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 the purpose of each layer, the protocols, and the PDUs

In this section, we'll take a closer look at each of the seven layers of the OSI model and describe the following:

  • The layers of the OSI model, from layer seven to layer one: Application, Presentation, Session, Transport, Network, Data Link, and Physical.
  • The three layers that use source addressing and destination addressing during encapsulation: the Transport, Network, and Data Link layers.
  • The PDU for each layer, which defines what shape the data is in as it is passed to the layer above or the layer below.

In the following diagram, we can see a summary of the OSI model:

Figure 8.1 – The OSI model

Before diving into the layers, it is helpful to use a mnemonic device to remember the first letter of each layer. With the OSI, we have two, as shown in the following diagram:

Figure 8.2 – OSI mnemonics

Once you know the names of...