Port 8443 (TCP) — HTTPS alternate

Alternate HTTPS port, often admin panels.

🔒 Runs locally — your input never leaves this browser tab

Restrict admin interfaces by IP.

Check if port 8443 is open

On the server, see what is listening:

sudo ss -tulpn | grep ':8443 '

From another machine, test reachability:

nc -zv your-server.example.com 8443

With UFW (Ubuntu/Debian):

sudo ufw deny 8443

With firewalld (RHEL/AlmaLinux/Rocky):

sudo firewall-cmd --permanent --remove-port=8443/tcp && sudo firewall-cmd --reload