This book covers a broad range of Networking Security. Topics that are generally overlooked in most cases. This book is very general in terms of Overall network security and makes you take a step back and review your security procedures and policies. Easy to understand and follow. A great reference guide to go back to also. The reason I gave this book 4 instead of 5 stars is because I feel that a few of the topics should've been covered a little more deeply. A few topics that were covered left me with an incomplete feeling. Like I need to learn more about it. I guess that's what guides usually do. It's a compromise between buying a book that covers one subject/topic very well or something that enlightens you to all subjects/topics that you may have overlooked. All in all.. Great Book. I would buy it again if I lost this copy.