Consider the following scenario:
I have a Debian-ssh-server setup and exposed it to the internet for some time for testing. Also I have an account which is basically configured as root in the
sudoers file (I know this is poorly mis-configured!) and of course no root login is permitted. The authentication is password and not key based.
What happened is the following, I have set up the server from my own laptop and I could login to this account from anywhere, at home of course and even from other networks. But as I tried to login from another machine I got the 'access denied' message.
What grinds my gears is why could I login from my home machine, the access should have been denied either, shouldn't it?