Book Image

Wireshark 2 Quick Start Guide

By : Charit Mishra
Book Image

Wireshark 2 Quick Start Guide

By: Charit Mishra

Overview of this book

<p>Wireshark is an open source protocol analyser, commonly used among the network and security professionals. Currently being developed and maintained by volunteer contributions of networking experts from all over the globe. Wireshark is mainly used to analyze network traffic, analyse network issues, analyse protocol behaviour, etc. - it lets you see what's going on in your network at a granular level. This book takes you from the basics of the Wireshark environment to detecting and resolving network anomalies.</p> <p>This book will start from the basics of setting up your Wireshark environment and will walk you through the fundamentals of networking and packet analysis. As you make your way through the chapters, you will discover different ways to analyse network traffic through creation and usage of filters and statistical features. You will look at network security packet analysis, command-line utilities, and other advanced tools that will come in handy when working with day-to-day network operations.</p> <p>By the end of this book, you have enough skill with Wireshark 2 to overcome real-world network challenges.</p>
Table of Contents (14 chapters)
Title Page
Packt Upsell
Contributors
Preface
8
Mastering the Advanced Features of Wireshark
Index

The transmission control protocol


TCP is a connection-oriented protocol used by several application-layer protocols to ensure data delivery without any loss of information during transition, based on sequence and acknowledgment numbers. TCP ensures fail-proof delivery of packets between nodes. TCP sits in between the network layer and the application layer and uses the IP datagram to transfer data packets between the sender and receiver.

The Three-Way Handshake process takes place before the data transfer happens. A TCP connection is like a two-way communication process where not only the sender is actively involved, but even the receiver sends acknowledgments to make it a reliable form of connection.

Understanding the TCP header and its various flags

The TCP header is normally 20 bytes long, but at times, due to the presence of the Options field, the TCP header size can vary up to 60 bytes. The following is an illustration of a simplified TCP header:

The following is a brief explanation for...