Nmap

Nmap (Network Mapper) is the global benchmark open-source network scanner and security auditing tool designed to discover hosts, open network ports, active services, and operating system fingerprints across local subnets and vast enterprise networks. Originally released by Gordon Lyon (Fyodor), Nmap uses raw IP packets in creative ways to determine which devices are live on a network, what network services (application name and version) those hosts are running, what operating systems they run, and what type of packet filters or firewalls are in use. Security auditors, network administrators, and penetration testers rely on Nmap for network inventory, managing service upgrade schedules, and monitoring host or service uptime. Nmap offers a broad spectrum of scan techniques—including TCP SYN stealth scanning, UDP scanning, TCP connect scanning, and idle zombie scanning—enabling practitioners to evaluate network perimeters without triggering intrusive connection states. With its highly extensible Nmap Scripting Engine (NSE), users can automate advanced vulnerability detection, backdoor discovery, and network exploitation checks using lightweight Lua scripts. By delivering unmatched speed, granular raw socket control, and comprehensive network diagnostics across all operating systems, Nmap remains the foundational network reconnaissance platform for cybersecurity professionals worldwide.