSYN=Yes on both firewalls. You should also select NEWNOTSYN=Yes
|
|
|
|
|
|
if you have asymmetric routing.<br>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li><b>FORWARDPING</b> - Added in Version 1.3.7<br>
|
|
|
|
|
|
When set to "Yes" or "yes", ICMP echo-request (ping) packets from
|
|
|
|
|
|
interfaces that specify "filterping" are ACCEPTed by the firewall.
|
2002-11-09 19:06:34 +01:00
|
|
|
|
When set to "No" or "no", such ping requests are silently dropped unless
|
2002-11-24 21:08:19 +01:00
|
|
|
|
they are handled by an explicit entry in the <a href="#Rules">rules
|
2002-09-29 23:42:38 +02:00
|
|
|
|
file</a>. If not specified, "No" is assumed.</li>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b>LOGNEWNOTSYN</b> - Added in Version 1.3.6<br>
|
|
|
|
|
|
Beginning with version 1.3.6, Shorewall drops non-SYN TCP packets
|
|
|
|
|
|
that are not part of an existing connection. If you would like to
|
|
|
|
|
|
log these packets, set LOGNEWNOTSYN to the syslog level at which you
|
|
|
|
|
|
want the packets logged. Example: LOGNEWNOTSYN=debug|<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
<b>Note: </b>Packets logged under this option are usually the
|
|
|
|
|
|
result of broken remote IP stacks rather than the result of any sort
|
|
|
|
|
|
of attempt to breach your firewall.<br>
|
|
|
|
|
|
<20></li>
|
|
|
|
|
|
<li><b>MERGE_HOSTS </b>- Added in Version 1.3.5<br>
|
|
|
|
|
|
Prior to 1.3.5, when the <a href="#Hosts">/etc/shorewall/hosts</a>
|
|
|
|
|
|
file included an entry for a zone then the entire zone had to be defined
|
|
|
|
|
|
in the /etc/shorewall/hosts file and any associations between the zone
|
|
|
|
|
|
and interfaces in the <a href="#Interfaces">/etc/shorewall/interfaces</a>
|
|
|
|
|
|
file were ignored. This behavior is preserved if MERGE_HOSTS=No or
|
|
|
|
|
|
if MERGE_HOSTS is not set or is set to the empty value.<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
Beginning with version 1.3.5, if MERGE_HOSTS=Yes, then zone assignments
|
|
|
|
|
|
in the /etc/shorewall/hosts file are ADDED to those in the /etc/shorewall/interfaces
|
|
|
|
|
|
file. <br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
Example:<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
Interfaces File:<br>
|
|
|
|
|
|
<20>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;"
|
|
|
|
|
|
id="AutoNumber2">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><u><b>ZONE</b></u></td>
|
|
|
|
|
|
<td><u><b>HOSTS</b></u></td>
|
|
|
|
|
|
<td><u><b>BROADCAST</b></u></td>
|
|
|
|
|
|
<td><u><b>OPTIONS</b></u></td>
|
|
|
|
|
|
</tr>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<tr>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<td>loc</td>
|
|
|
|
|
|
<td>eth1</td>
|
|
|
|
|
|
<td>-</td>
|
|
|
|
|
|
<td>dhcp</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>-</td>
|
|
|
|
|
|
<td>ppp+</td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
<td><EFBFBD></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
|
|
|
|
|
|
</tbody>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><br>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
Hosts File:<br>
|
|
|
|
|
|
<20></p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="1" cellpadding="2" style="border-collapse: collapse;"
|
|
|
|
|
|
id="AutoNumber3">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><u><b>ZONE</b></u></td>
|
|
|
|
|
|
<td><u><b>HOSTS</b></u></td>
|
|
|
|
|
|
</tr>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<tr>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<td>loc</td>
|
|
|
|
|
|
<td>ppp+:192.168.12.0/24</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
|
|
|
|
|
|
</tbody>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><font face="Courier"><br>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</font>With MERGE_HOSTS=No, the<b> loc</b> zone consists of only
