Before I start my review of this book, let me narrate a story. Recently I had a crisis at work where certain users were not able to invoke web services. Of course, we had well-tested software using agile methodology and all that. My team knew our front-end and our backend very well. What we weren't well-versed with was the connection by which our front-end communicated with the backend. We were in a war room with the networking experts for 2 days and I couldn't understand jack of what they were talking. I was clearly an "outsider" in their elite circle. Hence, I got interested in this book.
This book is divided into seven chapters starting with networking models (OSI, TCP/IP) and ending with subnetting. Most of the material is dry but the author keeps the flow going steadily by providing screen printouts of Wireshark and explaining it with his pedantic style. Questions, answers, and exercises at the end of each chapter reinforce your learning. I liked chapter 5 (Network equipment) and Chapter 7 (Subnetting) very much as it is explained well and also I can relate it to my work.
This book is certainly not for the faint of heart. It is not your grand-father's "Hello World" book. In fact, it reads like a computer science text book. The author has pain-stakingly tried to simplify it as much as he could. As Einstein said, "Keep it simple but not any simpler". A background in networking would help refresh your knowledge and this book serves exactly that. If you are an absolute beginner looking for a basic book on networking, this book is not for you. However, if it's been a few years since your last networking class, you should be able to pick things up with the help of this book.