I have a small home network. One desktop runs 12.04, the other and my laptop run 16.04.
I can connect to the 12.04 machine using SSH from both 16.04 machines, and also from an Android tablet (using VxConnectBot).
However authentication fails when trying to connect from the 12.04 machine to any of the other units.
12.04 is running SSH 5.9; 16.04 SSH 7.2. Is this the problem? Is it possible to upgrade SSH 5.9 to SSH 7.2 under 12.04?