Software Requirements and Conventions Used
| Category | Requirements, Conventions or Software Version Used | 
|---|---|
| System | Installed or upgraded Ubuntu 20.04 Focal Fossa | 
| Software | SSH | 
| Other | Privileged access to your Linux system as root or via the sudocommand. | 
| Conventions | # – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudocommand$ – requires given linux commands to be executed as a regular non-privileged user | 
- Open the /etc/ssh/sshd_configfile with administrative privileges and change the following line:FROM: #PermitRootLogin prohibit-password TO: PermitRootLogin yes The quick way to do this job could be just to simply use the sedcommand as shown below:$ sudo sed -i 's/#PermitRootLogin prohibit-password/PermitRootLogin yes/' /etc/ssh/sshd_config 
- Restart SSH service:
$ sudo systemctl restart ssh 
- By default the root’s password is not set on Ubuntu 20.04 and the error message Permission denied, please try againwill appear when attempting to SSH login as a root user. From this reason we need to set root’s password. When prompted enter your current user password followed by new root password:$ sudo passwd [sudo] password for linuxconfig: Enter new UNIX password: Retype new UNIX password: passwd: password updated successfully 
