Hello, It seems that there is problem with subnet 2001:648:2530::/48 (R30309). To my understanding it seems like packets for this subnet are not routed to tunnel T67241 or that packets from that subnet are firewaled (most likely). The subnet is listed as Enabled. Using traceroute (in fact, mtr), ipv6.google.com is reachable using the tunnel address while it is unreachable using an address from the subnet. Both traceroutes are performed from the exact same machine. tcpdumps bellow are from the tunnel interface. This: mtr -6n --address 2001:648:2530:1::1 ipv6.google.com Results in this: 16:57:34.359623 IP6 2001:648:2530:1::1 > 2a00:1450:4001:c01::93: ICMP6, echo request, seq 59520, length 64 16:57:34.369314 IP6 2001:648:ff00:12::1 > 2001:648:2530:1::1: ICMP6, time exceeded in-transit for 2a00:1450:4001:c01::93, length 112 16:57:34.459829 IP6 2001:648:2530:1::1 > 2a00:1450:4001:c01::93: ICMP6, echo request, seq 59776, length 64 16:57:34.471760 IP6 2001:648:ff00:12::1 > 2001:648:2530:1::1: ICMP6, destination unreachable, unreachable port[|icmp6] While this: mtr -6n --address 2001:648:ff00:12::2 ipv6.google.com Results in this: 17:12:57.535817 IP6 2001:648:ff00:12::2 > 2a00:1450:4001:c01::93: ICMP6, echo request, seq 59520, length 64 17:12:57.545450 IP6 2001:648:ff00:12::1 > 2001:648:ff00:12::2: ICMP6, time exceeded in-transit for 2a00:1450:4001:c01::93, length 112 17:12:57.636093 IP6 2001:648:ff00:12::2 > 2a00:1450:4001:c01::93: ICMP6, echo request, seq 59776, length 64 17:12:57.646476 IP6 2001:648:2ffc:1106::1 > 2001:648:ff00:12::2: ICMP6, time exceeded in-transit for 2a00:1450:4001:c01::93, length 112 This seems like an issue with an access list since the first hop (2001:648:ff00:12::1) replies differently in those two cases. My handle is SHU4-SIXXS.