Network Troubleshooting Tools

Chapter 10. Application-Level Tools

This chapter briefly surveys some additional tools that might be of interest. You will not need tools that are useful when setting up and debugging programs using application-level protocols. The chapter is organized around different application protocols. You will not need the tools described here often. The goal of this chapter is to make you aware of what is available should the need arise, and the approach described here may be more useful than the specific tools mentioned. Unless you have a specific problem, you’ll probably want to just skim this chapter the first time through.

Application-Protocols Tools

Many network applications are built upon application-level protocols rather than being built directly upon network- or transport-level protocols. For example, email readers typically use SMTP to send email and POP2, POP3, or IMAP to receive email. For some applications, it is difficult to distinguish the application from the underlying protocol. NFS is a prime example. But when an implementation separates the application from its underlying protocol, a number of advantages can be realized. First, the separation helps to ensure interoperability. A client developed on one platform can communicate effectively with server software running on a different system. For example, your web browser can communicate with any web server because it uses a standardized protocol—HTTP. Tools based on the underlying protocol can be used to obtain basic information ...