shorewall_code/Shorewall-docs/blacklisting_support.htm

96 lines
3.5 KiB
HTML
Raw Normal View History

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Language" content="en-us">
<meta http-equiv="Content-Type"
content="text/html; charset=windows-1252">
<meta name="GENERATOR" content="Microsoft FrontPage 5.0">
<meta name="ProgId" content="FrontPage.Editor.Document">
<title>Blacklisting Support</title>
</head>
<body>
<table border="0" cellpadding="0" cellspacing="0"
style="border-collapse: collapse;" bordercolor="#111111" width="100%"
id="AutoNumber1" bgcolor="#400169" height="90">
<tbody>
<tr>
<td width="100%">
<h1 align="center"><font color="#ffffff">Blacklisting Support</font></h1>
</td>
</tr>
</tbody>
</table>
<p>Shorewall supports two different forms of blacklisting; static and dynamic.</p>
<h2>Static Blacklisting</h2>
<p>Shorewall static blacklisting support has the following configuration parameters:</p>
<ul>
<li>You specify whether you want packets from blacklisted hosts dropped
or rejected using the <a href="Documentation.htm#BLDisposition">BLACKLIST_DISPOSITION</a>
setting in /etc/shorewall/shorewall.conf</li>
<li>You specify whether you want packets from blacklisted hosts logged
and at what syslog level using the <a
href="Documentation.htm#BLLoglevel">BLACKLIST_LOGLEVEL</a> setting in
/etc/shorewall/shorewall.conf</li>
<li>You list the IP addresses/subnets that you wish to blacklist in <a
href="Documentation.htm#Blacklist">/etc/shorewall/blacklist.</a> Beginning
with Shorewall version 1.3.8, you may also specify PROTOCOL and Port numbers/Service
names in the blacklist file.<br>
</li>
<li>You specify the interfaces whose incoming packets you want checked
against the blacklist using the "<a
href="Documentation.htm#Interfaces">blacklist</a>" option in /etc/shorewall/interfaces.</li>
<li>The black list is refreshed from /etc/shorewall/blacklist by the
"<a href="Documentation.htm#Starting">shorewall refresh</a>" command.</li>
</ul>
<h2>Dynamic Blacklisting</h2>
<p>Dynamic blacklisting support was added in version 1.3.2. Dynamic blacklisting
doesn't use any configuration parameters but is rather controlled using
/sbin/shorewall commands:</p>
<ul>
<li>drop <i>&lt;ip address list&gt; </i>- causes packets from the listed
IP addresses to be silently dropped by the firewall.</li>
<li>reject <i>&lt;ip address list&gt; </i>- causes packets from the listed
IP addresses to be rejected by the firewall.</li>
<li>allow <i>&lt;ip address list&gt; </i>- re-enables receipt of packets
from hosts previously blacklisted by a <i>deny</i> or <i>reject</i> command.</li>
<li>save - save the dynamic blacklisting configuration so that it will
be automatically restored the next time that the firewall is restarted.</li>
<li>show dynamic - displays the dynamic blacklisting configuration.</li>
</ul>
<p>Example 1:</p>
<pre> shorewall drop 192.0.2.124 192.0.2.125</pre>
<p><EFBFBD><EFBFBD><EFBFBD> Drops packets from hosts 192.0.2.124 and 192.0.2.125</p>
<p>Example 2:</p>
<pre> shorewall allow 192.0.2.125</pre>
<p><EFBFBD><EFBFBD><EFBFBD> Reenables access from 192.0.2.125.</p>
<p><font size="2">Last updated 10/7/2002 - <a href="support.htm">Tom Eastep</a></font></p>
<p><font face="Trebuchet MS"><a href="copyright.htm"><font size="2">Copyright</font>
<20> <font size="2">2002 Thomas M. Eastep.</font></a></font></p>
<br>
<br>
</body>
</html>