source: connect/dhcp/bootscripts.xml@ 58a6bfc

<sect1 id="dhcpclient" xreflabel="Configuring the LFS bootscripts to support DHCP clients">
<?dbhtml filename="configdhcp.html" dir="connect"?>
<title>Configuring the <acronym>LFS</acronym> bootscripts to support <acronym>DHCP</acronym> clients</title>

<sect2><title>Config files</title>
<para><filename>/etc/sysconfig/network</filename>,
<filename>/etc/sysconfig/network-devices/ifup-eth0</filename>,
<filename>/etc/sysconfig/network-devices/ifdown-eth0</filename>,
<filename>/etc/sysconfig/network-devices/ifconfig.eth0</filename></para>
</sect2>

<sect2><title>Configuration Information</title>

<para>Note that on this and the following pages, we 
use <emphasis role="strong">eth0</emphasis> as the example interface.
If you want to configure a different (or more than one) interface, simply 
replace <emphasis role="strong">eth0</emphasis> with the interface you wish to 
use.</para>

<para>These instructions will convert the configuration files from
<acronym>LFS</acronym> (a static configuration) to a configuration using the 
<acronym>DHCP</acronym> protocol. Note that static and
<acronym>DHCP</acronym>-based interfaces can co-exist on a
<acronym>LFS</acronym> system.  To do this, you should only make the 
alterations to those interfaces which need to support
<acronym>DHCP</acronym>.  All of the instructions on this page are applicable
no matter which <acronym>DHCP</acronym> client you intend to use.</para>

<para>If the interface you intend to use as your default gateway is going to 
use <acronym>DHCP</acronym>, the first step is to remove the <envar>GATEWAY
</envar> and <envar>GATEWAY_IF</envar> variables 
from <filename>/etc/sysconfig/network</filename>.  This will only need to be
done once.</para>

<screen><userinput><command>cd /etc/sysconfig &amp;&amp;
cp network network.bak &amp;&amp;
sed "s/GATEWAY/# GATEWAY/" network.bak > network</command></userinput></screen>

<para>You then need to create scripts which will override the default
network scripts and provide <acronym>DHCP</acronym> support.  These two scripts 
are generic and so for use with both <acronym>DHCP</acronym> clients.  First, 
the <filename>ifup-eth0</filename> script:</para>

<screen><userinput><command>cat &gt; /etc/sysconfig/network-devices/ifup-eth0 &lt;&lt; "EOF" </command>
#!/bin/sh

source /etc/sysconfig/rc || exit
source $rc_functions || exit
source $network_devices/ifconfig.eth0 || exit

echo "Bringing up the eth0 interface..."
modprobe eth0
loadproc $DHCP_PROG $DHCP_START
<command>EOF</command></userinput></screen>

<para>Then the <filename>ifdown-eth0</filename> script:</para>

<screen><userinput><command>cat &gt; /etc/sysconfig/network-devices/ifdown-eth0 &lt;&lt; "EOF" </command>
#!/bin/sh

source /etc/sysconfig/rc || exit
source $rc_functions || exit
source $network_devices/ifconfig.eth0 || exit

echo "Bringing down the eth0 interface..."
$DHCP_PROG $DHCP_STOP
evaluate_retval
<command>EOF</command></userinput></screen>

<para>Next, we need to make corrections to the 
<filename>/etc/hosts</filename> file.  Be sure to replace 
<emphasis role="strong">HOSTNAME</emphasis> and
<emphasis role="strong">DOMAIN_NAME</emphasis> with apropriate values.</para>

<screen><userinput><command>mv -f /etc/hosts /etc/hosts.bak &amp;&amp;
cat &gt; /etc/hosts &lt;&lt; "EOF" </command>
# Begin /etc/hosts

127.0.0.1 HOSTNAME HOSTNAME.DOMAIN_NAME localhost localhost.localdomain

# End /etc/hosts
<command>EOF</command></userinput></screen>

<para>Finally, we need to make the scripts executable:</para>

<screen><userinput><command>chmod 755 /etc/sysconfig/network-devices/ifup-eth0 &amp;&amp;
chmod 755 /etc/sysconfig/network-devices/ifdown-eth0</command></userinput></screen>

<warning><para>
This script, in it's current state, <emphasis>will</emphasis> cause an
error at shutdown.  ATM, It is best to just live with the error.  The
network scripts for LFS and BLFS are currently being revised.  In the
interim, you can use a simple workaround to rid yourself of the error.
Move K80network in your stop scripts to K49network.  You must be
absolutely certain, however, that you have all network filesystems
unmounted before this script is executed.
</para></warning>

</sect2>

</sect1>