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

Outlining IPv4

In 1981, Request for Comments (RFC) 791 outlined the specifications for IPv4. The RFC outlined that IPv4 had two principal tasks, addressing and fragmentation, as defined in Section 1.4. Operation, found at https://tools.ietf.org/html/rfc791#section-1.4.

As stated, one of the original roles of IPv4 was fragmentation, which breaks packets apart. At the time, this was necessary because, in the early 1980s, most of the networks had limited bandwidth and were unable to transmit large packets.

Over time, efforts have been made to upgrade and replace the antiquated data pathways, and much of the internet has been replaced by high-speed, fiber optic cables. As a result, in today's networks, fragmentation is rarely used.

Note

Fragmentation is used when the maximum transmission unit (MTU) is less than 1,500 bytes.

As time has passed, we can see that IPv4 is still influential in addressing, along with the role of routing, in order to get data to its final...