(pôrt nok´ing)
(n.) A method of establishing a connection to a secured
network or computer within a network that does not have an open
port. A
remote device sends a series of series of connection attempts, in the form of
packets, to the computer’s closed ports, and the attempts are silently ignored but logged by the
firewall. When the remote device has established the predetermined sequence of port connection attempts, a
daemon triggers a port to open, and the network connection is established. This security method is analogous to knowing a “secret knock,” and only people who know the proper knock sequence will be allowed access. An advantage of using a port knocking technique is that a malicious
hacker cannot detect if a device is listening for port knocks.
Other forms: port knock (n.), (v.)