Nmap (Network Mapper) is a free and open-source network scanner created by Gordon Lyon (also known by his pseudonym Fyodor Vaskovich).Nmap is used to discover hosts and services on a computer network by sending packets and analyzing the responses.
Nmap provides a number of features for probing computer networks, including host discovery and service and operating system detection. These features are extensible by scripts that provide more advanced service detection,vulnerability detection,and other features. Nmap can adapt to network conditions including latency and congestion during a scan.
- Host discovery – Identifying hosts on a network. For example, listing the hosts that respond to TCP and/or ICMP requests or have a particular port open.
- Port scanning – Enumerating the open ports on target hosts.
- Version detection – Interrogating network services on remote devices to determine application name and version number.
- TCP/IP stack fingerprinting – Determining the operating system and hardware characteristics of network devices based on observations of network activity of said devices.
- Scriptable interaction with the target – using Nmap Scripting Engine(NSE) and Lua programming language.