Using a Ubuntu 10.04 desktop...
I just rebuilt another computer (Ubuntu 10.04-Server) and when I attempt to ssh to the box I of course have the ssh key from the old install. I get the message
Add correct host key in /home/ken/.ssh/known_hosts to get rid of this message.
Offending key in /home/ken/.ssh/known_hosts:3
So how do I determine which key is hosts:3? It is not the third key in the known_hosts file - I deleted that one and got the same error.
As I only have 4 other computers on my network I generally just delete all entries from known_hosts when I reinstall the OS on one of the others. It is about time I learn how to do it correctly