I have requested a tunnel back in 1997 and first used it as a ayiya tunnel. As far as I can remember, everything worked fine. A few days back I changed the tunnel to a 6in4-static and use a Cisco 1841 to connect to it. With the C1841 I can ping the pop ipv6 address 2001:610:600:375::1 at the other end of the tunnel every time I try. When I however try to ping the ipv6 address configured on the cisco 2001:610:600:375::2, at first it works fine but after a while it times out. When I've pinged the pop ipv6 address from the Cisco console, I can also ping the ipv6 adrress on the Cisco again. It looks like the tunnel falls asleep after a while. The tunnel config on the Cisco: interface Tunnel0 description *** IPv6 uplink to SixXS *** no ip address ipv6 address 2001:610:600:375::2/64 ipv6 enable ipv6 mtu 1280 tunnel source FastEthernet0/0 tunnel destination 192.87.102.107 tunnel mode ipv6ip end router#sh int tu0 Tunnel0 is up, line protocol is up Hardware is Tunnel Description: *** IPv6 uplink to SixXS *** The tunnel stays up, no disconnects what so ever. If you need any additional information whatsoever, please let me know. Thanks in advance, Regards, JMX3-SIXXS Jeroen Maatman