Disable non-root SSH access
Best practice is to:
- Disallow root login
- Block password-based login
- Allow only SSH-based login
Do this by editing /etc/ssh/sshd_config
:
PasswordAuthentication no
ChallengeResponseAuthentication no
Then restart the SSH service:
sudo systemctl restart sshd
(Assumes you have already set-up SSH-based login for a non-root user!)