Tickets - Partial routing problems :: SixXS - IPv6 Deployment & Tunnel Broker

Ticket ID: SIXXS #14206377
Ticket Status: Resolved

PoP: ausyd01 - OCCAID Inc. (Sydney)

Partial routing problems

Shadow Hawkins on Thursday, 03 September 2015 03:03:54

I'm seeing "No route" problems when trying to talk to a subset of the IPv6ternet:

$ ping6 -n minotaur.hezmatt.org
PING minotaur.hezmatt.org(2a01:4f8:121:3431:e2e4:22bb:25f5:6cad) 56 data bytes
From 2001:4830:ac:1::1 icmp_seq=1 Destination unreachable: No route
From 2001:4830:ac:1::1 icmp_seq=2 Destination unreachable: No route

$ ping6 -n ismyipv6working.com
PING ismyipv6working.com(2001:7b8:3:1e::60) 56 data bytes
From 2001:4830:ac:1::1 icmp_seq=1 Destination unreachable: No route
From 2001:4830:ac:1::1 icmp_seq=2 Destination unreachable: No route

$ ping6 -n www.google.com
PING www.google.com(2404:6800:4006:800::2004) 56 data bytes
64 bytes from 2404:6800:4006:800::2004: icmp_seq=1 ttl=59 time=38.3 ms
64 bytes from 2404:6800:4006:800::2004: icmp_seq=2 ttl=59 time=16.1 ms

Traceroutes to "no route" destinations aren't particularly enlightening:

$ traceroute6 -n minotaur.hezmatt.org
traceroute to minotaur.hezmatt.org (2a01:4f8:121:3431:e2e4:22bb:25f5:6cad) from 2001:4830:1200:85::2, port 33434, from port 57856, 30 hops max, 60 bytes packets
 1  2001:4830:1200:85::1  20.888 ms  13.599 ms  16.537 ms 
 2  2001:4830:ac:1::2  13.667 ms  19.136 ms  14.685 ms 
 3  2001:4830:ac:1::1  52.972 ms  14.750 ms  50.203 ms 
 4  2001:4830:ac:1::1  14.771 ms !N  50.262 ms !N  13.432 ms !N

Traceroutes to working destination, for completeness:

$ traceroute6 www.google.com
traceroute to www.google.com (2404:6800:4006:800::2004) from 2001:4830:1200:85::2, port 33434, from port 57825, 30 hops max, 60 bytes packets
 1  2001:4830:1200:85::1 (2001:4830:1200:85::1)  31.204 ms  22.908 ms  17.782 ms 
 2  ausyd01.sixxs.net (2001:4830:ac:1::2)  22.979 ms  17.840 ms  17.833 ms 
 3  sixxs.sydn01.occaid.net (2001:4830:ac:1::1)  17.850 ms  17.880 ms  59.757 ms 
 4  15169.syd.equinix.com (2001:de8:6::1:5169:1)  17.886 ms  59.816 ms  88.881 ms 
 5  2001:4860::1:0:8604 (2001:4860::1:0:8604)  59.831 ms  95.989 ms  73.418 ms 
 6  2001:4860:0:1::1253 (2001:4860:0:1::1253)  96.054 ms  73.400 ms  13.743 ms 
 7  syd09s01-in-x04.1e100.net (2404:6800:4006:800::2004)  73.331 ms  13.669 ms  13.416 ms

My tunnel ID is T168205, and everything has been working very nicely since I set it up until this morning. Smells like someone's dropped a link somewhere and there isn't an alternate path found.

Partial routing problems Private

Shadow Hawkins on Thursday, 03 September 2015 03:58:47

Howdy, I've got some further data on this issue. (Possibly coincidentally) I restarted my tunnel (actually, I stopped it for a while, so I wouldn't get timeouts to inaccessible v6 sites, then started it again for some more testing) and since then, the behaviour has been different:

$ ping6 -n minotaur.hezmatt.org
PING minotaur.hezmatt.org(2a01:4f8:121:3431:e2e4:22bb:25f5:6cad) 56 data bytes
^C
--- minotaur.hezmatt.org ping statistics ---
4 packets transmitted, 0 received, 100% packet loss, time 2999ms

Note that, rather than getting "No route" messages, I'm now getting simple dropped packets. Progress? Perhaps. Traceroute now gets a few more hops out, too, before dropping on the floor:

$ traceroute6 -n minotaur.hezmatt.org
traceroute to minotaur.hezmatt.org (2a01:4f8:121:3431:e2e4:22bb:25f5:6cad) from 2001:4830:1200:85::2, port 33434, from port 51382, 30 hops max, 60 bytes packets
 1  2001:4830:1200:85::1  14.426 ms  17.184 ms  13.985 ms
 2  2001:4830:ac:1::2  19.346 ms  14.052 ms  14.876 ms
 3  2001:4830:ac:1::1  14.077 ms  14.956 ms  13.481 ms
 4  2001:4830:fd:644::1  17.558 ms  13.564 ms  14.953 ms
 5  2001:4830:fd:642::1  181.699 ms  183.003 ms  181.119 ms
 6  2001:4830:ff:1200::2  183.077 ms  181.191 ms  194.306 ms
 7  2001:504:13::210:85  183.769 ms  199.874 ms  181.076 ms
 8  * * *
 9  * * *
(etc etc etc)

What's really weird, though, is that pings from the machine I'm trying to ping (minotaur) back towards the tunnel are working almost all the way in:

root@minotaur ~ # ping6 -n 2001:4830:ac:1::1
PING 2001:4830:ac:1::1(2001:4830:ac:1::1) 56 data bytes
64 bytes from 2001:4830:ac:1::1: icmp_seq=1 ttl=51 time=396 ms
64 bytes from 2001:4830:ac:1::1: icmp_seq=2 ttl=51 time=324 ms
^C
--- 2001:4830:ac:1::1 ping statistics ---
3 packets transmitted, 2 received, 33% packet loss, time 1999ms
rtt min/avg/max/mdev = 324.797/360.512/396.227/35.715 ms
root@minotaur ~ # ping6 -n 2001:4830:ac:1::2
PING 2001:4830:ac:1::2(2001:4830:ac:1::2) 56 data bytes
64 bytes from 2001:4830:ac:1::2: icmp_seq=1 ttl=50 time=325 ms
64 bytes from 2001:4830:ac:1::2: icmp_seq=2 ttl=50 time=325 ms
^C
--- 2001:4830:ac:1::2 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1000ms
rtt min/avg/max/mdev = 325.042/325.095/325.148/0.053 ms
root@minotaur ~ # ping6 -n 2001:4830:1200:85::1
PING 2001:4830:1200:85::1(2001:4830:1200:85::1) 56 data bytes
From 2001:4830:fe:2003::1 icmp_seq=1 Time exceeded: Hop limit
From 2001:4830:fe:2003::1 icmp_seq=2 Time exceeded: Hop limit
From 2001:4830:fe:2003::1 icmp_seq=3 Time exceeded: Hop limit
From 2001:4830:fe:2003::1 icmp_seq=4 Time exceeded: Hop limit

As before, the tunnel is still at least partially up and working, because I can ping some IPv6 addresses just fine. However, the fact that I can get from the machine having problems to almost all the way to my tunnel before weirdness starts is perplexing.

State change: confirmed Locked