IPv6 Broken?

Sometime after 01:00 this morning odd things are occurring with IPv6

Trying to connect to a number of networks via IPv6 appears to fail and the traceroute goes cold before it leaves Zen's network...

https://tools.keycdn.com/ipv6-ping

1 <1 ms <1 ms <1 ms <My local gateway>
2 38 ms 21 ms 27 ms lo0-0.bng4.thn-lon.zen.net.uk [2a02:8010::15b]
3 10 ms 9 ms 9 ms lag-14.p1.thn-lon.zen.net.uk [2a02:8010:0:700::4c]
4 * * * Request timed out.
5 * * * Request timed out.


Other routes appear normal (like bbc.co.uk) and I can reach other hosts via other networks without any issues.
No changes this end, and at that time of the morning looks rather like PEW.

Tracing route to bbc.co.uk [2a04:4e42::81]
over a maximum of 30 hops:

1 <1 ms <1 ms <1 ms <My local gateway>
2 39 ms 20 ms 18 ms lo0-0.bng4.thn-lon.zen.net.uk [2a02:8010::15b]
3 10 ms * 10 ms lag-14.p1.thn-lon.zen.net.uk [2a02:8010:0:700::4c]
4 87 ms 101 ms 10 ms 2001:7f8:4::d361:1
5 9 ms 9 ms 9 ms 2a04:4e42::81

Is anyone else experiencing similar issues?

I have not tried jumping gateways as yet and it doesn't appear I've be reconnected over night.

This is looking like a routing issue somewhere. Trace into Zen [2a02:8010::15b / lo0-0.bng4.thn-lon.zen.net.uk]

Frankfurt

Start: 2024-09-28T21:18:10+0000
Loss Snt Last Avg Best Wrst StDev
1.|-- fd42:10::1 0.0% 4 0.1 0.1 0.1 0.2 0.0
2.|-- 2001:2000:3080:11e5::1 75.0% 4 0.6 0.6 0.6 0.6 0.0
3.|-- 2001:2034:1:6b::1 0.0% 4 1.0 1.1 1.0 1.4 0.2
4.|-- 2001:2034:1:be::1 0.0% 4 8.9 8.8 8.6 8.9 0.1
5.|-- 2001:2034:1:7a::1 0.0% 4 15.7 15.7 15.7 15.7 0.0
6.|-- ??? 100.0 4 0.0 0.0 0.0 0.0 0.0

But works from

Amsterdam

Start: 2024-09-28T21:18:11+0000
Loss Snt Last Avg Best Wrst StDev
1.|-- 2a03:b0c0:2::15 0.0% 4 0.7 1.5 0.7 2.5 0.9
2.|-- 2a03:b0c0:fffd::1e 0.0% 4 2.3 1.2 0.6 2.3 0.7
3.|-- 2a03:b0c0:fffe::54 0.0% 4 1.0 2.4 1.0 3.8 1.4
4.|-- 2001:7f8:4:1::32ed:1 0.0% 4 12.4 12.9 11.0 16.3 2.3
5.|-- ??? 100.0 4 0.0 0.0 0.0 0.0 0.0
6.|-- 2a02:8010::15b 0.0% 4 13.1 16.8 13.1 26.1 6.2

Edited by IamQ (Sat 28-Sep-24 22:20:17)

Signed up to say I'm seeing similarly weird things. WireGuard tunnel over IPv6 to Germany dropped around the same time you report. Weirdly, I can reach Hetzner, a German hosting provider, but not Deutsche Telekom. Traceroute looks fine but no traffic passes, and ICMP ping doesn't work either which is bizarre.

Oh thanks for letting me know. I'll try and look more into it tomorrow and may drop support an email

It's one for Zen technical support: clearly they have a problem with their IPv6 transit, which they've not picked up by their own monitoring.

FWIW, it's worth bearing in mind that the BBC is not IPv6-enabled. "bbc.co.uk" has an IPv6 address, but when you connect to it with a web browser all it returns is a redirect to "www.bbc.co.uk", and that does *not* have an IPv6 address.

Has been reported to the 1st line support team and directly to the IPv6 team

I'm not seeing anything where I cannot outright connect over ipv6. But, definitely for the last few days, some (maybe all, not sure) sites that are ipv6 enabled seem noticeably slower. If I set them to use ipv4 they are fine.

The plugin "IPvFoo" for Chrome browser (I don't know if it's available for others) gives a very useful indication of whether IPv4 of IPv6 is being used for the man page, and for any assets referenced within the page.

In reply to a post by candlerb:

The plugin "IPvFoo" for Chrome browser (I don't know if it's available for others) gives a very useful indication of whether IPv4 of IPv6 is being used for the man page, and for any assets referenced within the page.

Oh, I know that I can check. But I've only spotted it happening on two sites so far and I've not been actively checking otherwise.

I notice refreshing on here is sometimes delayed longer than usual, and ipv6 is used here. So maybe 3 sites.

It does seem intermittent too.

Edit: Right now it's back to super fast over ipv6 on all the sites I was seeing slowness.

Edited by agent_r00t (Wed 02-Oct-24 13:40:33)

My ipv6 only SIP registration has been failing (sip6.voipcheap.com). Zen support have not got back to me yet .
It's working fine on my FIL's community fibre connection, so I know it's Zen IPV6 at fault

And has been escalated to the infrastructure team & Zen have confirmed many more reports of problems have started coming in relating to v6 issues.

Edited by IamQ (Thu 03-Oct-24 17:16:40)