Watching Network Traffic

One of the biggest difficulties for network programmers is not being able to see exactly what is happening on the network. Often you think you have created the perfect client/server application, spending hours working out the mechanics of sending and receiving application data among machines, only to find out that somewhere along the network your data is not getting through. A network analyzer can be the network programmer’s best friend in finding out what is happening “on the wire.” Programming errors can often be detected by watching application data pass from one device to another.

This section shows how to install a simple public-domain network analyzer on your Windows workstation or server to help you debug network programming problems.

Note

If you are developing C# programs on a Windows NT 4 or 2000 server, you already have a network analyzer program built into your system: netmon. This program offers a way to capture and view network packets that enter and leave the server. Unfortunately, this program is not available on other Windows platforms. Therefore, to be consistent for all C# development platforms, this chapter discusses implementation of a public-domain network analyzer that operates on all Windows platforms on which the .NET Framework runs. This analyzer is the WinPcap driver and its associated tools, WinDump and Analyzer.