|
|
|
|
|
|
ppp+:192.168.12.0/24; with MERGE_HOSTS=Yes, it includes eth1:0.0.0.0/0
|
|
|
|
|
|
and ppp+:192.168.12.0/24.<br>
|
|
|
|
|
|
<20> </p>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li><b>DETECT_DNAT_ADDRS</b> - Added in Version 1.3.4<br>
|
|
|
|
|
|
If set to "Yes" or "yes", Shorewall will detect the IP address(es)
|
|
|
|
|
|
of the interface(es) to the source zone and will include this (these) address(es)
|
|
|
|
|
|
in DNAT rules as the original destination IP address. If set to "No" or
|
|
|
|
|
|
"no", Shorewall will not detect this (these) address(es) and any destination
|
|
|
|
|
|
IP address will match the DNAT rule. If not specified or empty, "DETECT_DNAT_ADDRS=Yes"
|
|
|
|
|
|
is assumed.<br>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li><b>MULTIPORT</b> - Added in Version 1.3.2<br>
|
|
|
|
|
|
If set to "Yes" or "yes", Shorewall will use the Netfilter multiport
|
|
|
|
|
|
facility. In order to use this facility, your kernel must have multiport
|
|
|
|
|
|
support (CONFIG_IP_NF_MATCH_MULTIPORT). When this support is used,
|
|
|
|
|
|
Shorewall will generate a single rule from each record in the /etc/shorewall/rules
|
|
|
|
|
|
file that meets these criteria:<br>
|
|
|
|
|
|
<20>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li>No port range(s) specified</li>
|
|
|
|
|
|
<li>Specifies 15 or fewer ports</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Rules not meeting those criteria will continue to generate an individual
|
2002-11-24 21:08:19 +01:00
|
|
|
|
rule for each listed port or port range. </p>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li><b>NAT_BEFORE_RULES</b><br>
|
|
|
|
|
|
If set to "No" or "no", port forwarding rules can override the
|
|
|
|
|
|
contents of the <a href="#NAT">/etc/shorewall/nat</a> file. If set
|
|
|
|
|
|
to "Yes" or "yes", port forwarding rules cannot override static NAT.
|
|
|
|
|
|
If not set or set to an empty value, "Yes" is assumed.</li>
|
|
|
|
|
|
<li><b>FW<br>
|
|
|
|
|
|
|
|
|
|
|
|
</b>This
|
|
|
|
|
|
parameter
|
|
|
|
|
|
specifies the
|
|
|
|
|
|
name of the
|
|
|
|
|
|
firewall zone.
|
|
|
|
|
|
If not set or
|
|
|
|
|
|
if set to an
|
|
|
|
|
|
empty string,
|
|
|
|
|
|
the value
|
|
|
|
|
|
"fw"
|
|
|
|
|
|
is assumed.</li>
|
|
|
|
|
|
<li><b>SUBSYSLOCK</b><br>
|
|
|
|
|
|
This parameter should be set to the name of a file that
|
|
|
|
|
|
the firewall should create if it starts successfully and remove
|
|
|
|
|
|
when it stops. Creating and removing this file allows Shorewall
|
|
|
|
|
|
to work with your distribution's initscripts. For RedHat, this
|
|
|
|
|
|
should be set to /var/lock/subsys/shorewall. For Debian, the value
|
|
|
|
|
|
is /var/state/shorewall and in LEAF it is
|
|
|
|
|
|
/var/run/shorwall.
|
|
|
|
|
|
Example: SUBSYSLOCK=/var/lock/subsys/shorewall.</li>
|
|
|
|
|
|
<li><b> STATEDIR</b><br>
|
|
|
|
|
|
This parameter specifies the name of a directory where Shorewall
|
|
|
|
|
|
stores state information. If the directory doesn't exist when Shorewall
|
|
|
|
|
|
starts, it will create the directory. Example: STATEDIR=/tmp/shorewall.<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
<b>NOTE:</b> If you change the STATEDIR variable while the firewall
|
|
|
|
|
|
is running, create the new directory if necessary then copy the contents
|
|
|
|
|
|
of the old directory to the new directory. </li>
|
|
|
|
|
|
<li><b> ALLOWRELATED</b><br>
|
|
|
|
|
|
This parameter must be assigned the value "Yes" ("yes")
|
|
|
|
|
|
or "No" ("no") and specifies whether Shorewall allows connection
|
|
|
|
|
|
requests that are related to an already allowed connection. If you
|
|
|
|
|
|
say "No" ("no"), you can still override this setting by including
|
2002-09-29 23:42:38 +02:00
|
|
|
|
"related" rules in /etc/shorewall/rules ("related" given as the protocol).
