I read carefully the reporting problems checklist, so here my verbose ticket :) My tunnel stopped working and I cant ping anymore the other side of the tunnel. Running AICCU test it stops at the following test: ###### [6/8] Ping the IPv6 Remote/PoP Inner Tunnel Endpoint (2001:1418:100:280::1) I tried from different servers I have and no one is able to make the tunnel and ping the other endpoint. Here the verbose output of aiccu start: tuscolo ~ # aiccu start /etc/aiccu.conf sock_getline() : "200 SixXS TIC Service on noc.sixxs.net ready (http://www.sixxs.net)" sock_printf() : "client TIC/draft-00 AICCU/2007.01.15-console-linux Linux/2.6.25-gentoo-r9" sock_getline() : "200 Client Identity accepted" sock_printf() : "get unixtime" sock_getline() : "200 1236715081" sock_printf() : "starttls" sock_getline() : "400 This service is not SSL enabled (yet)" TIC Server does not support TLS but TLS is not required, continuing sock_printf() : "username SPG1-SIXXS" sock_getline() : "200 Choose your authentication challenge please" sock_printf() : "challenge md5" sock_getline() : "200 9b88aeb0d80348318c014e573943d3d6" sock_printf() : "authenticate md5 0681ee915d7e69fdf47b6f06ff855848" sock_getline() : "200 Succesfully logged in using md5 as SPG1-SIXXS (Saverio Proto) from 2001:7b8:3:4f:202:b3ff:fe46:bec" sock_printf() : "tunnel show T16467" sock_getline() : "201 Showing tunnel information for T16467" sock_getline() : "TunnelId: T16467" sock_getline() : "Type: ayiya" sock_getline() : "IPv6 Endpoint: 2001:1418:100:280::2" sock_getline() : "IPv6 POP: 2001:1418:100:280::1" sock_getline() : "IPv6 PrefixLength: 64" sock_getline() : "Tunnel MTU: 1280" sock_getline() : "Tunnel Name: My First Tunnel" sock_getline() : "POP Id: ittrn01" sock_getline() : "IPv4 Endpoint: ayiya" sock_getline() : "IPv4 POP: 213.254.12.34" sock_getline() : "UserState: enabled" sock_getline() : "AdminState: enabled" sock_getline() : "Password: xxxxx" sock_getline() : "Heartbeat_Interval: 60" sock_getline() : "202 Done" Succesfully retrieved tunnel information for T16467 sock_printf() : "QUIT The End Of Love" Tunnel Information for T16467: POP Id : ittrn01 IPv6 Local : 2001:1418:100:280::2/64 IPv6 Remote : 2001:1418:100:280::1/64 Tunnel Type : ayiya Adminstate : enabled Userstate : enabled [AYIYA-start] : Anything in Anything (draft-02) [AYIYA-tun->tundev] : (Socket to TUN) started My POP is ittrn01, detailed information of the tunnel: T16467ittrn01 - ITgateayiya2001:1418:100:280::2My First TunnelEnabled My computer is running Gentoo Linux, here is uname -a : Linux tuscolo.ninux.org 2.6.25-gentoo-r9 #2 Tue Mar 3 17:12:39 CET 2009 i686 Intel(R) Pentium(R) 4 CPU 2.00GHz GenuineIntel GNU/Linux Interface description: tuscolo ~ # ip addr show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 brd 127.255.255.255 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:04:76:25:08:8e brd ff:ff:ff:ff:ff:ff inet6 fe80::204:76ff:fe25:88e/64 scope link valid_lft forever preferred_lft forever 3: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:02:b3:97:71:67 brd ff:ff:ff:ff:ff:ff inet 192.168.3.214/24 brd 192.168.3.255 scope global eth0 inet6 2001:1418:1a0::1/64 scope global valid_lft forever preferred_lft forever inet6 fe80::202:b3ff:fe97:7167/64 scope link valid_lft forever preferred_lft forever 4: teql0: <NOARP> mtu 1500 qdisc noop state DOWN qlen 100 link/void 5: tunl0: <NOARP> mtu 1480 qdisc noop state DOWN link/ipip 0.0.0.0 brd 0.0.0.0 6: gre0: <NOARP> mtu 1476 qdisc noop state DOWN link/gre 0.0.0.0 brd 0.0.0.0 7: sit0: <NOARP> mtu 1480 qdisc noop state DOWN link/sit 0.0.0.0 brd 0.0.0.0 8: ip6tnl0: <NOARP> mtu 1460 qdisc noop state DOWN link/tunnel6 :: brd :: 50: nk_tap_saverio: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 500 link/ether 00:ff:f4:82:cf:48 brd ff:ff:ff:ff:ff:ff inet 10.0.0.1/8 brd 10.255.255.255 scope global nk_tap_saverio inet6 fe80::2ff:f4ff:fe82:cf48/64 scope link valid_lft forever preferred_lft forever 102: