Month: August 2010

source: http://www.linuxtopia.org/online_books/network_administration_guides/Linux+IPv6-HOWTO/hints-daemons-radvd.html

Router Advertisement Daemon (radvd)

The router advertisement daemon is very useful on a LAN, if clients should be auto-configured. The daemon itself should run on the Linux default IPv6 gateway router (it’s not required that this is also the default IPv4 gateway, so pay attention who on your LAN is sending router advertisements).

You can specify some information and flags which should be contained in the advertisement. Common used are:

• Prefix (needed)
• Lifetime of the prefix
• Frequency of sending advertisements (optional)

After a proper configuration, the daemon sends advertisements through specified interfaces and clients are hopefully receive them and auto-magically configure addresses with received prefix and the default route.

Configuring radvd

Simple configuration

Radvd’s config file is normally /etc/radvd.conf. An simple example looks like following:

interface eth0 {
        AdvSendAdvert on;
        MinRtrAdvInterval 3;
        MaxRtrAdvInterval 10;
        prefix 2001:0db8:0100:f101::/64 {
                AdvOnLink on;
                AdvAutonomous on;
                AdvRouterAddr on;
        };
};

This results on client side in

# ip -6 addr show eth0
3: eth0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 100
    inet6 2001:0db8:100:f101:2e0:12ff:fe34:1234/64 scope global dynamic
       valid_lft 2591992sec preferred_lft 604792sec
    inet6 fe80::2e0:12ff:fe34:1234/10 scope link

Because no lifetime was defined, a very high value was used.