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<title>Starting and Stopping Shorewall</title>
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<h1 align="center"><font color="#ffffff">Starting/Stopping and Monitoring
the Firewall</font></h1>
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<p> If you have a permanent internet connection such as DSL or Cable,
I recommend that you start the firewall automatically at boot. Once
you have installed "firewall" in your init.d directory, simply type
"chkconfig --add firewall". This will start the firewall in run
levels 2-5 and stop it in run levels 1 and 6. If you want to configure
your firewall differently from this default, you can use the "--level"
option in chkconfig (see "man chkconfig") or using your favorite
graphical run-level editor.</p>
<p><strong><u> <font color="#000099"> Important Notes:</font></u></strong><br>
</p>
<ol>
<li>Shorewall startup is disabled by default. Once you have configured
your firewall, you can enable startup by removing the file /etc/shorewall/startup_disabled.
Note: Users of the .deb package must edit /etc/default/shorewall and set
'startup=1'.<br>
</li>
<li>If you use dialup, you may want to start the firewall in your
/etc/ppp/ip-up.local script. I recommend just placing "shorewall restart"
in that script.</li>
</ol>
<p>
</p>
<p> You can manually start and stop Shoreline Firewall using the "shorewall"
shell program: </p>
<ul>
<li>shorewall start - starts the firewall</li>
<li>shorewall stop - stops the firewall</li>
<li>shorewall restart - stops the firewall (if it's running)
and then starts it again</li>
<li>shorewall reset - reset the packet and byte counters
in the firewall</li>
<li>shorewall clear - remove all rules and chains installed
by Shoreline Firewall</li>
<li>shorewall refresh - refresh the rules involving the broadcast
addresses of firewall interfaces and the black and white lists.</li>
</ul>
If you include the keyword <i>debug</i> as the first argument, then a shell
trace of the command is produced as in:<br>
<pre> <font color="#009900"><b>shorewall debug start 2> /tmp/trace</b></font><br></pre>
<p>The above command would trace the 'start' command and place the trace
information in the file /tmp/trace</p>
<p> The "shorewall" program may also be used to monitor the firewall.</p>
<ul>
<li>shorewall status - produce a verbose report about the firewall
(iptables -L -n -v)</li>
<li>shorewall show <i>chain</i> - produce a verbose report about
<i>chain </i>(iptables -L <i>chain</i> -n -v)</li>
<li>shorewall show nat - produce a verbose report about the nat table
(iptables -t nat -L -n -v)</li>
<li>shorewall show tos - produce a verbose report about the mangle
table (iptables -t mangle -L -n -v)</li>
<li>shorewall show log - display the last 20 packet log entries.</li>
<li>shorewall show connections - displays the IP connections currently
being tracked by the firewall.</li>
<li>shorewall
show
tc - displays information
about the traffic control/shaping configuration.</li>
<li>shorewall monitor [ delay ] - Continuously display the firewall
status, last 20 log entries and nat. When the log entry display
changes, an audible alarm is sounded.</li>
<li>shorewall hits - Produces several reports about the Shorewall
packet log messages in the current /var/log/messages file.</li>
<li>shorewall version - Displays the installed version number.</li>
<li>shorewall check - Performs a <u>cursory</u> validation of
the zones, interfaces, hosts, rules and policy files. <font
size="4" color="#ff6666"><b>The "check" command does not parse and validate
the generated iptables commands so even though the "check" command
completes successfully, the configuration may fail to start. See the
recommended way to make configuration changes described below. </b></font>
</li>
<li>shorewall try<i> configuration-directory</i> [<i> timeout</i>
] - Restart shorewall using the specified configuration and if an error
occurs or if the<i> timeout </i> option is given and the new configuration
has been up for that many seconds then shorewall is restarted using
the standard configuration.</li>
<li>shorewall deny, shorewall reject, shorewall accept and shorewall
save implement <a href="blacklisting_support.htm">dynamic blacklisting</a>.</li>
<li>shorewall logwatch (added in version 1.3.2) - Monitors the
<a href="#Conf">LOGFILE </a>and produces an audible alarm when new Shorewall
messages are logged.</li>
</ul>
Finally, the "shorewall" program may be used to dynamically alter the contents
of a zone.<br>
<ul>
<li>shorewall add <i>interface</i>[:<i>host]</i> <i>zone </i>- Adds the
specified interface (and host if included) to the specified zone.</li>
<li>shorewall delete <i>interface</i>[:<i>host]</i> <i>zone </i>- Deletes
the specified interface (and host if included) from the specified zone.</li>
</ul>
<blockquote>Examples:<br>
<blockquote><font color="#009900"><b>shorewall add ipsec0:192.0.2.24 vpn1</b></font>
-- adds the address 192.0.2.24 from interface ipsec0 to the zone vpn1<br>
<font color="#009900"><b> shorewall delete ipsec0:192.0.2.24 vpn1</b></font>
-- deletes the address 192.0.2.24 from interface ipsec0 from zone vpn1<br>
</blockquote>
</blockquote>
<p> The <b>shorewall start</b>, <b>shorewall restart, shorewall check </b>�and
<b>shorewall try </b>commands allow you to specify which <a
href="configuration_file_basics.htm#Configs"> Shorewall configuration</a>
to use:</p>
<blockquote>
<p> shorewall [ -c <i>configuration-directory</i> ] {start|restart|check}<br>
shorewall try <i>configuration-directory</i></p>
</blockquote>
<p> If a <i>configuration-directory</i> is specified, each time that Shorewall
is going to use a file in /etc/shorewall it will first look in the <i>configuration-directory</i>
. If the file is present in the <i>configuration-directory</i>, that file
will be used; otherwise, the file in /etc/shorewall will be used.</p>
<p> When changing the configuration of a production firewall, I recommend
the following:</p>
<ul>
<li><font color="#009900"><b>mkdir /etc/test</b></font></li>
<li><font color="#009900"><b>cd /etc/test</b></font></li>
<li><copy any files that you need to change from /etc/shorewall
to . and change them here></li>
<li><font color="#009900"><b>shorewall -c . check</b></font></li>
<li><correct any errors found by check and check again></li>
<li><font color="#009900"><b>/sbin/shorewall try .</b></font></li>
</ul>
<p> If the configuration starts but doesn't work, just "shorewall restart"
to restore the old configuration. If the new configuration fails to start,
the "try" command will automatically start the old one for you.</p>
<p> When the new configuration works then just </p>
<ul>
<li><font color="#009900"><b>cp * /etc/shorewall</b></font></li>
<li><font color="#009900"><b>cd</b></font></li>
<li><font color="#009900"><b>rm -rf /etc/test</b></font></li>
</ul>
<p><font size="2"> Updated 1/9/2003 - <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">2001, 2002, 2003 Thomas M. Eastep.</font></a></font></p>
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