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

Simple Mail Transfer Protocol (SMTP)


SMTP is used widely to send and receive emails over a small network. The protocol uses the Sender-SMTP process to send emails and the Receiver-SMTP process to receive emails. This makes SMTP a client-server-based protocol that runs over port 25.

Typically, an SMTP channel for mail transfer is created through a successful TCP three-way handshake followed by a series of SMTP packets:

In our lab, we have an SMTP server configured at IP 192.168.1.105 and a client at IP 192.168.1.104. The client will request the server to sends an email to an address known to the client. The server will respond to this request with numerical code, followed by a brief response parameter.

Dissecting SMTP communication packets

Using the Netcat client from a Kali Linux machine, I will connect to the SMTP mail service running on a Windows machine. After a successful three-way handshake, the server will respond with numerical codes with a short summary. Follow these steps to the send...