The following steps can be used to ssh from one system to another without specifying a password.
Step 1. On the client run the following commands:
ssh-keygen -t rsa
The output will look like this:
root@client:~# ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is: