Nmap is an advanced utility for network exploration or security auditing. It supports ping scanning, many port scanning techniques, TCP/IP fingerprinting (remote OS detection), advanced host enumeration, firewall bypassing, flexible target and port specification, decoy scanning, determination of TCP sequence predictability characteristics, sunRPC scanning, reverse-identd scanning, and more.
You can download it from the following link: https://packetstormsecurity.com/files/download/17544/nmap-2.30BETA20.tgz
Source: https://packetstormsecurity.com/files/17544/Nmap-Scanning-Utility-2.30-BETA-20.html