hostname routing

[snek]

Hi,

I'm trying to figure out if there's a good way to expose my git server's ssh to the world without having to give it a dedicated IP (I do like the idea of using dedicated IPv6 addresses for different services, but I do still need to access my stuff on legacy IPv4 networks...)

In the HTTP world we use features like the Host header and TLS SNI/ECH to figure out how to route a request instead of relying on dedicated IPs. I searched through RFCs, docs, and mailing list archives a bit for similar topics and didn't really find anything about such functionality in the SSH protocol.

I'm very curious for opinions on this, alternative approaches, issues, etc. The immediate thing that jumps out to me is whether a theoretical "ssh reverse proxy" implementing this theoretical protocol extension would actually be possible within the existing encryption model, especially if the hostname extension was exchanged after an encrypted channel was established, but I'm hoping that given the existence of ProxyJump, something like what I'm imagining is possible.

Thanks,
snek