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.