<HTML ><HEAD ><TITLE >Troubleshooting: Questions and Answers</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.60"><LINK REL="HOME" TITLE="Setting up IP Aliasing on A Linux Machine Mini-HOWTO" HREF="index.html"><LINK REL="PREVIOUS" TITLE="Commands" HREF="commands.html"><LINK REL="NEXT" TITLE="Acknowledgements" HREF="acknowledgements.html"></HEAD ><BODY CLASS="SECT1" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >Setting up IP Aliasing on A Linux Machine Mini-HOWTO</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="commands.html" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="acknowledgements.html" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="TROUBLESHOOTING" >3. Troubleshooting: Questions and Answers</A ></H1 ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="KEEPSETTINGS" >3.1. Question: How can I keep the settings through a reboot?</A ></H2 ><P >Answer: Whether you are using BSD-style or SysV-style (Redhat™ for example) <B CLASS="COMMAND" >init</B >, you can always include it in <TT CLASS="FILENAME" >/etc/rc.d/rc.local</TT >. Here's what I have on my SysV init system (Redhat™ 3.0.3 and 4.0):</P ><P >My <TT CLASS="FILENAME" >/etc/rc.d/rc.local</TT >: (edited to show the relevant portions)</P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" WIDTH="100%" ><TR ><TD ><PRE CLASS="SCREEN" >#setting up IP alias interfaces echo "Setting 172.16.3.1, 172.16.3.10, 172.16.3.100 IP Aliases ..." /sbin/ifconfig lo 127.0.0.1 /sbin/ifconfig eth0 up /sbin/ifconfig eth0 172.16.3.1 /sbin/ifconfig eth0:0 172.16.3.10 /sbin/ifconfig eth0:1 172.16.3.100 #setting up the routes echo "Setting IP routes ..." /sbin/route add -net 127.0.0.0 /sbin/route add -net 172.16.3.0 dev eth0 /sbin/route add -host 172.16.3.1 eth0 /sbin/route add -host 172.16.3.10 eth0:0 /sbin/route add -host 172.16.3.100 eth0:1 /sbin/route add default gw 172.16.3.200 # </PRE ></TD ></TR ></TABLE ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="SETTINGUPMAIL" >3.2. Question: How do I set up the IP aliased machine to receive e-mail on the various aliased IP addresses (on a machine using sendmail)?</A ></H2 ><P >Answer: Create (if it doesn't already exist) a file called, <TT CLASS="FILENAME" >/etc/mynames.cw</TT >,for example. The file does not have to be this exact name nor in the <TT CLASS="FILENAME" >/etc directory</TT >.</P ><P >In that file, place the official domain names of the aliased IP addresses. If these aliased IP addresses do not have a domain name, then you can place the IP address itself.</P ><P > The <TT CLASS="FILENAME" >/etc/mynames.cw</TT > might look like this:</P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" WIDTH="100%" ><TR ><TD ><PRE CLASS="PROGRAMLISTING" ># /etc/mynames.cw - include all aliases for your machine here; # is a comment domain.one.net domain.two.com domain.three.org 4.5.6.7 </PRE ></TD ></TR ></TABLE ><P >In your <TT CLASS="FILENAME" >sendmail.cf</TT > file, where it defines a file class macro Fw, add the following:</P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" WIDTH="100%" ><TR ><TD ><PRE CLASS="SCREEN" > ################## # local info # ################## # file containing names of hosts for which we receive email Fw/etc/mynames.cw </PRE ></TD ></TR ></TABLE ><P >That should do it. Test out the new setting by invoking sendmail in test mode. The following is an example:</P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" WIDTH="100%" ><TR ><TD ><PRE CLASS="SCREEN" >ganymede$ /usr/lib/sendmail -bt ADDRESS TEST MODE (ruleset 3 NOT automatically invoked) Enter < ruleset> < address> > 0 me@4.5.6.7 rewrite: ruleset 0 input: me @ 4 . 5 . 6 . 7 rewrite: ruleset 98 input: me @ 4 . 5 . 6 . 7 rewrite: ruleset 98 returns: me @ 4 . 5 . 6 . 7 rewrite: ruleset 97 input: me @ 4 . 5 . 6 . 7 rewrite: ruleset 3 input: me @ 4 . 5 . 6 . 7 rewrite: ruleset 96 input: me < @ 4 . 5 . 6 . 7 > rewrite: ruleset 96 returns: me < @ 4 . 5 . 6 . 7 . > rewrite: ruleset 3 returns: me < @ 4 . 5 . 6 . 7 . > rewrite: ruleset 0 input: me < @ 4 . 5 . 6 . 7 . > rewrite: ruleset 98 input: me < @ 4 . 5 . 6 . 7 . > rewrite: ruleset 98 returns: me < @ 4 . 5 . 6 . 7 . > rewrite: ruleset 0 returns: $# local $: me rewrite: ruleset 97 returns: $# local $: me rewrite: ruleset 0 returns: $# local $: me > 0 me@4.5.6.8 rewrite: ruleset 0 input: me @ 4 . 5 . 6 . 8 rewrite: ruleset 98 input: me @ 4 . 5 . 6 . 8 rewrite: ruleset 98 returns: me @ 4 . 5 . 6 . 8 rewrite: ruleset 97 input: me @ 4 . 5 . 6 . 8 rewrite: ruleset 3 input: me @ 4 . 5 . 6 . 8 rewrite: ruleset 96 input: me < @ 4 . 5 . 6 . 8 > rewrite: ruleset 96 returns: me < @ 4 . 5 . 6 . 8 > rewrite: ruleset 3 returns: me < @ 4 . 5 . 6 . 8 > rewrite: ruleset 0 input: me < @ 4 . 5 . 6 . 8 > rewrite: ruleset 98 input: me < @ 4 . 5 . 6 . 8 > rewrite: ruleset 98 returns: me < @ 4 . 5 . 6 . 8 > rewrite: ruleset 95 input: < > me < @ 4 . 5 . 6 . 8 > rewrite: ruleset 95 returns: me < @ 4 . 5 . 6 . 8 > rewrite: ruleset 0 returns: $# smtp $@ 4 . 5 . 6 . 8 $: me < @ 4 . 5 . 6 . 8 > rewrite: ruleset 97 returns: $# smtp $@ 4 . 5 . 6 . 8 $: me < @ 4 . 5 . 6 . 8 > rewrite: ruleset 0 returns: $# smtp $@ 4 . 5 . 6 . 8 $: me < @ 4 . 5 . 6 . 8 > ></PRE ></TD ></TR ></TABLE ><P >Notice when I tested me@4.5.6.7, it delivered the mail to the local machine, while me@4.5.6.8 was handed off to the smtp mailer. That is the correct response.</P ><P >You are all set now.</P ></DIV ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="commands.html" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="acknowledgements.html" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Commands</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" > </TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Acknowledgements</TD ></TR ></TABLE ></DIV ></BODY ></HTML >