Nmap is a tool for scanning and evaluation of hosts in a computer network, and thus falls into the category of port scanner. The name stands for Network Mapper.
Nmap was originally developed by a well-known with the nickname Fyodor hackers for the Linux operating system. The text-based program under the GNU General Public License, making it free software, but can also be acquired free of charge under an alternative license ( to use it, for example, within non- GPL software). In addition to the text-based, there is the graphical user interface nmapfe for convenient setting of Nmap, which has now been superseded by the Zenmap called GUI. Although nmap was originally a Unix tool, there is now also a port to Windows operating systems. It provides almost full functionality, however, has some limitations.
Nmap is primarily for port scanning (ie, examining the ports of a host ) are used. The tool has been constantly expanded and was able to make, especially through the active techniques for OS fingerprinting ( detecting the operating system used on the destination host ) name. Also the mapping of environments (detection of active hosts ) is possible.
Nmap is very popular with both attackers as well as administrators, as it is very efficient and reliable. It is an important component in the network diagnostics and analysis of network-enabled systems. Among other things, it is also used by the Nessus Vulnerability Scanner to detect open ports.
In some films Nmap occurs: In The Matrix Reloaded, the character Trinity hacks using the SSH1 CRC32 2001 discovered exploit in a motor drive, after having the computer with Nmap scan. In the movie " Battle Royale " the source of Nmap is shown. Furthermore, in The Bourne Ultimatum used the then beta version 4.01 with the graphical interface Zenmap.