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

Discovering expert information

While analyzing a packet capture, you may observe a colored circle in the lower left-hand corner of the interface. That is the Expert Information guide, which is a feature built within Wireshark that helps to alert the network administrator of possible issues once a capture has been made.

As shown in Figure 17.8 in the Exploring the Intelligent Scrollbar section, the expert information icon is a red circle, which indicates an error; this is the highest expert information level.

Return to the bigFlows.pcap packet capture. Double-click the expert information icon in the lower left-hand corner, which will open a console, as shown in the following screenshot:

Figure 17.13 – Expert Information grouped by severity

This may take a few minutes to load, depending on the size of the capture. In addition, there may be a lot of information.

The Expert Information console is a GUI that allows you to see details of what Wireshark...