It's a good idea to keep a different key for every host. That way, should one be compromised, you're not compromising your access to all your hosts. An easy way to do this is to configure your SSH to automatically look for the key based on the host you're connecting to.
Edit the file
~/.ssh/config and add this
Host * rule in. Whenever SSH connects to a host, it will now look for a corresponding key in
Host * IdentityFile ~/.ssh/keys/%[email protected]%h
Try it out by connecting to a host that you have a key for.
$ ssh [email protected] Hi rstacruz! You've successfully authenticated, but GitHub does not provide shell access. Connection to github.com closed.