|
|
|
|
|
|
If you specify ALLOWRELATED=No, you will need to include rules in
|
|
|
|
|
|
<a href="shorewall_extension_scripts.htm">/etc/shorewall/icmpdef</a>
|
|
|
|
|
|
to handle common ICMP packet types.</li>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b> MODULESDIR</b><br>
|
|
|
|
|
|
This parameter specifies the directory where your kernel
|
|
|
|
|
|
netfilter modules may be found. If you leave the variable empty,
|
|
|
|
|
|
Shorewall will supply the value "/lib/modules/`uname -r`/kernel/net/ipv4/netfilter.</li>
|
|
|
|
|
|
<li><b> LOGRATE </b> and <b> LOGBURST</b><br>
|
|
|
|
|
|
These parameters set the match rate and initial burst size
|
|
|
|
|
|
for logged packets. Please see the iptables man page for a description
|
|
|
|
|
|
of the behavior of these parameters (the iptables option --limit is
|
|
|
|
|
|
set by LOGRATE and --limit-burst is set by LOGBURST). If both parameters
|
|
|
|
|
|
are set empty, no rate-limiting will occur.<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
Example:<br>
|
|
|
|
|
|
<20><><EFBFBD> LOGRATE=10/minute<br>
|
|
|
|
|
|
<20><><EFBFBD> LOGBURST=5<br>
|
|
|
|
|
|
<20></li>
|
|
|
|
|
|
<li><b>LOGFILE</b><br>
|
|
|
|
|
|
|
|
|
|
|
|
This parameter
|
|
|
|
|
|
tells the
|
|
|
|
|
|
/sbin/shorewall
|
|
|
|
|
|
program where
|
|
|
|
|
|
to look for
|
|
|
|
|
|
Shorewall
|
|
|
|
|
|
messages when
|
|
|
|
|
|
processing the
|
|
|
|
|
|
"show
|
|
|
|
|
|
log",
|
|
|
|
|
|
"monitor",
|
|
|
|
|
|
"status"
|
|
|
|
|
|
and
|
|
|
|
|
|
"hits"
|
|
|
|
|
|
commands. If
|
|
|
|
|
|
not assigned
|
|
|
|
|
|
or if assigned
|
|
|
|
|
|
an empty
|
|
|
|
|
|
value,
|
|
|
|
|
|
/var/log/messages
|
|
|
|
|
|
is assumed.</li>
|
|
|
|
|
|
<li><b>NAT_ENABLED</b><br>
|
|
|
|
|
|
This parameter determines whether Shorewall supports NAT
|
|
|
|
|
|
operations.<2E>NAT operations include:<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
<20><><EFBFBD> Static NAT<br>
|
|
|
|
|
|
<20><><EFBFBD> Port Forwarding<br>
|
|
|
|
|
|
<20><><EFBFBD> Port Redirection<br>
|
|
|
|
|
|
<20><><EFBFBD> Masquerading<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
If the parameter has no value or has a value of "Yes" or
|
|
|
|
|
|
"yes" then NAT is enabled. If the parameter has a value of "no"
|
|
|
|
|
|
or "No" then NAT is disabled.<br>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li><b> MANGLE_ENABLED</b><br>
|
|
|
|
|
|
This parameter determines if packet mangling is enabled.
|
|
|
|
|
|
If the parameter has no value or has a value of "Yes" or "yes" than
|
2002-11-09 19:06:34 +01:00
|
|
|
|
packet mangling is enabled. If the parameter has a value of "no"
|
|
|
|
|
|
or "No" then packet mangling is disabled. If packet mangling is
|
|
|
|
|
|
disabled, the /etc/shorewall/tos file is ignored.<br>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</li>
|
|
|
|
|
|
<li><b> IP_FORWARDING</b><br>
|
|
|
|
|
|
This parameter determines whether Shorewall enables or disables
|
|
|
|
|
|
IPV4 Packet Forwarding (/proc/sys/net/ipv4/ip_forward). Possible
|
|
|
|
|
|
values are:<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
<20><><EFBFBD> On or on - packet forwarding will be enabled.<br>
|
|
|
|
|
|
<20><><EFBFBD> Off or off - packet forwarding will be disabled.<br>
|
|
|
|
|
|
<20><><EFBFBD> Keep or keep - Shorewall will neither enable nor
|
|
|
|
|
|
disable packet forwarding.<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
If this variable is not set or is given an empty value (IP_FORWARD="")
|
|
|
|
|
|
then IP_FORWARD=On is assumed.<br>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li><b>ADD_IP_ALIASES</b><br>
|
|
|
|
|
|
This parameter determines whether Shorewall automatically
|
|
|
|
|
|
adds the
|
|
|
|
|
|
<i>external </i>address(es) in <a href="#NAT">/etc/shorewall/nat</a>
|
|
|
|
|
|
. If the variable is set to "Yes" or "yes" then Shorewall automatically
|
|
|
|
|
|
adds these aliases. If it is set to "No" or "no", you must
|
|
|
|
|
|
add these aliases yourself using your distribution's network configuration
|
|
|
|
|
|
tools.<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
If this variable is not set or is given an empty value (ADD_IP_ALIASES="")
|
|
|
|
|
|
then ADD_IP_ALIASES=Yes is assumed.</li>
|
|
|
|
|
|
<li><b>ADD_SNAT_ALIASES</b><br>
|
|
|
|
|
|
This parameter determines whether Shorewall automatically adds
|
|
|
|
|
|
the SNAT <i> ADDRESS </i>in <a href="#Masq">/etc/shorewall/masq</a>.
