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

Comparing TCP stream graphs

While an I/O graph provides the ability to visualize traffic flowing in both directions, there are times you want to focus on the traffic flowing in a single direction. That is where the value of TCP stream graphs come into play. The graphs will help provide ways to visualize the different streams in a capture.

To see what's available, go to Statistics | TCP Stream Graphs, as shown here:

Figure 19.14 – TCP Stream Graphs menu

Once in the TCP Stream Graphs submenu, you can see there are multiple choices. You can select any of the graphs, which will bring up a single window. Once in the window, you can select any one of the five choices.

Let's start with viewing time sequence graphs.

Using time sequence graphs

A time sequence graph will chart sequence numbers over time. When you first launch the graph, you will need to make sure you select the correct direction, as only one direction will be of value...