An attacker engages in fingerprinting activity to determine the type or
						version of the operating system of the remote target. Any platform, device,
						or server that communicates over the network will conform to one or more
						protocols, commonly TCP/IP and related protocols. Fingerprinting remote
						operating systems involves taking an "active" or a "passive" approach.
						Active approaches to fingerprinting involve sending data packets that break
						the logical or semantic rules of a protocol and observing operating system
						response to artificial inputs. Passive approaches involve listening to the
						communication of one or more nodes and identifying the operating system or
						firmware of the devices involved based on the structure of their
						messages.