|
|
|
|
|
|
If the variable is set to "Yes" or "yes" then Shorewall automatically
|
|
|
|
|
|
adds these addresses. If it is set to "No" or "no", you must add these
|
|
|
|
|
|
addresses yourself using your distribution's network configuration tools.<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
If this variable is not set or is given an empty value (ADD_SNAT_ALIASES="")
|
|
|
|
|
|
then ADD_SNAT_ALIASES=No is assumed.<br>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li><b>LOGUNCLEAN</b><br>
|
|
|
|
|
|
|
|
|
|
|
|
This parameter
|
|
|
|
|
|
determines the
|
|
|
|
|
|
logging level
|
|
|
|
|
|
of
|
|
|
|
|
|
mangled/invalid
|
|
|
|
|
|
packets
|
|
|
|
|
|
controlled by
|
|
|
|
|
|
the '<a href="#Unclean">dropunclean
|
|
|
|
|
|
and logunclean</a>'
|
|
|
|
|
|
interface
|
|
|
|
|
|
options.
|
|
|
|
|
|
If LOGUNCLEAN
|
|
|
|
|
|
is empty
|
|
|
|
|
|
(LOGUNCLEAN=)
|
|
|
|
|
|
then
|
2002-11-09 19:06:34 +01:00
|
|
|
|
packets
|
|
|
|
|
|
selected by
|
|
|
|
|
|
'dropclean' are
|
|
|
|
|
|
dropped
|
|
|
|
|
|
silently
|
|
|
|
|
|
('logunclean'
|
|
|
|
|
|
packets are
|
|
|
|
|
|
logged under
|
|
|
|
|
|
the 'info' log
|
|
|
|
|
|
level).
|
|
|
|
|
|
Otherwise,
|
|
|
|
|
|
these packets
|
|
|
|
|
|
are logged
|
|
|
|
|
|
at the
|
|
|
|
|
|
specified
|
|
|
|
|
|
level
|
|
|
|
|
|
(Example:
|
|
|
|
|
|
LOGUNCLEAN=debug).</li>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b>BLACKLIST_DISPOSITION</b><br>
|
|
|
|
|
|
|
|
|
|
|
|
This parameter
|
|
|
|
|
|
determines the
|
|
|
|
|
|
disposition of
|
|
|
|
|
|
packets from
|
|
|
|
|
|
blacklisted
|
|
|
|
|
|
hosts. It may
|
|
|
|
|
|
have the value
|
|
|
|
|
|
DROP if the
|
|
|
|
|
|
packets are to
|
|
|
|
|
|
be dropped
|
|
|
|
|
|
or REJECT
|
|
|
|
|
|
if the
|
|
|
|
|
|
packets are to
|
|
|
|
|
|
be replied
|
|
|
|
|
|
with an ICMP
|
|
|
|
|
|
port
|
|
|
|
|
|
unreachable
|
|
|
|
|
|
reply or a TCP
|
|
|
|
|
|
RST (tcp
|
|
|
|
|
|
only). If you
|
|
|
|
|
|
do not assign
|
|
|
|
|
|
a value or if
|
|
|
|
|
|
you assign an
|
|
|
|
|
|
empty value
|
|
|
|
|
|
then DROP
|
2002-09-16 19:13:10 +02:00
|
|
|
|
is assumed.</li>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b>BLACKLIST_LOGLEVEL</b><br>
|
|
|
|
|
|
|
|
|
|
|
|
This paremter
|
|
|
|
|
|
determines if
|
|
|
|
|
|
packets from
|
2002-11-09 19:06:34 +01:00
|
|
|
|
blacklisted
|
2002-11-24 21:08:19 +01:00
|
|
|
|
hosts are
|
|
|
|
|
|
logged and it
|
|
|
|
|
|
determines the
|
|
|
|
|
|
syslog level
|
|
|
|
|
|
that they are
|
|
|
|
|
|
to be logged
|
|
|
|
|
|
at. Its
|
|
|
|
|
|
value is
|
|
|
|
|
|
a syslog
|
|
|
|
|
|
log level
|
|
|
|
|
|
(Example:
|
|
|
|
|
|
BLACKLIST_LOGLEVEL=debug).
