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

Exploring ARP headers and fields

While in a trace file, if you enter arp in the display filter, you will most likely see a series of ARP requests and replies. Within each ARP header, there are several field values, such as Operation Code (Opcode), sender, and target IP address, which help ensure that the ARP requests/replies are received. Let's first take a look at a typical ARP transaction.

Identifying a standard ARP request/reply 

Open ARPTrace.pcapng, and take a look at the first two packets, which are the ARP request/reply. Expand each ARP request/reply, and you will see that ARP is wrapped in an Ethernet frame. However, there are no network or transport layer headers.

First, let's investigate the components of an ARP request.

Inspecting an ARP request

To view a standard ARP request, expand Frame 1. Once expanded, you can see that there are several field values, which provide information about...