15.6. Autoconfiguration with IPv6

Problem

You keep hearing about this wonderful autoconfiguration in IPv6. How do you do this?

Solution

Make it easy on yourself, and use the radvd, the router advertising daemon. This simple example /etc/radvd.conf uses the addressing from Recipe 15.3:

	##/etc/radvd.conf
	interface eth0 {
	        AdvSendAdvert on;
	        MinRtrAdvInterval 3;
	        MaxRtrAdvInterval 10;
	        prefix FC00:0:0:1::/64 {
	                AdvOnLink on;
	                AdvAutonomous on;
	                AdvRouterAddr on;
	        };
	};

Save your changes, and restart radvd:

	# /etc/init.d/radvd restart
	Restarting radvd: radvd.

radvd will advertise itself, and clients will automatically pick up new addresses, as the ip command will verify:

	$ ip -6 addr show eth0
	2: eth0: <BROADCAST,MULTICAST,UP,10000> mtu 1500 qlen 1000
	inet6 fc00::1:214:2aff:fe54:67d6/64 scope global dynamic

Discussion

radvd is meant to be simple, so that is really all there is to it. When you're playing around on your test network, you may use any IPv6 address range you want (see the Introduction for more information on these). Just keep in mind that the prefix is the first 64 bits, or the first four quads, and the host portion is also 64 bits. You leave the host portion blank in radvd.conf because the daemon will assign that part.

See Also