Or you could add the following to your ~/.ssh/config instead: Host protected_machine other_protected_machine ProxyCommand /usr/bin/ssh gateway.example.

Or you could add the following to your ~/.ssh/config instead: Host protected_machine other_protected_machine ProxyCommand /usr/bin/ssh gateway.example.com /bin/nc -w 3700 %h %p (Assumes you have /bin/nc installed on your gateway.)