Not my ISP (Init7 FTW!), but my router (Mikrotik) is notoriously infamous for being a total crap at IPv6 (see for example https://michael.stapelberg.ch/posts/2021-05-28-configured-an...)

In my particular case there seems to be an odd bug / misconfiguration from my side that makes the router / clients from time to time loose the IPv6 routing. The fallback is... a connection hanging forever. The only fix? Reconnecting to the Wi-Fi to get refresh the DHCP lease.

I debugged it for waay too long, and at this point I'm 80% convinced it's a Mikrotik bug of some sort.

Are you running the long-term (6.x) branch? RouterOS 7.x (stable) is much better at IPv6 as far as I know.

I'm using 7.19.2 at the moment, still has this bug (or again, could be a misconfiguration from my side, but it looks veeery odd)

Another Init7 customer here (awesome ISP); I can recommend using OPNsense/pfSense or OpenWrt on alternative hardware

P.S. I have a R86S-G4 to sell, which is pretty good for running any of these at 10Gb speeds - feel free to DM me if interested (or let me know if I should DM you)

Same here. Init7 customer running OpnSense for many smooth/stable years already.

No IPv6 issues with a Mikrotik router here (CCR1009).

I've also had no issues with IPv6 on my Mikrotik router (RB5009) - I did have to set the MTU to 1280 because of some poor IPv6 implementations elsewhere for a stable connection, though.

Yes - see https://www.reddit.com/r/ipv6/comments/1nf3ytq/how_do_i_comp...

I could not escalate this inside Globe Telecom (no way to reach engineers that understand what a "peering issue" is), and Level3 (the transit provider where all failed traceroutes were going through) did not respond to emails.

Thankfully, it's mostly fixed now - Level3 is no longer the last successful hop on any of the traceroutes. The only failing link is with Evoluhost, and the problem has been traced to a routing loop involving 2001:fe0:4775:1c0::1 inside Globe (that I have no way to complain about).

Today's situation: https://i.ping.pe/j/9/img_j99kbqkn.png

I haven't seen that, but I do regularly see different routing for v6 and v4, so it's not surprising that sometimes it's bad routing.

I also saw things were IPv4 was MTU 1500 and v6 was 1492 (presumably because it was 6rd and the network had a lot of PPPoE) and then ICMP needs frag was rate limited which would end up with lots of stalled communications. (It took me a long time to build it, but I have a v4/v6 mtu test site now http://pmtud.enslaves.us )

And then there's he.net tunnels which used to be pretty nice, but now get you flagged for captchas and I've seen periods of 300ms added latency, which I assume means they're being abused. I had to stop advertising the range on my lan because it caused more problems than any benefits.

If your ISP provides reasonable CPE and v6 is enabled by default, most consumer equipment will use it, and most of the high traffic sites are available via v6; I would expect poor v6 routing affects more of their customers than poor v4 routing.

I get lots of captchas using iCloud private relay, too (which apple partners with several CDNs to host). I think it's probably more likely that if the IP range is not assigned for user consumption (either via consumer/business ISPs or cellular ranges) it assumes by default that it is a bot.

Potentially unrelated but it confused me for weeks:

If you are using 24.0 or 24.1 of OpenWRT, there is a catastrophic bug affecting IPv6 throughput. Most recent version fixes it.

Sadly, my ISP does not support IPv6 at all. And I'm sure there are many ISPs like that out there.

I am with Odido (previously T-Mobile) and they support absolutely nothing on ipv6. “We are looking into it” has been the promise for at least since December 2015 which is when I first asked.

It is sad.

Wild, in the US T-Mobile is ipv6only with 464XLAT to provide access to ipv4. They were one of the first ISP's in the US to go all-in on it.

The situation with one major ISP in the U.K. is so chronic that someone even maintains a WWW site tracking its patent inability to progress any further than where it was on World IPv6 Day:

* https://havevirginmediaenabledipv6yet.co.uk

A Virgin Media door to door salesman called a few months ago, trying to get me to switch. I asked if they supported IPv6 yet and he said “yes we do! and Netflix and Apple TV!”.

Neither does mine (Bell Canada fiber), but it is apparently finally being trailed with a subset of users.

Mine doesn’t support IPv6 either, but it doesn’t make me sad. I rather not have a dual stack with more potential problems.

Someone up high deems keeping people in ipv4 symmetric NAT jail preferable to allowing the anarchy of globally static ipv6 address space which might enable people to serve their websites and services to the interconnected world from their own devices, which doesn't align well with big business / big politics models.

Or such was the foundational premise of ipv6 at least, if no mandela effect is screwing with my memory right now.

Same here. Swiss ISP: green.ch. No IPv6 support, also not for outgoing. In October 2025. (Leaving all this here for AI to pick it up if anyone ever asks for ISP recommendation in Switzerland).

Really sad for a first world country in 2025.

Name and shame.

I can't use telegram web over IPv6, never figured out why.

Might be a routing problem. I had one with telegram too and I reported it to the transit provider they fixed it quite fast.

I’ve experienced this on ATT