Netstat

Ever wonder what network activity is happening on your machine? Use netstat.

The most useful command line options:

• -a = show all network access
• -b = shows the process, or on windows the process id that is using the network (the process id can be matched up to a process via the task manager)
• -n = don’t do a dns lookup

You can obviously chain this command together with grep:

• netstat -anb | grep 80