Hello, my tunnel stopped working about 15 minutes ago (1845 hours, GMT+1). Traceroute to the POP works: traceroute to 91.184.37.98 (91.184.37.98), 64 hops max, 52 byte packets 1 83-169-166-218-isp.superkabel.de (83.169.166.218) 10.084 ms 7.492 ms 10.348 ms 2 83-169-177-54-isp.superkabel.de (83.169.177.54) 12.828 ms 13.690 ms 11.860 ms 3 88-134-204-38-dynip.superkabel.de (88.134.204.38) 12.109 ms 15.556 ms 11.754 ms 4 83-169-128-114.static.superkabel.de (83.169.128.114) 12.667 ms 14.853 ms 12.757 ms 5 83-169-128-97.static.superkabel.de (83.169.128.97) 16.124 ms 14.306 ms 13.550 ms 6 decix.r1.fra3.opencarrier.eu (80.81.192.24) 14.715 ms 14.042 ms 15.550 ms 7 oc-fra.speedpartner.de (194.54.95.218) 255.560 ms 18.559 ms 17.779 ms 8 dedus01.sixxs.net (91.184.37.98) 25.724 ms 26.490 ms 24.337 ms I can ping it on v4, and it's answering, but the tunnel stopped working. I even receive ICMP6 neighbour advertisements from the tunnel: 18:52:30.731883 IP 91.66.72.79 > 91.184.37.98: IP6 2a01:198:200:a69::2 > 2a01:198:200:a69::1: ICMP6, neighbor solicitation[|icmp6] 18:52:30.750537 IP 91.184.37.98 > 91.66.72.79: IP6 2a01:198:200:a69::1 > 2a01:198:200:a69::2: ICMP6, neighbor advertisement[|icmp6] But don't get any answers back. The aiccu output doesn't show anything wrong: Tunnel Information for T48157: POP Id : dedus01 IPv6 Local : 2a01:198:200:a69::2/64 IPv6 Remote : 2a01:198:200:a69::1/64 Tunnel Type : 6in4-heartbeat Adminstate : enabled Userstate : enabled I'm not even able to ping the v6 endpoint. It's been down a few times in the last week. But I never figured out any errors on my site of the tunnel. Kind Regards, Oliver