The Network Defense Series from EC-Council | Press is comprised of 5 books designed to educate learners from a vendor-neutral standpoint how to defend the networks they manage. This series covers the fundamental skills in evaluating internal and external threats to network security and design, how to enforce network level security policies, and how to ultimately protect an organization's information. The books in the series cover a broad range of topics from secure network fundamentals, protocols & analysis, standards and policy, hardening infrastructure, to configuring IPS, IDS, firewalls, bastion host and honeypots. Learners completing this series will have a full understanding of defensive measures taken to secure their organization's information, and along with the proper experience these books will prepare readers for the EC-Council Network Security Administrator (E|NSA) certification. Proactive vulnerability assessment is key to any organization's security posture. Constant assessment for potential weakness is required to maintain a security edge as new vulnerabilities in operating systems, software, hardware, and even human elements are identified and exploited every day. This book, the fifth in the series, is designed to provide the fundamental knowledge necessary to comprehend overall network security posture and the basic practices in vulnerability assessment.