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

Domain Name System (DNS)


Imagine a world of internet where you have to type a random numerical value (IP address) in your web browser's address bar, instead of a name, to visit a website. Also, imagine that each numerical figure is different. Considering this, how many numbers (IP addresses) can you memorize? 5? 10? Perhap, 50 at max? So, now, you are confined to visiting just 50 websites.

For the sake of a limitless web experience, DNS comes to our rescue. DNS stores a dataset (zone file) of website names mapped to their current IP addresses, along with the names of the domains. Each entry in the zone file is termed a resource record (combination of website name and its IP). DNS uses TCP and UDP, both for different purposes, over the port 53 by default.

How does DNS work? So, as a client, when you try to visit a website from a browser, your request (DNS query) is sent to an internal DNS server (if any) that looks up the resource records it contains. If the DNS server knows the IP address...