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 suits all levels of security and networking professionals. A 42-page reference guide documents every Nmap feature and option, while the rest of the book demonstrates how to apply those features to quickly solve real-world tasks. Examples and diagrams show actual communication on the wire.