Password Less Login SSH

1. Create private and public keys on source server.

    [root@source~]# ssh-keygen
       
        Enter file in which to save the key (/root/.ssh/id_rsa): /root/.ssh/mykey <ENTER>
        Created directory '/root/.ssh'
        Enter passphrase (empty for no passphrase): <ENTER>
        Enter same passphrase again: <ENTER>

2. Copy public key to remotehost.

    [root@source~]# ssh-copy-id -i /root/.ssh/mykey.pub root@192.168.0.100
    root@192.168.0.100's password: <PASSWORD FOR REMOTEHOST>

    This command will copy contents of 'mykey.pub' file and appends into file "/root/.ssh/authorized_keys" on remotehost 192.168.0.100. This command also creates structure "/root/.ssh/authorized_keys" if not exists on remote host.

3. Login to remotehost.
   
    [root@source~]# ssh root@192.168.0.100
    [root@destination~]#