Security Portal: NMAP - not kiddiez stuff -- Industrial strength port scanning for LinuxJul 21, 1999, 05:07 (0 Talkback[s])
"Nmap is the premier open source port scanning tool, and provides several powerful methods to analyze weaknesses in a TCP/IP network..."
"Nmap is open source and falls under the GNU public license. NMAP works with several different flavors of Unix, but is most commonly seen running under Linux, where it has no limitations of its features. What makes nmap such a powerful tool is its ability to create and transmit unusual TCP/IP packets and sequences."
"Use nmap to audit your firewall and/or Intrusion Detection systems' capabilities. Nmap uses many stealth scanning techniques. By auditing your firewall logs, you can determine if it is catching your scans, and if it is providing proper notification."
"Determine which TCP and UDP ports are open on your host systems. Obviously, this is what port scanning software is for. The ability for nmap to detect open UDP ports is a differentiator between it and other products."