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. Un-patched software on network operating systems and hardware can be a common point of attack for an intruder. Vulnerability analysis will often identify outdated software and exploitation is soon to follow. This book, the fourth in the series, prepares the practitioner to create and administer effective policies and best practices in patch management, OS configuration and analysis to identify potential Network Security Weaknesses.