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<title>Blacklisting Support</title>
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<h1 align="center"><font color="#ffffff">Blacklisting Support</font></h1>
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<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><ip address list> </i>- causes packets from the listed
IP addresses to be silently dropped by the firewall.</li>
<li>reject <i><ip address list> </i>- causes packets from the
listed IP addresses to be rejected by the firewall.</li>
<li>allow <i><ip address list> </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>
Dynamic blacklisting is <u>not</u> dependent on the "blacklist" option in
/etc/shorewall/interfaces.<br>
<p>Example 1:</p>
<pre> <b><font color="#009900">shorewall drop 192.0.2.124 192.0.2.125</font></b></pre>
<p>��� Drops packets from hosts 192.0.2.124 and 192.0.2.125</p>
<p>Example 2:</p>
<pre> <b><font color="#009900">shorewall allow 192.0.2.125</font></b></pre>
<p>��� Reenables access from 192.0.2.125.</p>
<p><font size="2">Last updated 2/7/2003 - <a href="support.htm">Tom Eastep</a></font></p>
<p><font face="Trebuchet MS"><a href="copyright.htm"><font size="2">Copyright</font>
� <font size="2">2002, 2003 Thomas M. Eastep.</font></a></font></p>
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