Port 22 (TCP) — SSH / SFTP

Secure Shell remote login, SFTP and SCP.

🔒 Runs locally — your input never leaves this browser tab

Constant brute-force target. Disable password login, use keys, restrict by IP or put it behind a VPN such as WireGuard.

Check if port 22 is open

On the server, see what is listening:

sudo ss -tulpn | grep ':22 '

From another machine, test reachability:

nc -zv your-server.example.com 22

With UFW (Ubuntu/Debian):

sudo ufw deny 22

With firewalld (RHEL/AlmaLinux/Rocky):

sudo firewall-cmd --permanent --remove-port=22/tcp && sudo firewall-cmd --reload