What does it do?
NetStat is a utility that is built into most UNIX releases. It allows
you to see any existing IP connections. This includes any "Listening" ports,
established connections and connections waiting to be closed.
How do I use it?
Open a NetStat Window. At first the "TCP" connections will be shown. To display "UDP" connections, click "UDP". By default, NetStat will display all the sockets available to it, however sometimes this is difficult to read, especially if you are using it on a server. There are two check boxes that when un-ticked can filter out some of the less-important sockets, leaving you with just the useful ones. The "Show Empty Sockets" box, when unchecked, will clear out any sockets that have been instantiated by processes on your Mac, but aren't being used. The "Show Local Sockets" box, will similarly hide any sockets that your Mac has opened upon itself. These sockets are called "loopback" connections and are used by processes on your mac to talk to one-another.
© Charlie Boisseau 2005