In computer networking, port knocking is a method of externally opening ports on a firewall by generating a connection attempt on a set of prespecified closed ports. Once a correct sequence of connection attempts is received...

Port knocking is a stealth method to externally open ports that, by default, the firewall keeps closed. It works by requiring connection attempts to a series of predefined closed ports. With a simple port knocking method, when the correct sequence of port "knocks" (connection attempts) is received...

Port knocking is a simple method to grant remote access without leaving a port constantly open. Port knocking improves security, because it can remove the need to leave ports open.

This article describes how to use a feature called Port Knocking, to improve the security of your MikroTik device, and minimize a risk of hacking attempts over such protocols like SSH, Telnet, Winbox, etc.

Port knocking is "a method of externally opening ports on a firewall by generating a connection attempt on a set of prespecified closed ports...

This technology (Port Knocking) has a very important and interesting feature. Port Knocking technology is performed through a sequence of attempts to connect to closed ports.

Port knocking is a method of protecting your services behind a firewall until connection attempts are made to a specific sequence of ports in a certain amount of time.

A Port-Knocking System. Used along other security systems, improves security. A Simple Port Knocker. Given a host, looks up its port sequence and knocks on it.