SSH Hardening

Secure SSH access.

Change default port in /etc/ssh/sshd_config:

Port 2222
PermitRootLogin no
PasswordAuthentication no

Restart SSH:

sudo systemctl restart sshd

Key-based authentication:

ssh-keygen -t ed25519 -C 'email@example.com'
ssh-copy-id -i ~/.ssh/id_ed25519.pub user@server