Hi all, i have no idea what i should search for. So i open a new topic. I have a Linux PC running a SIXXS Tunnel and its working fine. I am able to access the IPv6 Internet without any problem. When i connect a PC to eth1 the PC get an IPv6 IP accroding the SIXXS client subnet and is also able to access the internet. When i put an DSLAM with DSL modem in between my Server and the test PC, the Modem get an IP according the SIXXS client subnet and can also ping an ipv6 IP adress. Now the Problem: When i try to ping the same IP which i pingt with the modem itselfe, i can see in wireshark traces on the sixxs and eth1 interface that the packet is going from the testing PC to the internet and is also coming back trough the SIXXS tunnel but it is not forwardet to the eth1. So it looks like that the "route" back is wrong, but how could that be? Does anybody has any idea, what i do have to change on my linux PC? - Iptable is nor running - the desitination IP of the Ping response is the one of the Text PC - on eth1 i can see the outgoing echo requests but nothing is coming back. Thanks for your help. Sebastian