I use a single private key to login to several Linux servers using PuTTY. When I need to login to a new machine, I first log in by password authentication and then add my public key to
~/.ssh/authorized_keys2 and use the private key thereafter.
But there's one machine to which I cannot login with my private key. I checked permissions for
.ssh directory and
authorized_keys2 file but they are the same as in machines where I can successfully log in.
What could be the problem here? Is it possible for an admin to disable private key based logins?