Sometimes for any reason you want to enable root ssh using any SSH Client such as putty and only the administrator can login to do this follow the below steps :-
vi /etc/ssh/sshd_config
search for line as follow :-
PermitRootLogin yes and change it to –> PermitRootLogin no
Search for the following lines as well :-
DenyUsers root user2 user3
Remove the root from Deny User
DenyUsers user2 user3
/etc/init.d/sshd restart
Stopping sshd: [ OK ]
Starting sshd: [ OK ]
If you want to disable the SSH login for root just keep everything like the above.
