TCP/IP is a very complex protocol suite, as I am sure you would agree after perusing the contents of this Guide. It is actually quite amazing that most of the time, all of the different protocols, services and programs perform their jobs both efficiently and silently. Most of us don’t even realize just how much is going on in the background, and that’s as it should be. J On the other hand, when a problem does occur on a TCP/IP network, the administrator charged with fixing it needs to obtain as much information as possible about what all those bits and pieces of the suite are doing behind the scenes. The network status utility, netstat, is provided for this purpose.

The netstat program is very simple in concept, being designed for only one purpose: to show information about the operation of TCP/IP on a device. The aforementioned complexity of TCP/IP, however, leads to netstat being rather elaborate itself: the program can provide a large variety of information. As usual, the options and output of netstat depend on the particular operating system type and version. It is somewhat different on UNIX and Windows machines, so I will describe each platform separately.