It worked well for almost two days but since yesterday evening I can neither assign an ipv4 nor an ipv6 address to it. I am very sure i did not change one single bit. I am using Gentoo Linux with kernel version 2.6.6 #5 and verion 2.4.7.20010824-r5 of the iproute2 utilities. I am using the following script to create the tunnel device: -------------- snip ------------------------ #Create a tunnel called sixxs: ip tunnel add sixxs mode sit local $4 remote 212.224.0.188 #$4 = IP address of ppp0 (dsl device). it it definitely passed to the script! #Bring the tunnel interface 'sixxs' up: ip link set sixxs up #Fix MTU and TTL ip link set mtu 1280 dev sixxs ip tunnel change sixxs ttl 64 #Configure your IPv6 endpoint on the tunnel: ip -6 addr add 2001:6f8:900:2f4::2/64 dev sixxs #Route your IPv6 traffic via the SixXS POP: ip -6 ro add default via 2001:6f8:900:2f4::1 dev sixxs --------------- snap ----------------------------- This is exactly what i am told to use by the FAQ-section and it worked well for almost two days. Now i get the following output after calling the script and "ifconfig sixxs": sixxs Link encap:IPv6-in-IPv4 UP POINTOPOINT RUNNING NOARP MTU:1280 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:47 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:0 (0.0 b) TX bytes:6730 (6.5 Kb) As you can see, there is no address assigned to it. There is also nothing logged despite one line: "Aug 9 15:51:24 [kernel] Disabled Privacy Extensions on device c216ac00(sixxs)". That's all. Of course i cannot ping any ipv6 address except local ones. The heartbeat-client sends the following line to the log everytime i restart the pppoe-connection (rp-pppoe): "Aug 9 14:49:59 [heartbeat-client] IP address change to 217.81.91.253 detected, reconfiguring_". My heartbeat.conf: os "linux" ipv4_interface "ppp0" ipv4_pop "deham01.sixxs.net" ipv6_interface "sixxs" ipv6_pop "2001:6f8:900:2f4::1" ipv6_local "2001:6f8:900:2f4::2" ipv6_prefixlen 64 hb_password "-expletive deleted-" hb_sendinterval 60 hb_timeout 300 A protocol 41 dump revealed that there is no packet being transmitted through the tunnel. I tried to ping the end point and several other working ipv6 hosts. tcpdump noted that there is no ipv4 address assigned to the tunnel device so i can only ping it's local ipv6 address (2001:6f8:900:2f4::2). I also tried to correclty sync my computer's time but i think this is not the problem. I am using the following time zone: "/usr/share/zoneinfo/right/Europe/Berlin". I synced it using "/usr/bin/rdate -s ntp0.fau.de" with no effect on the problem. Looks like i couldn't get a clue if I were drenched in clue pheromones, dancing in a clue field in the middle of clue mating season, wearing a clue suit, and shouting, "Clooo! Cloooo! ;(