Nmap

Came across an article that relates to Nmap, the network scanning tool. If you haven't tried Nmap, get it and give it a whirl. Very useful and effective.

Nmap helps identify many of the pertinent details associated with a network or system, including open ports, exposed operating systems, exposed services, etc.

Searchsecurity has a "manual" that can walk you through the process of setting it up and running it.

Chalmer