Enable Root Login over SSH on Linux

By default SSH comes configured in a way that disables root user logins

Note: On Ubuntu, by default installation comes with unset root password, To set root password, please read this article.

Enable Root Login over SSH

1. To disable root login, edit file /etc/ssh/sshd_config:

[admin@serverhow.com ~] sudo vi /etc/ssh/sshd_config

2. Add a line in the Authentication section of the file that says PermitRootLogin yes. This line may already exist and be commented out with a “#”. In this case, remove the “#”.

PermitRootLogin yes

Save the updated of config file

3. Restart the SSH service

# Restart ssh service on Redhat/CentOS
[admin@serverhow.com ~]  sudo systemctl restart sshd

# Restart ssh service on Ubuntu/Debian/Linuxmint
[admin@serverhow.com ~] sudo  /etc/init.d/ssh restart

You can now connect to the server as root over SSH.

Limit SSH User Logins

Edit file /etc/ssh/sshd_config, add an AllowUsers line at the bottom of the file with a space separated by list of usernames.

AllowUsers <user>

Replace <user> with your user. After restart ssh service