I can ping the IPv4 address of the pop, but i cannot ping the IPv6 address. The tunnel was working for over a week, and I've just recieved a subnet and was starting to deploy it on the local network, to complete the tests.. However, it appears that shortly after I received the subnet, the tunnel stopped working, though "aiccu test" seems to indicate that it is running.. I have set up the local subnet, and I can ping through from any machine to the local end of the IPv6 tunnel, I can also ping the pop's IPv4 address. However, I cannot ping the remote end of the tunnel. So I went to my tunnel machine, and tried doing a ping directly on the tunnel, this also did not work.. It seems that the tunnel is not returning packages, I can verify that the tunnel (my end) sees the packets. I am a bit concerned about the traceroute, in that it does not seem to be as stable as I'd like (different points time out differently on repeated runs), so perhaps this is an ISP/routing issue... I'm out of ideas for tracking the problem, so I'm asking for help. As you request in your contact page, here is the information you usually ask for. [root@web ~]# aiccu test Tunnel Information for T63153: POP Id : dkcph01 IPv6 Local : 2001:16d8:dd00:11e::2/64 IPv6 Remote : 2001:16d8:dd00:11e::1/64 Tunnel Type : ayiya Adminstate : enabled Userstate : enabled : sixxs: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1280 qdisc noqueue state UNKNOWN link/sit 192.168.1.50 peer 93.158.77.42 inet6 2001:16d8:dd00:11e::2/64 scope global valid_lft forever preferred_lft forever inet6 fe80::c0a8:132/128 scope link valid_lft forever preferred_lft forever [root@web ~]# ping 93.158.77.42 PING 93.158.77.42 (93.158.77.42) 56(84) bytes of data. 64 bytes from 93.158.77.42: icmp_req=1 ttl=58 time=49.4 ms 64 bytes from 93.158.77.42: icmp_req=2 ttl=58 time=63.8 ms [root@web ~]# ping6 2001:16d8:dd00:11e::2 PING 2001:16d8:dd00:11e::2(2001:16d8:dd00:11e::2) 56 data bytes 64 bytes from 2001:16d8:dd00:11e::2: icmp_seq=1 ttl=64 time=0.110 ms 64 bytes from 2001:16d8:dd00:11e::2: icmp_seq=2 ttl=64 time=0.135 ms 64 bytes from 2001:16d8:dd00:11e::2: icmp_seq=3 ttl=64 time=0.121 ms --- 2001:16d8:dd00:11e::2 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 1999ms rtt min/avg/max/mdev = 0.110/0.122/0.135/0.010 ms [root@web ~]# ping6 2001:16d8:dd00:11e::1 PING 2001:16d8:dd00:11e::1(2001:16d8:dd00:11e::1) 56 data bytes --- 2001:16d8:dd00:11e::1 ping statistics --- 4 packets transmitted, 0 received, 100% packet loss, time 2999ms [root@web ~]# uname -a Linux web.devel.thetroubleshooters.dk 2.6.35.12-88.fc14.x86_64 #1 SMP Thu Mar 31 21:21:57 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux specifically - using Fedora 14 The traceroute bit concerns me, as I don't like a traceroute that seems unstable.. Could this be the indication of the problem ? [root@web ~]# traceroute -n 93.158.77.42 traceroute to 93.158.77.42 (93.158.77.42), 30 hops max, 60 byte packets 1 192.168.1.1 0.370 ms 0.457 ms 0.564 ms 2 * * * 3 * * * 4 * * * 5 * * * 6 93.158.77.42 74.940 ms 74.772 ms 74.705 ms