How to Use the Port Scanner in Mac OS X Network Utility
Mac OS X comes with a bundled port scanner tool, just one of a variety of features tucked into the ever useful Network Utility app. That means you don’t need to bother with the command line or install more advanced tools like nmap to quickly scan for open ports on a given IP or domain, instead you can do it all through the friendly graphical interface. Despite being a fairly advanced utility, it’s actually very easy to use.