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 User Datagram Protocol


As defined in RFC 768, a UDP is a connectionless protocol, which is great for transmitting real-time data between hosts and is often termed as an unreliable form of communication. The reason is, UDP doesn't care about the delivery of packets, and any lost packets are not recovered because the sender is never informed about the dropped or discarded packets. However, many protocols such as DNS, TFTP, SIP, and so on. rely only on this.

The protocols that use UDP as a transport mechanism should rely upon other techniques to ensure data delivery and error-checking. A point to note is that UDP provides faster transmission of packets as it does not perform three-way handshake or graceful termination as observed in the TCP. UDP is referred to as a transaction-oriented protocol and not a message-oriented protocike a Tol lCP.

The UDP header

The size of a usual UDP header is 8 bytes; the data that is added with the header can be theoretically 65,535 (practically 65,507) bytes...