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

Understanding UDP

UDP is a lightweight, connectionless protocol used for data transfer. UDP does not have a handshake or connection process, nor does it have a teardown.

To see all your active UDP connections on a Windows machine, open a command line and run netstat -anp udp, as shown in the following screenshot:

Figure 9.23 – Netstat command showing UDP connection status

UDP doesn't have any ordering or reliability services; it simply delivers the data. Because of this, there isn't a need for a foreign (or remote) IP address and port. As a result, as shown in Figure 9.23, you will see only a local IP address and port for UDP.

Because of UDP's streamlined nature, it is an appropriate protocol for time-sensitive applications such as the following:

  • Dynamic Host Configuration Protocol (DHCP)
  • Domain Name System (DNS)
  • Trivial File Transfer Protocol (TFTP)
  • Voice over Internet Protocol (VoIP)

UDP is a lightweight...