Nmap Network Scanning is the official guide to the Nmap Security Scanner, a free and open source utility used by millions of people for network discovery, administration, and security auditing. From explaining port scanning basics for novices to detailing low-level packet crafting methods used by advanced hackers, this book by Nmap's original author suits all levels of security and networking professionals. The reference guide documents every Nmap feature and option, while the remainder demonstrates how to apply them to quickly solve real-world tasks. Examples and diagrams show actual communication on the wire. Topics include subverting firewalls and intrusion detection systems, optimizing Nmap performance, and automating common networking tasks with the Nmap Scripting Engine.
The Insecure.org developers have announced the release of version 5.0 of Nmap, their popular network scanner and mapper. The release features nearly 600 significant changes and the developers consider it to be "the most important Nmap release since 1997". Major improvements to the network scanner include the addition of the Ndiff scan comparison tool and the Nmap Scripting Engine
In this article we'll be using the awesome open-source nmap network scanning engine. In this example I will be preforming my scan from a Linux box. However you can use other OSs.