Linux Networking Cookbook

4.5. Configuring Linux and Windows Static DHCP Clients

Problem

What with having both Linux and Windows clients, and various Linux distributions that like to do things their own way, you're a bit befuddled as to how to configure them to have dnsmasq give them static IP addresses.

Solution

The key to getting static IP addresses from DHCP is for the clients to send their hostnames to the DHCP server when they request a lease.

Windows 2000, 2003, and XP clients do this automatically. All you do is configure them for DHCP in the usual manner.

First, on all Linux machines, make sure there is nothing in /etc/hosts other than the localdomain entry.

Most Linux distributions are not configured to send the hostname by default. To fix this, add one line to their DHCP client files. On Debian, this is the /etc/dhcp3/dhclient.conf file. This example is for the computer named Penguina:

	send host-name "penguina";

You must also enter the hostname in /etc/hostname:

	penguina

Just the hostname and nothing else. Then, set up the normal DHCP configuration in /etc/network/interfaces, like this:

	##/etc/network/interfaces
	auto lo
	iface lo inet loopback

	auto eth0
	iface eth0 inet dhcp

On Fedora, each interface gets its own DHCP client file, like /etc/dhclient-eth1. You may need to create this file. This takes the same send host-name "penguina"; entry. Then, add this line to /etc/sysconfig/network-scripts/ifcfg-eth0:

	DHCP_HOSTNAME=penguina

Make sure the HOSTNAME line in /etc/sysconfig/network is empty.

The sure way to ...