Preface
Wireshark has long become the market standard for network analysis, and with the growth of the Internet and TCP/IP-based networks, it became very popular for network analysis, troubleshooting, as well as for R&D engineers to understand what is actually running over the network and what are the problems that we face.
This book is written from a practical point of view. The first part of it, from Chapter 1, Introducing Wireshark, to Chapter 6, Using the Expert Infos Window, describes the Wireshark software and how to work with it. This includes how to start it, where to locate it in the network, how to work with statistical tools, and how to use the Expert system. The second part, from Chapter 7, Ethernet, LAN Switching, and Wireless LAN, to Chapter 14, Understanding Network Security, describes how to use it for the analysis and troubleshooting of common networking protocols; among them, the TCP/IP protocol stack with emphasis on TCP performance issues, common Internet protocols such as HTTP, SMTP, POP and DNS, databases, Citrix and Microsoft Terminal Server, IP telephony, and multimedia applications. The last chapter is about network security. It describes how to locate security breaches and other problems in your network.
As the name of the book implies, this is a Cookbook. It is a list of effective, targeted recipes of how to analyze networks. Every recipe comes with a specific issue, how to use Wireshark for it, where to look and what to look for, and what is the reason for what you see. To complete the picture, every recipe provides the theoretical foundations of the subject, in order to give the reader the required theoretical background.
You will see many examples in the book, and all of them are real cases. Some of them took me minutes to solve, some hours, and some of them took many days. There is one thing common to all of them: work systematically, use the proper tools, try to get inside the head of the application writer, and like someone told me once, "Try to think like the network". Do this, use Wireshark, and you will get results. The purpose of this book is to try and get you there. Have fun!
