SSH access to root user opens vulnerability door to the system that can be exploited by hacker. You should login as non root user and use su command to gain root privileges.
In order to block SSH access to root you need to complete the following steps.
Find this section in the file, containing the line with “PermitRootLogin” in it.
Remove the # sign and change the permission to no. Your line should look similar to the following.
After making change save the file
Now restart the sshd service:
You did it. Now nobody can brute force your root login, at least.