When using certificate authentication with ssh, the instructions I have found indicate you should create a key-pair as
id_rsa. The public key is then sent to the remote system to be added to
authorized_keys2 frequently in the case of OS/X). Obviously, the originating system needs access to its private key
I recently broke this by renaming the
id_rsa file and fixed it by restoring the file to its original name; so presumably, ssh uses the file
~/.ssh/id_rsa. Is this correct? Is it configurable? I had presumed that I would use different private keys for different remote systems, to limit the impact of a compromised private key; is this simply impractical, and it's better to just re-use a single private key?