With cyber-terrorism and corporate espionage threatening the fiber of our world, the need for trained network security professionals continues to grow. This book describes the tools and penetration testing methodologies used by ethical hackers to better understand how to protect computer networks. A thorough discussion is first established outlining what and who an ethical hacker is, and how important they are in protecting corporate and government data from cyber attacks. This title provides a structured knowledge base for preparing security professionals to understand how to protect a network using some of the skills and tools of a penetration or ethical hacker.