Can you check on the host /proc/sys/net/ipv4/conf/dummy0/forwarding for its value? Try a `ping6 2001:470:d600::1` from the VM and do a `tcpdump -i dummy0 icmp6` on the host. Check for neighbor sollicitation/advertisements >> dummy0 is assigned to a vmware-bridge, that is connected to a debian lenny >> guest. You say dummy0 is a vmware-bridge... what does `brctl` on the host say about that? Greetings, Gerdriaan Mulder