Greetings. Thought this quick outline might be of use to someone using Ubuntu. I setup my IPV6 subnet today. I did the following: 1) installed radvd from the repo 2) I edited radvd with my /48 prefix (note that you put the /48 in radvd as a /64) prefix 2001:4830:152d::/64 { AdvOnLink on; AdvAutonomous on; AdvRouterAddr on; }; 3) I then edited rc.local and added two lines: a) ifconfig eth0 add 2001:4830:152d:0:20e:cff:fe74:b111/64 (edited per post below) I found I had to add an ipv6 address to eth0 from my allocated group in order to get this to work. b) ip -6 ro add 2001:4830:152d::/48 dev lo For addresses in my /48 that I assign, I don't want to go to sixxs and then back down, I want to go direct. This in fact helped me test my subnet setup so that I could issue ping6 commands to the dhcp3 gathered ipv6 addresses on my other systems. Ping times are horrid outside of my network but I have connectivity from computers using my subnet! PING sixxs.net(noc.sixxs.net) 56 data bytes 64 bytes from noc.sixxs.net: icmp_seq=1 ttl=52 time=169 ms 64 bytes from noc.sixxs.net: icmp_seq=2 ttl=52 time=166 ms 64 bytes from noc.sixxs.net: icmp_seq=3 ttl=52 time=166 ms 64 bytes from noc.sixxs.net: icmp_seq=4 ttl=52 time=165 ms 64 bytes from noc.sixxs.net: icmp_seq=5 ttl=52 time=167 ms Inside they are pretty good. PING 2001:4830:152d:0:20e:cff:fe74:b111(2001:4830:152d:0:20e:cff:fe74:b111) 56 data bytes 64 bytes from 2001:4830:152d:0:20e:cff:fe74:b111: icmp_seq=1 ttl=64 time=0.228 ms 64 bytes from 2001:4830:152d:0:20e:cff:fe74:b111: icmp_seq=2 ttl=64 time=0.238 ms 64 bytes from 2001:4830:152d:0:20e:cff:fe74:b111: icmp_seq=3 ttl=64 time=0.136 ms 64 bytes from 2001:4830:152d:0:20e:cff:fe74:b111: icmp_seq=4 ttl=64 time=0.224 ms