Network Troubleshooting Tools

Chapter 9. Testing Connectivity Protocols

This chapter and the next describe tools used to investigate protocol-specific behavior. In this chapter, I describe tools used to explore connectivity protocols, protocols that work at the network and transport levels to provide connectivity. Chapter 10 focuses on tools used in testing protocols at the application level.

I begin with a description of packet generation tools. Custom packet generators, like hping and nemesis, will allow you to create custom packets to test protocols. Load generators, like MGEN, will let you flood your network with packets to see how your network responds to the additional traffic. We conclude with a brief discussion of network emulators and simulators.

Many of the tools described in this chapter and the next are not tools that you will need often, if ever. But should the need arise, you will want to know about them. Some of these tools are described quite briefly. My goal is to familiarize you with the tools rather than to provide a detailed introduction. Unless you have a specific need for one of these tools, you’ll probably want to just skim these chapters initially. Should the need arise, you’ll know the appropriate tool exists and can turn to the references for more information.

Packet Injection Tools

This first group of tools generates and injects packets into your network. Basically, there are two different purposes for generating packets, each with its own general approach and its own set of tools. ...