[ Thanks to LinuxLinks for this link.
]
“A port scanner is a utility which probes a server or
host to verify if the virtual ports of a system are open or closed.
Ports allow different applications on the same computer to share
network resources simultaneously.“Port scanning has many legitimate uses such as network
inventory and the verification of the security of a network. Port
scanners therefore represent an important tool for users and system
administrators to verify the security policies of their computers
and network.“Linux has a good range of port scanners that help
administrators identify and rectify weaknesses in a system. To
provide an insight into the software that is available, we have
compiled a list of 5 of our favorite port scanners. Hopefully,
there will be something of interest here for administrators or
users that want to scan computers and services that are running on
a network. We give our strongest recommendation to Nmap, an
indispensable utility to gather information about remote
computers.”