Nmap ("Network Mapper") is a free and open source (license) utility for network exploration or security auditing. Many systems and network administrators also find it useful for tasks such as network inventory, managing service upgrade schedules, and monitoring host or service uptime. Nmap uses raw IP packets in novel ways to determine what hosts are available on the network, what services (application name and version) those hosts are offering, what operating systems (and OS versions) they are running, what type of packet filters/firewalls are in use, and dozens of other characteristics. It was designed to rapidly scan large networks, but works fine against single hosts. Nmap runs on all major computer operating systems, and official binary packages are available for Linux, Windows, and Mac OS X. In addition to the classic command-line Nmap executable, the Nmap suite includes a flexible data transfer, redirection, and debugging tool (Ncat), and a utility for comparing scan results (Ndiff).
The software hosted in extras-testing is not ready for normal users! PLEASE use it only for testing purposes. Be ready to file proper bug reports instead of posting complaints. Potential problems: crashes, battery drain, poor system performance, full disk space & more - SERIOUSLY! Backing up your data is recommended. In case of trouble you might need to re-flash your device.