The most simple suite for getting started with IPv6 under Linux is probably the Router Advertisement server suite, called radvd. Configuration is quite simple, as the radvd.conf only needs a few lines:
Afterwards (re)start the radvd and you’re good to go. You will notice IPv6-capable machines automatically acquiring addresses starting with the prefix you have set in the radvd.conf. For testing IPv6 connectivity, try ‘ping ipv6.google.com’ or under Linux: ‘ping6 ipv6.google.com’.
If you are experiencing problems with certain IPv6 sites not working, despite seeing a successful TCP connection, you might be experiencing the so-called ‘Path MTU problem‘. A dirty work-around for this problem is adding the configuration line ‘AdvLinkMTU 1280’ to the radvd.conf posted above and restarting radvd.