Hello, on my tunnel end I habe configured this: in /etc/sysconfig/network-scripts/ifcfg-eth0 I added this IPV6INIT=yes IPV6ADDR=lan-prefix::1 IPV6ADDR_SECONDARIES="fe80::1" IPV6_AUTOCONF=no IPV6_ROUTER=yes /etc/sysconfig/network-scripts/ifcfg-sit1 is this TYPE=SIT NAME=sit1 ONBOOT=yes DEVICE=sit1 BOOTPROTO=none IPV6INIT=yes IPV6TUNNELIPV4=ipv4-of-tunnel-at-he IPV6TUNNELIPV4LOCAL=myipv4 IPV6ADDR=tunnel-prefix::2 in /etc/sysconfig/network I added this: NETWORKING_IPV6="yes" IPV6FORWARDING="yes" IPV6_DEFAULTGW=tunnel-prefix::1 IPV6_DEFAULTDEV=sit1 everything works fine, but can someone explain this behaviour: traceroute6 www.google.com doing this on this CentOS-Box, I have tunnel-prefix::1 at the first hop as expected; doing this on another Linux (CentOS), I have the CentOS-Box at the first hop and tunnel-prefix::1 at the 2nd hop as expected, but doing this on a Windows, there I have tunnel-prefix::1 at the 2nd and the 3rd hop, why? (the same with my own 6in4-tunnel) Thanks, Walter