Arunjay__

You were right above. I just tested it. Mosh sets the -S flag as none by default on ssh and disables controlmaster. If you use --experimental-remote-ip=remote u can ask the server for an address and the controlmaster config will work.

If the host is behind a NAT then use =local instead of =remote.

im also currently making it so mosh-rs prints a hint when it sees a ControlMaster socket the default mode is about to bypass. should be out soon.

Its a file by file rewrite. Please let me know if you find any file which is not.

You can get most of what you want today without a protocol change. mosh only uses ssh for the initial hop, and it just runs whatever ssh is on your PATH, so your ~/.ssh/config applies. Put a ControlMaster/ControlPersist entry in there and only the first tab actually authenticates. Every tab after that reuses the socket, and the "ssh host mosh-server new" step is quick. Each tab still ends up with its own UDP connection, but that's one tiny server process and one key per tab, not a new login.

Sharing one SSP connection across several terminals is a big protocol change, and I'm deliberately keeping mosh-rs wire-compatible with upstream, so I don't want to go off on my own there. For "lots of tabs, one connection" the thing that works well is one mosh session into tmux, and tmux control mode (tmux -CC) if your terminal supports it. That gives you native tabs over a single mosh link, which is about as close to ControlMaster as you can get with mosh's design.