[calamari4065]

And what do you do when your ssh server stops working, or there's a hardware fault, a network fault, a failed OS upgrade?

[filoleg]

Idk about all machines ever, but I remember being able to access ssh over a serial port.

Though in that specific case for me, it was more of a necessity rather than just a quirky way of using ssh (due to the “machine” just being a dev board with a UART ESP32).

[calamari4065]

To access the serial port remotely you need to add hardware to bridge it to the network. Or you go up to the machine and plug in another computer with a keyboard and monitor to access it directly.