Many times we need to use different keys to connect to different hosts. This can be very easily done in Mac OS X or Linux.
For instance if we have two private keys generated: id_rsa, id_rsa2.
We just need to edit the file “~/.ssh/config” or create it if it doesn’t exist.
vi ~/.ssh/config
Then add the hosts and authentication method:
Host www.EXAMPLE1.COM Hostname www.EXAMPLE1.COM User YOURUSERNAME PreferredAuthentications publickey IdentityFile ~/.ssh/id_rsa Host www.EXAMPLE2.COM Hostname www.EXAMPLE2.COM User YOURUSERNAME PreferredAuthentications publickey IdentityFile ~/.ssh/id_rsa2