|
|
|
|
|
|
If you do not
|
|
|
|
|
|
assign a value
|
|
|
|
|
|
or if you
|
|
|
|
|
|
assign an
|
|
|
|
|
|
empty value
|
|
|
|
|
|
then packets
|
|
|
|
|
|
from
|
|
|
|
|
|
blacklisted
|
|
|
|
|
|
hosts are
|
|
|
|
|
|
not logged.</li>
|
|
|
|
|
|
<li><b>CLAMPMSS</b><br>
|
|
|
|
|
|
|
|
|
|
|
|
This parameter
|
|
|
|
|
|
enables the
|
|
|
|
|
|
TCP Clamp MSS
|
|
|
|
|
|
to PMTU
|
|
|
|
|
|
feature of
|
|
|
|
|
|
Netfilter and
|
|
|
|
|
|
is usually
|
|
|
|
|
|
required when
|
|
|
|
|
|
your internet
|
|
|
|
|
|
connection is
|
|
|
|
|
|
through PPPoE
|
|
|
|
|
|
or PPTP.
|
|
|
|
|
|
If set to
|
2002-09-29 23:42:38 +02:00
|
|
|
|
"Yes"
|
|
|
|
|
|
or
|
|
|
|
|
|
"yes",
|
|
|
|
|
|
the feature
|
2002-11-24 21:08:19 +01:00
|
|
|
|
is enabled.
|
|
|
|
|
|
If left
|
|
|
|
|
|
blank or
|
|
|
|
|
|
set to
|
|
|
|
|
|
"No"
|
|
|
|
|
|
or
|
|
|
|
|
|
"no",
|
|
|
|
|
|
the feature is
|
|
|
|
|
|
not enabled.
|
|
|
|
|
|
Note: This
|
|
|
|
|
|
option
|
|
|
|
|
|
requires
|
|
|
|
|
|
CONFIG_IP_NF_TARGET_TCPMSS
|
|
|
|
|
|
<a href="kernel.htm">in
|
|
|
|
|
|
your kernel</a>.</li>
|
|
|
|
|
|
<li><b>ROUTE_FILTER</b><br>
|
|
|
|
|
|
If this parameter is given the value "Yes" or "yes" then route
|
|
|
|
|
|
filtering (anti-spoofing) is enabled on all network interfaces.
|
|
|
|
|
|
The default value is "no".</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h2><a name="modules"></a>
|
|
|
|
|
|
/etc/shorewall/modules Configuration</h2>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>The file /etc/shorewall/modules contains commands for loading the kernel
|
2002-11-24 21:08:19 +01:00
|
|
|
|
modules required by Shorewall-defined firewall rules. Shorewall will
|
|
|
|
|
|
source this file during start/restart provided that it exists and that
|
|
|
|
|
|
the directory specified by the MODULESDIR parameter exists (see <a
|
2002-11-09 19:06:34 +01:00
|
|
|
|
href="#Conf">/etc/shorewall/shorewall.conf</a> above).</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>The file that is released with Shorewall calls the Shorewall function
|
2002-11-24 21:08:19 +01:00
|
|
|
|
"loadmodule" for the set of modules that I load.</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>The <i>loadmodule</i> function is called as follows:</p>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote>
|
|
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>loadmodule
|
|
|
|
|
|
<i><modulename>
|
|
|
|
|
|
</i>[ <i> <module parameters> </i>]</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>where</p>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><i><modulename><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD></i></p>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-09-29 23:42:38 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>is the name of the modules without the trailing ".o" (example
|
|
|
|
|
|
ip_conntrack).</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><i> <module parameters></i></p>
|
|
|
|
|
|
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> Optional parameters to the insmod utility.</p>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
</blockquote>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> The function determines if the module named by <i><modulename>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</i> is already loaded and if not then the function determines if the
|
|
|
|
|
|
".o" file corresponding to the module exists in the <i>moduledirectory</i>;
|
|
|
|
|
|
if so, then the following command is executed:</p>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> insmod <i>moduledirectory</i>/<i><modulename></i>.o <i><module
|
2002-11-24 21:08:19 +01:00
|
|
|
|
parameters></i></p>
|
|
|
|
|
|
</blockquote>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> If the file doesn't exist, the function determines of the ".o.gz"
|
|
|
|
|
|
file corresponding to the module exists in the <i>moduledirectory</i>. If
