nmap: nmap (network scanner) nmap: nmap: Nmap ("Network Mapper") is an open source utility for network nmap: exploration or security auditing. It was designed to rapidly scan nmap: large networks, although it works fine against single hosts. Nmap nmap: uses raw IP packets in novel ways to determine what hosts are nmap: available on the network, what services (ports) they are offering, nmap: what operating system (and OS version) they are running, what type of nmap: packet filters/firewalls are in use, and dozens of other nmap: characteristics. Nmap runs on most types of computers, and both nmap: console and graphical versions are available.