Book Image

Mastering Wireshark 2

By : Andrew Crouthamel
Book Image

Mastering Wireshark 2

By: Andrew Crouthamel

Overview of this book

Wireshark, a combination of a Linux distro (Kali) and an open source security framework (Metasploit), is a popular and powerful tool. Wireshark is mainly used to analyze the bits and bytes that flow through a network. It efficiently deals with the second to the seventh layer of network protocols, and the analysis made is presented in a form that can be easily read by people. Mastering Wireshark 2 helps you gain expertise in securing your network. We start with installing and setting up Wireshark2.0, and then explore its interface in order to understand all of its functionalities. As you progress through the chapters, you will discover different ways to create, use, capture, and display filters. By halfway through the book, you will have mastered Wireshark features, analyzed different layers of the network protocol, and searched for anomalies. You’ll learn about plugins and APIs in depth. Finally, the book focuses on pocket analysis for security tasks, command-line utilities, and tools that manage trace files. By the end of the book, you'll have learned how to use Wireshark for network security analysis and configured it for troubleshooting purposes.
Table of Contents (18 chapters)
Title Page
Copyright and Credits
Packt Upsell
Free Chapter
Installing Wireshark 2

TCP analysis II

In this section, we will take a look at filtering on many different TCP header fields, and what kind of issues we could see based on some of the fields that we look at.

So, what we can see in the following screenshot is a packet capture of the websites that were opened:

You can see we still have the TCP column enabled, so we can go down and find a TCP packet, and we'll see the field information again:

As with many of the other protocols that we've looked at, we can right-click on any of the fields and apply them as a filter. What we may want to do is expand the Flags, and look for anything that has the urgent bit set:

The urgent bit is not often used. The only one that we can think of is using Telnet, and what it does is it prioritizes the packets, basically. So what we can do is right-click on Urgent bit, and we'll go to Apply a Filter | Selected:

And we'll see that the filter's created, but it's based on 0. So we'll change it to 1:

Now, we will see whether there are any packets...