Nmap, or Network Mapper, is a free, open source tool that is available under the GNU General Public License as published by the Free Software Foundation. It is most often used by network administrators and IT security professionals to scan corporate networks, looking for live hosts, specific services, or specific operating systems. Part of the beauty of Nmap is its ability to create IP packets from scratch and send them out utilizing unique methodologies to perform the above-mentioned types of scans and more. This book provides comprehensive coverage of all Nmap features, including detailed, real-world case studies.

Amazon: http://www.amazon.com/Nmap-Enterprise-Guide-Network-Scanning/dp/1597492418
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