Book Image

Network Analysis using Wireshark Cookbook

By : Yoram Orzach
Book Image

Network Analysis using Wireshark Cookbook

By: Yoram Orzach

Overview of this book

Is your network slow? Are your users complaining? Disconnections? IP Telephony problems? Video freezes? Network analysis is the process of isolating these problems and fixing them, and Wireshark has long been the most popular network analyzer for achieving this goal. Based on hundreds of solved cases, Network Analysis using Wireshark Cookbook provides you with practical recipes for effective Wireshark network analysis to analyze and troubleshoot your network. "Network analysis using Wireshark Cookbook" highlights the operations of Wireshark as a network analyzer tool. This book provides you with a set of practical recipes to help you solve any problems in your network using a step-by-step approach. "Network analysis using Wireshark Cookbook" starts by discussing the capabilities of Wireshark, such as the statistical tools and the expert system, capture and display filters, and how to use them. The book then guides you through the details of the main networking protocols, that is, Ethernet, LAN switching, and TCP/IP, and then discusses the details of application protocols and their behavior over the network. Among the application protocols that are discussed in the book are standard Internet protocols like HTTP, mail protocols, FTP, and DNS, along with the behavior of databases, terminal server clients, Citrix, and other applications that are common in the IT environment. In a bottom-up troubleshooting approach, the book goes up through the layers of the OSI reference model explaining how to resolve networking problems. The book starts from Ethernet and LAN switching, through IP, and then on to TCP/UDP with a focus on TCP performance problems. It also focuses on WLAN security. Then, we go through application behavior issues including HTTP, mail, DNS, and other common protocols. The book finishes with a look at network forensics and how to search and find security problems that might harm the network.
Table of Contents (23 chapters)
Network Analysis Using Wireshark Cookbook
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Configuring coloring rules and navigation techniques


Coloring rules define how Wireshark will color protocols and events in the captured data. Working with the coloring rules will help you a lot with network troubleshooting, since you are able to see different protocols in different colors, and you can also configure different colors for different events.

Coloring rules enable you to configure new coloring rules according to various filters. It will help you to configure different coloring schemes for different scenarios and save them in different profiles. In this way you can configure coloring rules for resolving TCP issues, rules for resolving Sip and Telephony problems, and so on.

Tip

You can configure Wireshark Profiles in order to save Wireshark configuration; for example, predefined colors, filters, and so on. To do so, navigate to Configuration Profiles from the Edit menu.

Getting ready

To start with the coloring rules, proceed as follows:

  1. Go to the View menu.

  2. On the lower part of the menu, choose Coloring Rules. You will get the following window:

How to do it...

We will now move on to the coloring rules:

Click on the New button, and you will get the following window:

In order to configure a new coloring rule, follow these steps:

  1. In the Name field, fill in the name of the rule. For example, fill in NTP for the Network Time Protocol.

  2. In the String field, fill in the filter string, that is, what you want the rule to show (we will talk about display filters in Chapter 3, Using Display Filters). You can click on the expression button and get a list of preconfigured filters.

  3. Click on the Foreground Color button and choose the foreground color for the rule. This will be the foreground color of the packet in the packet list.

  4. Click on the Background Color button and choose the background color for the rule. This will be the background color of the packet in the packet list.

  5. Click on the Edit button if you want to edit an existing rule. You can also either click on the Import button to import an existing coloring scheme, or click on the Export rule for exporting the current scheme.

Tip

There is an importance to the order of the coloring rules. Make sure the order that the coloring rules are in is the order of implementation. For example, application layer protocols should come before TCP or UDP, so that Wireshark colors them in their color and not the regular TCP or UDP color.

How it works...

Like many operations in Wireshark, you can configure various operations on the data that is filtered. The coloring rules mechanism simply applies a coloring rule to a predefined filter.

See also

You can find various types of coloring schemes at http://wiki.wireshark.org/ColoringRules, along with many other examples, in a simple Internet search.