" Network administrators have many tasks, and auditing the
network is at the top of the heap. This isn't a problem if you have
a small network. But what happens when that network outgrows your
ability to simply walk around and manually make note of what is
up/down, what OS a device is running, or what ports are open? When
this happens you need to make use of one of the de facto standard
open source network auditing tools — Zenmap.
"The Zenmap tool is actually a graphical front end for the very
popular Nmap command line tool. Nmap is an open source tool for
network security and auditing. Although Nmap is incredibly
powerful, when working with larger networks most administrators do
not want to work with command line only tools. And besides, as they
say "A picture is worth a thousand words". In this case that is
very much true because Zenmap will give you an interactive
graphical map of your network."