Book Image

Learn Wireshark, - Second Edition

By : Lisa Bock
5 (1)
Book Image

Learn Wireshark, - Second Edition

5 (1)
By: Lisa Bock

Overview of this book

Wireshark is a popular and powerful packet analysis tool that helps network administrators investigate latency issues and potential attacks. Over the years, there have been many enhancements to Wireshark’s functionality. This book will guide you through essential features so you can capture, display, and filter data with ease. In addition to this, you’ll gain valuable tips on lesser-known configuration options, which will allow you to complete your analysis in an environment customized to suit your needs. This updated second edition of Learn Wireshark starts by outlining the benefits of traffic analysis. You’ll discover the process of installing Wireshark and become more familiar with the interface. Next, you’ll focus on the Internet Suite and then explore deep packet analysis of common protocols such as DNS, DHCP, HTTP, and ARP. The book also guides you through working with the expert system to detect network latency issues, create I/O and stream graphs, subset traffic, and save and export captures. Finally, you’ll understand how to share captures using CloudShark, a browser-based solution for analyzing packet captures. By the end of this Wireshark book, you’ll have the skills and hands-on experience you need to conduct deep packet analysis of common protocols and network troubleshooting as well as identify security issues.
Table of Contents (28 chapters)
1
Part 1 Traffic Capture Overview
6
Part 2 Getting Started with Wireshark
11
Part 3 The Internet Suite TCP/IP
16
Part 4 Deep Packet Analysis of Common Protocols
21
Part 5 Working with Packet Captures

Comprehending display filters

While capturing traffic, or analyzing a pre-captured file, display filters help to narrow the scope and home in on specific types of traffic. It's not uncommon to have a capture with over 3,000 packets containing many different types of traffic.

When you launch Wireshark, you will see the startup screen. Across the top, below the icons, is the filter toolbar. Within the toolbar is the text Apply a display filter…, where you can easily apply and edit display filters, as shown here:

Figure 7.6 – Wireshark startup screen

You can create a simple filter on any of the protocols Wireshark supports by using a single protocol or adding a logical operator. For example, if you want to see TCP or ARP traffic, then you would use the tcp || arp display filter.

Wireshark's display filters can easily be modified. The following section illustrates how you can edit the display filters to customize your workflow.

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