[lloeki]

RuntimeMaxSec would have systemd kill a live forwarded connection though?

[xk3]

closing ssh doesn't close the ports if they are being used, at least with ControlMaster. You need to run something like this to force the ssh daemon to close the port

    ssh -O cancel -L 4102:localhost:4000 pc

but if ControlMaster is stuck maybe autossh is better in that case, or use this:

    Host *
        ServerAliveInterval 11