You're reading from Learn Wireshark A definitive guide to expertly analyzing protocols and troubleshooting networks using Wireshark

Product type Paperback

Published in Aug 2022

Publisher Packt

ISBN-13 9781803231679

Length 606 pages

Edition 2nd Edition

Languages

TCP

Tools

Wireshark

Concepts

Networking

Author (1):

Lisa Bock

View More author details

Table of Contents (28) Chapters

Preface

1. Part 1 Traffic Capture Overview

2. Chapter 1: Appreciating Traffic Analysis FREE CHAPTER

3. Chapter 2: Using Wireshark

4. Chapter 3: Installing Wireshark

5. Chapter 4: Exploring the Wireshark Interface

6. Part 2 Getting Started with Wireshark

7. Chapter 5: Tapping into the Data Stream

8. Chapter 6: Personalizing the Interface

9. Chapter 7: Using Display and Capture Filters

10. Chapter 8: Outlining the OSI Model

11. Part 3 The Internet Suite TCP/IP

12. Chapter 9: Decoding TCP and UDP

13. Chapter 10: Managing TCP Connections

14. Chapter 11: Analyzing IPv4 and IPv6

15. Chapter 12: Discovering ICMP

16. Part 4 Deep Packet Analysis of Common Protocols

17. Chapter 13: Diving into DNS

18. Chapter 14: Examining DHCP

19. Chapter 15: Decoding HTTP

20. Chapter 16: Understanding ARP

21. Part 5 Working with Packet Captures

22. Chapter 17: Determining Network Latency Issues

23. Chapter 18: Subsetting, Saving, and Exporting Captures

24. Chapter 19: Discovering I/O and Stream Graphs

25. Chapter 20: Using CloudShark for Packet Analysis

26. Assessments

27. Other Books You May Enjoy

Creating I/O graphs

An I/O graph provides a way to analyze traffic flowing in both directions and can be created using a live capture or an existing trace file.

To generate graphs on a specific stream, return to bigFlows.pcap. In the display filter, enter tcp.stream eq 198 and run the filter. Once Wireshark presents the information, we'll reduce the file by going to File | Export Specified Packets…, which will bring up this window:

Figure 19.7 – Export Specified Packets window

Make sure you have selected All Packets | Displayed, as shown in Figure 19.7. Then, save the file as Flow198.pcap.

Close bigFlows.pcap and then open Flow198.pcap, where we will see evidence of a congested network.

Examining errors

Within Flow198.pcap, you'll see several areas of concern, as the intelligent scroll bar is littered with black lines, which generally indicates signs of latency. By clicking on one of the black striped areas on the scroll...