SSH fails due to RSA Key
I formatted and reinstalled Fedora Core 4 on my file server. Now when I try to SSH it from my workstation it says it can't do it due to RSA ket mismatch or something like that and that I need to change the /home/"usr"/.ssh/"key" or the like. I am at work and can't remember the exact error so apologies if it isn't exact. Is there a way to reset or fix this?
This is because your workstation remembers the old key and compares it with the one from the server everytime it connects (this is a security feature); when it's different, that could be a bad thing. Now that you reinstalled Fedora Core on your server, the new installation of SSH probably generated a new key. So you need to go into your workstation's ~/.ssh/known_hosts and delete the line corresponding to your server and its old key; that way it will remember the new one the next time.
Yeah, spoon is right, the files you need to look at on the server are ~/.ssh/known_hosts and ~/.ssh/authorised_keys.
You probably need to generate new keys and add them to the authorised_keys file.
When you've done editing them, dont forget to check the permissions...