Proper IPv6 support

[Jamesits]

Verification needed:

DST Server

• IPv6 Support
• Listen on IPv6 address
• IPv6 only environment

DST Client

• IPv6 Support
• IPv6 only environment

Klei auth server

• IPv6 Support
• IPv6 only environment

Docker

• Enable IPv6
  (Note: enable IPv6 from Docker daemon directly will cause the daemon to fail. Additional undocumented steps needed.)
• Auto NAT (like IPv4)

[serpi90]

You could avoid docker networking and use network_mode: "host" (docker-compose)
That way you skip network virtualization and use the underlying host's network.
It's not valid for all use cases, but may solve problems with ipv6

[Jamesits]

@serpi90 Yes I know this. Still, there are cases where custom networking is unfeasible (e.g. in a swarm or k8s cluster).

I haven't looked into it for years because IPv6 support for Docker has never become better during these years. They are still crappy, the docs are still not working and when you enable it everything starts to fail.

[Jamesits]

Waiting for moby/moby#41622