Feature Request: Add IPv6 support

[nstetter]

Hey team,

A lot of us are stuck behind ISPs that use CGNAT or just flat-out block port forwarding. This means we can't be "connectable" on Soulseek, so no one can browse our files or download from us, which really limits our ability to share.

Adding full IPv6 support would fix this problem for good.

With IPv6, everyone gets their own unique public IP address. There's no more NAT, and no more need to mess with port forwarding. We'd just be connectable, straight up.

Why this would be great:

• Solves many connectivity problem: Anyone on CGNAT or with a fussy ISP could finally be connectable.

• Faster, more stable connections: Direct end-to-end connections are just better and have less latency than trying to punch through a NAT.

• A healthier network: More connectable users = more available files for everyone.

• Future-proof: More and more of the internet (especially mobile networks) is moving to IPv6.

This seems like the best long-term solution, since IPv4 and CGNAT issues are only going to get more common.

Thanks for considering it!

[slook]

Blocked because a server admin would have to add support for it first. However client-side IPv6 support is nevertheless planned for the sake of future-proofing regardless of if official support ever happens or not... See related soulfind-dev/soulfind#60 .

[mathiascode]

Note that users who have forwarded their ports can still establish an indirect connection with you, i.e. asking the Soulseek server to tell you to connect to their port instead, so your files aren't completely unreachable.

no more need to mess with port forwarding

It would still require IPv6 firewall pinholing, but my understanding is that the Port Control Protocol (PCP) was designed for this purpose (it's essentially the successor to UPnP and NAT-PMP). We could implement it once we have a plan for IPv6 support in the Soulseek server.

Note that it's not guaranteed that the Soulseek server will receive IPv6 support, but I'm hoping if we come up with an easy way to add it to the server and clients, there's a chance.