If you’ve ever wondered how to find rogue devices on a network, scan other networks for interesting machines, rapidly find out what operating systems or software service versions are running on hosts on a given network and a whole bunch more, then NMAP is the free, open-source tool for you. And boy, you’re in for a treat, because here’s a full tutorial, courtesy of Al’s Geek Lab. There’s enough in this video to make you a competent network reconnaissance individual. Remember, with great power, comes great responsibility, so use this information wisely and legally!