Each regular host in the network is represented by a little circle. The color and size of the circleis determined by the number of open ports on the host. The more open ports, the larger the circle.A white circle represents an intermediate host in a network path that was not port scanned. If ahost has fewer than three open ports, it will be green; between three and six open ports, yellow;more than six open ports; red.The Nmap Security Scanner is a free and open source utility used by millions of peoplefor network discovery, administration, inventory, and security auditing. Nmap uses raw IPpackets in novel ways to determine what hosts are available on a network, what services(application name and version) those hosts are offering, what operating systems they arerunning, what type of packet filters or firewalls are in use, and more. Nmap was named"Information Security Product of the Year" by Linux Journal and Info World. It was also usedby hackers in seven movies, including The Matrix Reloaded, Die Hard 4, and The BourneUltimatum. Nmap runs on all major computer operating systems, plus the Amiga. Atraditional command-line interface and the Zenmap GUI are included:About