ppp0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1492 qdisc pfifo_fast state UNKNOWN qlen 3 link/ppp inet 87.17.211.239 peer 192.168.100.1/32 scope global ppp0 104: tap0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 100 link/ether 00:ff:ba:1d:4d:81 brd ff:ff:ff:ff:ff:ff inet 10.0.1.10/24 brd 10.0.1.255 scope global tap0 inet6 fe80::2ff:baff:fe1d:4d81/64 scope link valid_lft forever preferred_lft forever 110: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1280 qdisc pfifo_fast state UNKNOWN qlen 500 link/[65534] inet6 2001:1418:100:280::2/64 scope global valid_lft forever preferred_lft forever inet6 fe80::1418:100:280:2/64 scope link valid_lft forever preferred_lft forever tuscolo ~ # Firewall description: tuscolo ~ # iptables -L -v Chain INPUT (policy ACCEPT 32M packets, 25G bytes) pkts bytes target prot opt in out source destination 0 0 DROP tcp -- ppp0 any anywhere anywhere tcp dpt:9091 0 0 DROP tcp -- ppp0 any anywhere anywhere tcp dpt:9090 0 0 DROP tcp -- ppp0 any anywhere anywhere tcp dpt:9092 0 0 DROP tcp -- ppp0 any anywhere anywhere tcp dpt:https 81 6024 DROP tcp -- ppp0 any anywhere anywhere tcp dpt:http 235 12124 DROP tcp -- ppp0 any anywhere anywhere tcp dpt:netbios-ssn Chain FORWARD (policy ACCEPT 1072K packets, 378M bytes) pkts bytes target prot opt in out source destination 4069 236K TCPMSS tcp -- any any anywhere anywhere tcp flags:SYN,RST/SYN TCPMSS clamp to PMTU Chain OUTPUT (policy ACCEPT 30M packets, 23G bytes) pkts bytes target prot opt in out source destination tuscolo ~ # iptables -t nat -L -v Chain PREROUTING (policy ACCEPT 175K packets, 13M bytes) pkts bytes target prot opt in out source destination 54695 2878K REDIRECT tcp -- any any anywhere anywhere tcp dpt:http redir ports 8080 Chain POSTROUTING (policy ACCEPT 243K packets, 20M bytes) pkts bytes target prot opt in out source destination 217K 14M MASQUERADE all -- any ppp0 anywhere anywhere Chain OUTPUT (policy ACCEPT 433K packets, 31M bytes) pkts bytes target prot opt in out source destination tuscolo ~ # IPv4 Traceroute to the PoP: ####### [3/8] Traceroute to the PoP (213.254.12.34) over IPv4 ### This traceroute should reach the PoP ### In case this traceroute fails then you have no connectivity ### to the PoP and this is most probably the problem traceroute to 213.254.12.34 (213.254.12.34), 30 hops max, 40 byte packets 1 * * * 2 host129-61-static.40-88-b.business.telecomitalia.it (88.40.61.129) 232.425 ms 234.106 ms 236.994 ms 3 r-rm214-vl14.opb.interbusiness.it (80.21.6.29) 239.953 ms 241.876 ms 244.843 ms 4 151.99.98.166 (151.99.98.166) 247.781 ms * * 5 * * * 6 * r-to70-r-to89.opb.interbusiness.it (151.99.98.17) 59.235 ms 59.836 ms 7 r-to89-r-to70.opb.interbusiness.it (151.99.98.18) 57.534 ms 57.595 ms 58.609 ms 8 itgate-pub.topix.it (194.116.96.4) 60.347 ms 59.324 ms 58.538 ms 9 if-0-0.charleston.CBQ.TRN.itgate.net (213.254.0.13) 56.473 ms 58.665 ms 58.330 ms 10 frejus.ITgate.net (213.254.12.34) 60.379 ms 58.847 ms 59.465 ms IPv6 Routing table ###### tuscolo ~ # ip -6 route show 2001:1418:100:280::/64 dev tun0 metric 256 expires -6sec mtu 1280 advmss 1220 hoplimit 4294967295 2001:1418:1a0::/64 dev eth0 metric 256 expires -2487364sec mtu 1500 advmss 1440 hoplimit 4294967295 fe80::/64 dev eth0 metric 256 expires -2487367sec mtu 1500 advmss 1440 hoplimit 4294967295 fe80::/64 dev nk_tap_saverio metric 256 expires -2137881sec mtu 1500 advmss 1440 hoplimit 4294967295 fe80::/64 dev eth1 metric 256 expires -1685507sec mtu 1500 advmss 1440 hoplimit 4294967295 fe80::/64 dev tap0 metric 256 expires -1079472sec mtu 1500 advmss 1440 hoplimit 4294967295 fe80::/64 dev tun0 metric 256 expires -5sec mtu 1280 advmss 1220 hoplimit 4294967295 default via 2001:1418:100:280::1 dev tun0 metric 1024 expires -5sec mtu 1280 advmss 1220 hoplimit 4294967295 tuscolo ~ #

I did report all the necessary information but this ticket did not get any reply since several weeks :( Can I do anything else to solve this problem ?