fast lan to wan transition

[TheDreadPirate]

There is a way to do this, but not in Jellyfin.

Many routers support a functionality call "NAT loopback". When the router resolves your domain and sees that it the result is itself, it will keep traffic local instead of routing it to the internet and back.

The other way to achieve this, which is what I do, is setup a custom DNS entry in my router so that all local clients will get the local IP whenever they attempt to resolve my domain. When my phone leaves my home network it will instead get the public IP. This method also has the benefit of not needing an Internet connection.