SSH (Secure Shell) is a protocol for creating a secure connection between two computers.The secure SSH connection provides authentication and encryption. SSH also provides compression and is most common way for users and root to get connect to the server (Linux), the main reson behind blocking the root user is to allow the admin to login into the box with the default normal user and do the the administrator task using sudo, no direct root login.

1. vi /etc/ssh/sshd_config
3. Locate the parameter — PermitRootLogin yes
4. Change this to PermitRootLogin no
5. Save and exit
6. Restart your sshd by type sudo /etc/init.d/ssh restart