a software program used to send a series of messages to each port on a computer, one at a time, to see which ports are open While used by network administrators to test system security, port scanning gives a hacker an idea where to probe for weaknesses to access the system
Data sent by the cracker over the Internet to locate a PC or network and determine whether it has open ports that will accept a connection
A port scan is a series of messages sent by someone attempting to break into a computer to learn which computer network services, each associated with a "well-known" port number, the computer provides Port scanning, a favorite approach of computer cracker, gives the assailant an idea where to probe for weaknesses Essentially, a port scan consists of sending a message to each port, one at a time The kind of response received indicates whether the port is used and can therefore be probed for weakness
An automated scan of a range of TCP or UDP port numbers on a host to detect listening services See Hacking Exposed chapter 2