What is Nmap?

Nmap is a network scanner created by Gordon Lyon.

It is used to discover hosts and services on a computer network by sending packets and analyzing the responses. It provides a number of features for probing computer networks, including host discovery and service and operating system detection.

Some feature of Nmap

1. 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.

2. Port scanning – Enumerating the open ports on target hosts.

3. Version detection – Interrogating network services on remote devices to determine application name and version number.

4. OS detection – Determining the operating system and hardware characteristics of network devices.

5. Script scan – using Nmap Scripting Engine (NSE) and Lua programming language.

Target scanning

scan a single target:

$ nmap 192.168.0.1

scan multiple targets:

$ nmap 127.0.0.1 192.168.0.1

scan a domain:

$ nmap example.com

scan a whole network:

$ nmap 127.0.0.1/24

scan multiple targets with IP range:

$ nmap 192.168.1.1-200

excluding a target from a IP range:

$ nmap 192.168.1.1/24 --exclude 192.168.1.1