How to enable root user ssh login in Ubuntu 16.04, 17.04, 18.04 , 19.04
Remote login with root user is never recommended as If a user gets access on your system by root. The user can do anything in your system can delete any files. so that system can become unfunctional. So, root login is not recommended in live server. but for your local environment or for your knowledge purpose you can do this.
1) Install Openssh-server package.
sudo apt install openssh-server -y
2) Start and Enable the service.
sudo systemctl enable ssh
3) Now we need to make some changes it the configuration file of ssh. which is in "/etc/ssh/sshd_config" this file is the main configuration file for ssh.
Their is a parameter in this file "#PermitRootLogin" which is responsible for managing root login we need to uncomment this line and add "PermitRootLogin yes" or you can run the ffollowing command to do this process.
4) Now we need to restart the ssh service.
5) Now we can ssh to root user to take remote login.