|
|
|
|
|
|
it does, the function assumes that the running configuration supports compressed
|
|
|
|
|
|
modules and execute the following command:</p>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> insmod <i>moduledirectory/<modulename>.</i>o.gz <<i>module
|
2002-11-24 21:08:19 +01:00
|
|
|
|
parameters></i></p>
|
|
|
|
|
|
</blockquote>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h2><a name="TOS"></a>
|
|
|
|
|
|
/etc/shorewall/tos Configuration</h2>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> The /etc/shorewall/tos file allows you to set the Type of Service field
|
2002-11-24 21:08:19 +01:00
|
|
|
|
in packet headers based on packet source, packet destination, protocol,
|
|
|
|
|
|
source port and destination port.<2E>In order for this file to be processed
|
|
|
|
|
|
by Shorewall, you must have <a href="#MangleEnabled">mangle support
|
|
|
|
|
|
enabled</a> .</p>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> Entries in the file have the following columns:</p>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b> SOURCE</b> -- The source zone. May be qualified by following
|
|
|
|
|
|
the zone name with a colon (":") and either an IP address, an IP
|
|
|
|
|
|
subnet, a MAC address in <a href="#MAC">Shorewall Format</a> or the
|
|
|
|
|
|
name of an interface. This column may also contain the <a
|
|
|
|
|
|
href="#FW">name of
|
|
|
|
|
|
the firewall</a>
|
|
|
|
|
|
zone to indicate packets originating on the
|
|
|
|
|
|
firewall itself or "all" to indicate any source.</li>
|
|
|
|
|
|
<li><b> DEST</b> -- The destination zone. May be qualified by
|
|
|
|
|
|
following the zone name with a colon (":") and either an IP address
|
|
|
|
|
|
or an IP subnet. Because packets are marked prior to routing, you
|
|
|
|
|
|
may not specify the name of an interface. This column may also
|
|
|
|
|
|
contain<EFBFBD> "all" to indicate any destination.</li>
|
|
|
|
|
|
<li><b> PROTOCOL</b> -- The name of a protocol in /etc/protocols
|
|
|
|
|
|
or the protocol's number.</li>
|
|
|
|
|
|
<li><b> SOURCE PORT(S)</b> -- The source port or a port range.
|
|
|
|
|
|
For all ports, place a hyphen ("-") in this column.</li>
|
|
|
|
|
|
<li><b> DEST PORT(S)</b><EFBFBD> -- The destination port or a port
|
|
|
|
|
|
range. To indicate all ports, place a hyphen ("-") in this column.</li>
|
|
|
|
|
|
<li><b> TOS</b> -- The type of service. Must be one of the following:</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote>
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> Minimize-Delay (16)<br>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
Maximize-Throughput (8)<br>
|
|
|
|
|
|
Maximize-Reliability (4)<br>
|
|
|
|
|
|
Minimize-Cost (2)<br>
|
|
|
|
|
|
Normal-Service (0)</p>
|
|
|
|
|
|
</blockquote>
|
|
|
|
|
|
</blockquote>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p> The /etc/shorewall/tos file that is included with Shorewall contains
|
2002-11-24 21:08:19 +01:00
|
|
|
|
the following entries.</p>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
<blockquote>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="2" cellpadding="2" style="border-collapse: collapse;">
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td><b>SOURCE</b></td>
|
|
|
|
|
|
<td><b>DEST</b></td>
|
|
|
|
|
|
<td><b>PROTOCOL</b></td>
|
|
|
|
|
|
<td><b>SOURCE<br>
|
|
|
|
|
|
PORT(S)</b></td>
|
|
|
|
|
|
<td><b>DEST PORT(S)</b></td>
|
|
|
|
|
|
<td><b>TOS</b></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>tcp</td>
|
|
|
|
|
|
<td>-</td>
|
|
|
|
|
|
<td>ssh</td>
|
|
|
|
|
|
<td>16</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>tcp</td>
|
|
|
|
|
|
<td>ssh</td>
|
|
|
|
|
|
<td>-</td>
|
|
|
|
|
|
<td>16</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>tcp</td>
|
|
|
|
|
|
<td>-</td>
|
|
|
|
|
|
<td>ftp</td>
|
|
|
|
|
|
<td>16</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>tcp</td>
|
|
|
|
|
|
