I have a WiFi router, connected by Ethernet cable to my Ubuntu desktop and Android mobile. I have
sshd set up.
The telephone-line-in cable to the router was cut. But both devices were still connected to it, but unable to access the Internet.
So, just to test, I tried to establish an SSH connection from my mobile to the desktop (using the ConnectBot Android app). To my utter astonishment, I got a successful SSH session.
Why were the two devices able to connect through SSH?