Hi, I have connectivity issues to https://fly.io and also my machines via IPv6 through my home internet connection, but it works fine on other networks. Connection to Fly also work fine via IPv4.
This happens only on IPv6 and only to Fly.io (and my fly hosted machines) on my home internet connection. I’ve reached out to my ISP and the only thing they’ve suggested so far is that there’s a block on the Fly.io side. I’m extremely doubtful of this considering that when i run traceroute6 fly.io it times out after the first hop outside my LAN.
But the avoidance of doubt, is this something that Fly does? Has anyone experienced similar issues?
I wouldn’t usually be asking this kind of question but Fly is the only host I’ve experienced this IPv6 issue on (so far that I can find!)
We do not block IP addresses / blocks unless there is a known attack going on (which currently there is none AFAIK). It would be nice if you can share traceroute, but at the same time if it is just 100% loss outside of your home LAN then it might not be super useful 
Can you also possibly share your source IP / AS number?
My ISP AS is AS13037. Here’s the traceroute:
traceroute6 to fly.io (2a09:8280:1::a:791) from <my-ipv6>, 64 hops max, 28 byte packets
1 <my-ipv6> 3.958 ms 2.497 ms 2.357 ms
2 lo0-0.bng5.thn-lon.zen.net.uk 26.213 ms 21.367 ms 14.292 ms
3 * * *
[followed by many lines of * * *]
I’d prefer not to share my IP here as it’s my home network, but happy to DM it. As you say though, it’s just getting dropped at the hop after my LAN so probably doesn’t really help.
I tried to explain to my ISP that it simply can’t be a block from Fly as the packets aren’t reaching them at all, your confirmation of that would help a bunch! Thanks!
It’s also possible that something BGP is going funky between us and them on v6, I wouldn’t be surprised if that is the case, though your ISP doesn’t seem to have a BGP looking glass either… If you can get through to somebody technical on their side, having them try to run a BGP route to us and see if they even have a route / what ASes are in the route could also help (if this is not something broken directly on their side).
Thanks for this, I’ll pass it on to them!