Linux Networking Cookbook

4.3. Setting Up Name Services

Problem

Your LAN is going to have a combination of hosts with static IP addresses and DHCP clients that come and go, especially wireless clients. And, you want DHCP clients to automatically be entered into DNS so they can be accessed by hostname just like the hosts with static IP addresses.

Solution

You don't want much. Fortunately, you can have it all. Pyramid comes with dnsmasq, which handles DHCP and DNS, and automatically enters DHCP clients into DNS. This requires the clients to send their hostnames when they are requesting a DHCP lease. Windows clients do this by default. Most Linux clients do not, so go to Recipe 4.5 to learn about client configuration.

Now, we'll edit /etc/dnsmasq.conf on your Pyramid box. First make the filesystem write able by running /sbin/rw. Copy this example, using your own network name instead of alrac.net, whatever DHCP range you prefer, and your own upstream nameservers:

	pyramid:~# /sbin/rw
	pyramid:~# nano /etc/dnsmasq.conf

	domain-needed
	bogus-priv
	local=/alrac.net/
	expand-hosts
	domain=alrac.net
	interface=br0
	listen-address=127.0.0.1

	#upstream nameservers
	server=22.33.44.2
	server=22.33.44.3

	dhcp-range=lan,192.168.1.100,192.168.1.200,12h
	dhcp-lease-max=100

Next, add all of your hosts that already have static IP addresses to /etc/hosts on your Pyramid box, using only their hostnames and IP addresses. At a minimum, you must have an entry for localhost and your Pyramid router:

 ## /etc/hosts 127.0.0.1 localhost 192.168.1.50 pyramid ...