Enabling and disabling root login over SSH

Linux systems have a root account that is enabled by default. Unauthorized users gaining root access to the system can be really dangerous.

We can disable or enable the root login for SSH as per our requirements to prevent the chances of an attacker getting access to the system.

Getting ready

We need two Linux systems to be used as server and client. On the server system, install the openssh-server package, as shown in the previous recipe.

How to do it...

First, we will see how to disable SSH root login and then we will also see how to enable it again:

1. First, open the main configuration file of SSH, /etc/ssh/sshd_config, in any editor:

sudo nano /etc/ssh/sshd_config

2. Now look for the line that reads as follows:

PermitRootLogin yes

3. Change the value yes to no. Then save and close the file:

PermitRootLogin no

4. Once done, restart the SSH daemon service using the following command:

5. Now let's try to log in as root. We should get an error:

"Permission Denied" 

This is...