<td>ftp</td>
|
|
|
|
|
|
<td>-</td>
|
|
|
|
|
|
<td>16</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>tcp</td>
|
|
|
|
|
|
<td>-</td>
|
|
|
|
|
|
<td>ftp-data</td>
|
|
|
|
|
|
<td>8</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>all</td>
|
|
|
|
|
|
<td>tcp</td>
|
|
|
|
|
|
<td>ftp-data</td>
|
|
|
|
|
|
<td>-</td>
|
|
|
|
|
|
<td>8</td>
|
|
|
|
|
|
</tr>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</tbody>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><b>WARNING: </b>Users have reported that odd routing problems result from
|
2002-11-24 21:08:19 +01:00
|
|
|
|
adding the ESP and AH protocols to the /etc/shorewall/tos file. </p>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h2><a name="Blacklist"></a>/etc/shorewall/blacklist</h2>
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Each
|
|
|
|
|
|
line
|
|
|
|
|
|
in
|
|
|
|
|
|
/etc/shorewall/blacklist
|
|
|
|
|
|
contains
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
an
|
|
|
|
|
|
IP
|
|
|
|
|
|
address, a MAC address in <a href="#MAC">Shorewall
|
|
|
|
|
|
Format</a>
|
|
|
|
|
|
or
|
|
|
|
|
|
subnet
|
|
|
|
|
|
address.
|
|
|
|
|
|
Example:</p>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<pre> 130.252.100.69<br> 206.124.146.0/24</pre>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Packets
|
|
|
|
|
|
<u><b>from</b></u>
|
|
|
|
|
|
hosts
|
|
|
|
|
|
listed
|
|
|
|
|
|
in
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
the
|
|
|
|
|
|
blacklist
|
|
|
|
|
|
file
|
|
|
|
|
|
will
|
|
|
|
|
|
be
|
|
|
|
|
|
|
|
|
|
|
|
disposed
|
|
|
|
|
|
of
|
|
|
|
|
|
according
|
|
|
|
|
|
to
|
|
|
|
|
|
the
|
|
|
|
|
|
value
|
|
|
|
|
|
|
|
|
|
|
|
assigned
|
|
|
|
|
|
to
|
|
|
|
|
|
the <a href="#Conf">BLACKLIST_DISPOSITION</a>
|
|
|
|
|
|
|
|
|
|
|
|
and <a href="#Conf">BLACKLIST_LOGLEVEL </a>variables
|
|
|
|
|
|
in
|
|
|
|
|
|
|
|
|
|
|
|
/etc/shorewall/shorewall.conf.
|
|
|
|
|
|
Only
|
|
|
|
|
|
packets
|
|
|
|
|
|
|
|
|
|
|
|
arriving
|
|
|
|
|
|
on
|
|
|
|
|
|
interfaces
|
|
|
|
|
|
that
|
|
|
|
|
|
have
|
|
|
|
|
|
the
|
|
|
|
|
|
|
|
|
|
|
|
'<a href="#Interfaces">blacklist</a>'
|
|
|
|
|
|
option
|
|
|
|
|
|
in
|
|
|
|
|
|
|
|
|
|
|
|
/etc/shorewall/interfaces
|
|
|
|
|
|
are
|
|
|
|
|
|
checked
|
|
|
|
|
|
against
|
|
|
|
|
|
|
|
|
|
|
|
the
|
|
|
|
|
|
blacklist. The black list is designed to prevent listed
|
|
|
|
|
|
hosts/subnets from accessing services on <u><b>your</b></u> network.<br>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Beginning with Shorewall 1.3.8, the blacklist file has three columns:<br>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</p>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b>ADDRESS/SUBNET - </b>As described above.</li>
|
|
|
|
|
|
<li><b>PROTOCOL</b> - Optional. If specified, only packets specifying
|
|
|
|
|
|
this protocol will be blocked.</li>
|
|
|
|
|
|
<li><b>PORTS - </b>Optional; may only be given if PROTOCOL is tcp,
|
|
|
|
|
|
udp or icmp. Expressed as a comma-separated list of port numbers or service
|
|
|
|
|
|
names (from /etc/services). If present, only packets destined for the specified
|
|
|
|
|
|
protocol and one of the listed ports are blocked. When the PROTOCOL is
|
2002-11-09 19:06:34 +01:00
|
|
|
|
icmp, the PORTS column contains a comma-separated list of ICMP type numbers
|
|
|
|
|
|
or names (see "iptables -h icmp").<br>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Shorewall also has a <a href="blacklisting_support.htm">dynamic blacklist
|
2002-11-24 21:08:19 +01:00
|
|
|
|
capability.</a></p>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><font color="#cc6666"><b>IMPORTANT: The Shorewall blacklist file is <u>NOT</u>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
designed to police your users' web browsing -- to do that, I suggest that
|
|
|
|
|
|
you install and configure Squid (<a href="http://www.squid-cache.org">http://www.squid-cache.org</a>).
