Port Knocking Explained: The Secret Handshake for Secure Server Access
https://knowledge.businesscompassllc.com/port-knocking-explained-the-secret-handshake-for-secure-server-access/
Ever considered how you hide your house key? Under a rock, inside a fake sprinkler head, or using that magnetic box stuck to your car’s undercarriage? Now imagine if your server’s open ports are those house keys – except they’re visible to literally anyone walking by.