I’d like to host lemmy on my LAN and I’d be the only user, no registration open. I would subscribe to communities on other instances and my instance would get the posts and comments. would that work? I don’t need it to be accessible from the internet.
My understanding is that ActivityPub is designed with the expectation that servers can look one another’s names up in DNS and initiate TCP connections to one another.
So even if all of your end-users are on your LAN, your instance still needs to have a public address that’s discoverable in DNS, etc.
You might be able to rig this up via tunneling, but you’d still need a public address on the other end of the tunnel.