Hi, I've setup a tunnel to SixX and all is working, I then have a route coming to my cisco 3640 from cisco for a /48 and that appears to be working, however when assigning an IP to my debian linux, I can only appear to ping IP's on the cisco 3640. interface Tunnel0 description *** SixXS IPv6 NZ Tunnel *** no ip address ipv6 address 2001:4428:200:A::2/64 ipv6 enable tunnel source 60.234.68.2 tunnel destination 202.21.136.122 tunnel mode ipv6ip ! interface FastEthernet1/0.10 description VPN IP encapsulation dot1Q 10 ip address 60.234.68.2 255.255.255.224 ip nat outside ip virtual-reassembly ipv6 address 2001:4428:207::1:1/126 ! interface FastEthernet1/0.32 encapsulation dot1Q 32 ipv6 address 2001:4428:207::1/127 ipv6 dhcp server SixXs ! ipv6 route ::/0 2001:4428:200:A::1 Then the linux: voip:~# ifconfig eth0 Link encap:Ethernet HWaddr 00:A0:C9:E1:63:B7 inet addr:60.234.68.5 Bcast:60.234.68.31 Mask:255.255.255.224 inet6 addr: 2001:4428:207::1:2/126 Scope:Global inet6 addr: fe80::2a0:c9ff:fee1:63b7/64 Scope:Link UP BROADCAST RUNNING MULTICAST DYNAMIC MTU:1500 Metric:1 RX packets:193488557 errors:0 dropped:0 overruns:0 frame:1 TX packets:247793820 errors:0 dropped:0 overruns:0 carrier:1185 collisions:3243 txqueuelen:1000 RX bytes:4653965 (4.4 MiB) TX bytes:391001292 (372.8 MiB) Interrupt:11 And a route was added with "ip -6 route add ::/0 via 2001:4428:207::1:1" Now troubleshooting: From this ping you can see I can hit the fa1/0.10 interface http://www.berkom.blazing.de/tools/ping.cgi?STR=2001%3A4428%3A207%3A%3A1%3A1 From this ping attempt you can see I cant reach the linux box. http://www.berkom.blazing.de/tools/ping.cgi?STR=2001%3A4428%3A207%3A%3A1%3A2 From the linux machine I can ping all cisco ipv6 interfaces (notice diff destination IP's) however cannot ping the other end of the tunnel device. 64 bytes from 2001:4428:207::1:1: icmp_seq=2 ttl=64 time=1.08 ms 64 bytes from 2001:4428:207::1: icmp_seq=1 ttl=64 time=1.19 ms 64 bytes from 2001:4428:200:a::2: icmp_seq=1 ttl=64 time=1.06 ms Any help would be appreciated. Thanks Barry