|
|
|
|
|
|
</b></font></p>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<h2><a name="rfc1918"></a>/etc/shorewall/rfc1918 (Added in Version 1.3.1)</h2>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>This file lists the subnets affected by the <a href="#Interfaces"><i>norfc1918</i>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
interface option</a>. Columns in the file are:</p>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b>SUBNET</b> - The subnet using VLSM notation (e.g.,
|
|
|
|
|
|
192.168.0.0/16).</li>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b>TARGET<i> </i></b>- What to do with packets to/from
|
|
|
|
|
|
the SUBNET:
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b>RETURN</b> - Process the packet normally thru the
|
|
|
|
|
|
rules and policies.</li>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b>DROP</b> - Silently drop the packet.</li>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b>logdrop</b> - Log then drop the packet.</li>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<h2><a name="Routestopped"></a>/etc/shorewall/routestopped (Added in Version
|
2002-11-24 21:08:19 +01:00
|
|
|
|
1.3.4)</h2>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<p>This file defines the hosts that are accessible from the firewall when
|
2002-11-24 21:08:19 +01:00
|
|
|
|
the firewall is stopped.<2E> Columns in the file are:</p>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<ul>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b>INTERFACE </b>- The firewall interface through which
|
|
|
|
|
|
the host(s) comminicate with the firewall.</li>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<li><b>HOST(S) </b>- (Optional) - A comma-separated list
|
|
|
|
|
|
of IP/Subnet addresses. If not supplied or supplied as "-" then 0.0.0.0/0
|
|
|
|
|
|
is assumed.</li>
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</ul>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p>Example: When your firewall is stopped, you want firewall accessibility
|
2002-11-24 21:08:19 +01:00
|
|
|
|
from local hosts 192.168.1.0/24 and from your DMZ. Your DMZ interfaces
|
|
|
|
|
|
through eth1 and your local hosts through eth2.</p>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<blockquote>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<table border="2" style="border-collapse: collapse;" id="AutoNumber1"
|
|
|
|
|
|
cellpadding="2">
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tbody>
|
|
|
|
|
|
<tr>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<td><u><b>INTERFACE</b></u></td>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<td><u><b>HOST(S)</b></u></td>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</tr>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tr>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<td>eth2</td>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<td>192.168.1.0/24</td>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</tr>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<tr>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<td>eth1</td>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<td>-</td>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</tr>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
|
|
|
|
|
</tbody>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</table>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
</blockquote>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<h2><a name="Maclist"></a>/etc/shorewall/maclist (Added in Version 1.3.10)</h2>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
This file is described in the <a href="MAC_Validation.html">MAC Validation
|
|
|
|
|
|
Documentation</a>.<br>
|
|
|
|
|
|
<br>
|
|
|
|
|
|
|
|
|
|
|
|
<p><font size="2"> Updated 11/24/2002 - <a href="support.htm">Tom Eastep</a>
|
|
|
|
|
|
</font></p>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<p><font face="Trebuchet MS"><a href="copyright.htm"><font size="2">Copyright</font>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<20> <font size="2">2001, 2002 Thomas M. Eastep.</font></a></font></p>
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<font
|
2002-09-16 19:13:10 +02:00
|
|
|
|
face="Century Gothic, Arial, Helvetica">
|
2002-08-13 22:45:21 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2002-09-16 19:13:10 +02:00
|
|
|
|
</font><br>
|
2002-11-24 21:08:19 +01:00
|
|
|
|
<br>
|
|
|
|
|
|
<br>
|
2002-11-09 19:06:34 +01:00
|
|
|
|
<br>
|
|
|
|
|
|
<br>
|
2002-09-29 23:42:38 +02:00
|
|
|
|
<br>
|
|
|
|
|
|
<br>
|
2002-09-16 19:13:10 +02:00
|
|
|
|
<br>
|
|
|
|
|
|
</body>
|
|
|
|
|
|
</html>
|
