IPv6 UDP support

Hey all!

From my searching it seems a tradition to ask each new year how IPv6 UDP support is coming along!

I am exploring ways to host a DNS service and having IPv6 is (these days) pretty wanted for that kind of thing.

I can see and read that basically the only use case for this is DNS (mostly) and it’s probably not high on the list for Fly, but after a few years of on-and-off news I hoped it would be along by now :slight_smile:

Hope we can get another update on how the priorities are on this!



Another use case is QUIC related apps.


QUIC won’t be easy. You’d need a QUIC-aware load balancer / reverse proxy as the protocol supports connection migrations across servers and client IPs.

Also curious about this.

I’m hoping to establish stateful WebRTC connections with individual Machines, and I’ve hit a bit of a roadblock. Without UDP over IPv6, I’d have to allocate a dedicated IPv4 address per Machine (i.e. possibly spin up a new app per each Machine), which rapidly becomes expensive at $2/mo for each IP.

Or perhaps there’s a better way to accomplish this?

I’m also looking at Fly.io’s suitability for hosting a DNS service. In my case IPv4 is more of an impediment than a benefit and ideally I’d have a unique IPv6 address per user. Hopefully this is something Fly.io can fulfil at some point in the near future.


I also want http3 btw …

Until then I have to use Cloudflare

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wait Public Network Services · Fly Docs seems to indicate we can control anycast for UDP, sou you could run your own DNS anycast and other things like http3 / quic ?

@gedw99 No, UDP doesn’t work on IPv6 on Fly (which is what this thread is about … I guess this update is another annual-ish request for an update :slight_smile: )