IPv6 routing issues from ietf-hotel

[lars@…]

Hi,

there seem to be some intermittent IPv6 routing issues, at least from the ietf-hotel network; v4 seems fine:

[lars@dhcp-89f5:/Users/lars] $ ping6 eggert.org
PING6(56=40+8+8 bytes) 2001:67c:370:136:4c92:a8b8:9b0e:2303 --> 2001:a60:1595:7d01:211:32ff:fe22:186f
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=0 hlim=239 time=242.752 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=1 hlim=239 time=235.921 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=2 hlim=239 time=231.295 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=3 hlim=239 time=237.018 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=4 hlim=239 time=231.539 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=5 hlim=239 time=246.774 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=6 hlim=239 time=232.966 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=7 hlim=239 time=230.949 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=8 hlim=239 time=230.532 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=9 hlim=239 time=238.935 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=10 hlim=239 time=230.351 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=11 hlim=239 time=1004.302 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=12 hlim=239 time=1003.870 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=13 hlim=239 time=235.288 ms
ping6: sendmsg: No route to host
ping6: wrote eggert.org 16 chars, ret=-1
ping6: sendmsg: No route to host
ping6: wrote eggert.org 16 chars, ret=-1
ping6: sendmsg: No route to host
ping6: wrote eggert.org 16 chars, ret=-1
ping6: sendmsg: No route to host
ping6: wrote eggert.org 16 chars, ret=-1
ping6: sendmsg: No route to host
ping6: wrote eggert.org 16 chars, ret=-1
ping6: sendmsg: No route to host
ping6: wrote eggert.org 16 chars, ret=-1
ping6: sendmsg: No route to host
ping6: wrote eggert.org 16 chars, ret=-1
ping6: sendmsg: No route to host
ping6: wrote eggert.org 16 chars, ret=-1
ping6: sendmsg: No route to host
ping6: wrote eggert.org 16 chars, ret=-1
ping6: sendmsg: No route to host
ping6: wrote eggert.org 16 chars, ret=-1
ping6: sendmsg: No route to host
ping6: wrote eggert.org 16 chars, ret=-1
ping6: sendmsg: No route to host
ping6: wrote eggert.org 16 chars, ret=-1
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=26 hlim=239 time=240.903 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=27 hlim=239 time=233.495 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=28 hlim=239 time=233.678 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=29 hlim=239 time=232.859 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=30 hlim=239 time=229.608 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=31 hlim=239 time=230.025 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=32 hlim=239 time=230.057 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=33 hlim=239 time=237.716 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=34 hlim=239 time=230.032 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=35 hlim=239 time=233.586 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=36 hlim=239 time=229.888 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=37 hlim=239 time=229.667 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=38 hlim=239 time=230.851 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=39 hlim=239 time=233.029 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=40 hlim=239 time=233.065 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=41 hlim=239 time=328.014 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=42 hlim=239 time=238.850 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=43 hlim=239 time=231.663 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=45 hlim=239 time=235.334 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=46 hlim=239 time=229.403 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=47 hlim=239 time=1005.209 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=48 hlim=239 time=635.769 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=49 hlim=239 time=1004.493 ms
16 bytes from 2001:a60:1595:7d01:211:32ff:fe22:186f, icmp_seq=50 hlim=239 time=234.862 ms
^C
--- eggert.org ping6 statistics ---
52 packets transmitted, 38 packets received, 26.9% packet loss
round-trip min/avg/max/std-dev = 229.403/328.014/1005.209/241.128 ms

Lars

[cdoyle@…]

I'm looking into this now. It looks like we have a packet-loss issue 3-hops outside of our network in the TWC AS. I will update the ticket as I gather more information.

C

[cdoyle@…]

Lars,

It looks like packets routing through upstream 2605:e00::/32 routers are experiencing about 8-15% packet loss. I'm chasing it down now.

[jim@…]

Lars,

You may be seeing either of two issues we're tracking. First, we have a known issue with the ietf-hotel ssid that incoming scans are causing lots of ARP traffic, which is kicking off storm control on the hotel's Access Points. The second is a particular link within TWC that's experiencing 15+% v6 loss. We're working with TWC on the loss issue, and are trying to get creative on how to reduce the ARP load on the ietf-hotel net. If you were to plug into the wired connection in your room, it would eliminate the ietf-hotel issue.

Sorry for the annoyance! We'll update the ticket as we learn more...

• Jim

[jim@…]

Lars,

Could you test again? We've substantially improved the ARP issue (and hence, the multicast/broadcast issue) on the ietf-hotel net. We also believe we've resolved the ipv6 loss issue within TWC.

Many thanks!

• Jim

[cdoyle@…]

Replying to jim@…:

Lars,

Could you test again? We've substantially improved the ARP issue (and hence, the multicast/broadcast issue) on the ietf-hotel net. We also believe we've resolved the ipv6 loss issue within TWC.

Many thanks!

• Jim

Turns out that the ticketing system is handling replies different now then it was before. So sorry for the radio silence. Please click the link to check the ticket directly to see the current notes.

[Clemens Schrimpe]

This should be resolved now. Please retest.

[jim@…]

Lars,

We strongly believe this is resolved, so I'm going to resolve the ticket. If you find that not to be the case, please let us know and we'll be happy to work to address anything outstanding.

• JIm

[Rick Alfvin]

Milestone renamed