Hi, Any BT Network engineers who might be able to have a look in to something for me?
The router at 2a00:2302::1102:100:37 appears to be generating ICMPv6 Destination Unreachable messages when it should be generating TLL Expired. root@onsite:~# traceroute6 -I google.com traceroute to google.com (2a00:1450:4009:80b::200e), 30 hops max, 80 byte packets 1 broadband.bt.com (2a00:23c4:3e5d:fb00::1) 0.543 ms 0.698 ms 0.858 ms 2 * * * 3 2a00:2302::1102:100:36 (2a00:2302::1102:100:36) 9.510 ms 9.522 ms 9.539 ms 4 2a00:2302::1102:100:37 (2a00:2302::1102:100:37) 14.093 ms !X 14.756 ms !X 15.366 ms !X As you can see, Destination Unreachable - however: root@onsite:~# ip6tables -t filter -A INPUT -s 2a00:2302::1102:100:37 -j DROP root@onsite:~# traceroute6 -I google.com traceroute to google.com (2a00:1450:4009:80b::200e), 30 hops max, 80 byte packets 1 broadband.bt.com (2a00:23c4:3e5d:fb00::1) 0.542 ms 0.710 ms 0.894 ms 2 * * * 3 * * * 4 * * * 5 2a00:2380:3014:8000::2 (2a00:2380:3014:8000::2) 10.711 ms 10.724 ms 10.776 ms 6 2a00:2380:14::5 (2a00:2380:14::5) 10.824 ms 8.654 ms 8.699 ms 7 2a00:2380:14::f (2a00:2380:14::f) 11.519 ms 10.855 ms 10.846 ms 8 2a00:2380:5::1e3 (2a00:2380:5::1e3) 11.175 ms 11.162 ms 10.837 ms 9 2a00:2380:2001:1000::3 (2a00:2380:2001:1000::3) 11.129 ms 10.996 ms 10.815 ms 10 2001:4860:0:1::1829 (2001:4860:0:1::1829) 10.099 ms 9.773 ms 9.915 ms 11 2001:4860:0:1::156d (2001:4860:0:1::156d) 11.365 ms 11.352 ms 11.344 ms 12 lhr35s04-in-x0e.1e100.net (2a00:1450:4009:80b::200e) 9.691 ms 9.872 ms 9.749 ms If I ignore the erronious packet from hop 4 I am able to reach the destination just fine. Just to clarify this does not appear to impact normal traffic and only causes problems for traceroute, but I can't live without my traceroute... Thanks - Mike Jones
