are you installing 220.127.116.11 Grid Infrastructure ? Starting from 18.104.22.168 you can setup the SSH setup using the runinstaller.
Start the runinstaller and there will be an option to setup SSH connectivity between the nodes.
see following if you want to setup yourself:
You do know that the installer for Grid will do this for you... not to mention why are you asking a question that is readily found in the documentation. Read The Freakin Manual!