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

Reviewing the network layer

The network layer (or layer 3) has two key roles: addressing and routing data. This layer provides addressing using a logical IP address. In addition, the network layer determines the best logical path to take for packets that travel through other networks so they can get to their destination. It does this by communicating with other devices during the routing process.

As shown in the figure, the network layer has three main protocols, IP, ARP, and ICMP, which are essential in delivering data:

Figure 11.1 – The OSI model—network layer

In addition to IP, the other protocols include the following:

  • Address Resolution Protocol (ARP): ARP resolves an IPv4 address (network layer) to a Media Access Control (MAC) (data link layer) address on a local area network so the frame can be delivered to the appropriate host. ARP is shown between layer 3 and layer 2, and as a result, many consider ARP as a layer 3 protocol...