IPv6 enet support

[fcxSanya]

IPv6 adoption is rising, some ISPs already provide IPv6 addresses only, so we eventually will have to support it in the network layer.

pyrogenesis uses ​ENet which currently isn't IPv6 compatible, the best place to track ENet IPv6 status is probably this pull request: ​https://github.com/lsalzman/enet/pull/21.

[fcxSanya]

IPv6 support topic was raised on IRC a number of times, so I decided it would be useful to gather all the information in a ticket, so it would be possible to easily find the current status and track possible updates

[echotangoecho]

Also take note of this issue from another project wanting to get ipv6 support using enet: ​https://github.com/godotengine/godot/issues/6992. We should try to fix this before next release as this is important to have (not having it denies an increasing number of people the ability to play multiplayer).

[elexis]

I didn't come across a single bug report yet about missing ipv6.

Currently we support enet 1.3 or older, (see wiki:BuildInstructions) and even the most recent enet version doesn't include ipv6. The latest commit in ​https://github.com/lsalzman/enet was in june, while the link you provided shows pull requests from october. So it seems out of reach for now.

Also this didn't discuss lobby / XMPP support yet, which would be mandatory for allowing seamless IPv6 support.

[elexis]

I didn't come across a single bug report yet about missing ipv6.

Recent ejabberd uses IPv6 by default and needs to be configured to only listen on IPv4. (Otherwise hosting will work with STUN enabled but not without it.)

There are different pull requests for enet ipv6 support and we must consider patching enet locally if not getting it merged upstream.