"The book you are about to read will arm you with the knowledge you need to defend your network from attackers—both the obvious and the not so obvious.... If you are new to network security, don't put this book back on the shelf! This is a great book for beginners and I wish I had access to it many years ago. If you've learned the basics of TCP/IP protocols and run an open source or commercial IDS, you may be asking 'What's next?' If so, this book is for you." —Ron Gula, founder and CTO, Tenable Network Security, from the Foreword "Richard Bejtlich has a good perspective on Internet security—one that is orderly and practical at the same time. He keeps readers grounded and addresses the fundamentals in an accessible way." —Marcus Ranum, TruSecure "This book is not about security or network monitoring: It's about both, and in reality these are two aspects of the same problem. You can easily find people who are security experts or network monitors, but this book explains how to master both topics." —Luca Deri, ntop.org "This book will enable security professionals of all skill sets to improve their understanding of what it takes to set up, maintain, and utilize a successful network intrusion detection strategy." —Kirby Kuehl, Cisco Systems Every network can be compromised. There are too many systems, offering too many services, running too many flawed applications. No amount of careful coding, patch management, or access control can keep out every attacker. If prevention eventually fails, how do you prepare for the intrusions that will eventually happen? Network security monitoring (NSM) equips security staff to deal with the inevitable consequences of too few resources and too many responsibilities. NSM collects the data needed to generate better assessment, detection, and response processes—resulting in decreased impact from unauthorized activities. In The Tao of Network Security Monitoring , Richard Bejtlich explores the products, people, and processes that implement the NSM model. By focusing on case studies and the application of open source tools, he helps you gain hands-on knowledge of how to better defend networks and how to mitigate damage from security incidents. Inside, you will find in-depth information on the following areas. The NSM operational framework and deployment considerations. How to use a variety of open-source tools—including Sguil, Argus, and Ethereal—to mine network traffic for full content, session, statistical, and ale...