Nmap

Nmap (“Network Mapper”) discovers hosts and services on a network by sending packets and analysing the responses. It is the standard first step in network inventory and security audits.

Common uses

• Host discovery and asset inventory.
• Open port and service version detection.
• OS fingerprinting.
• Scripted checks with the Nmap Scripting Engine (NSE).

First scan

The Nmap project provides scanme.nmap.org as a host you are allowed to scan for learning:

nmap -sV scanme.nmap.org

Only scan networks you own or have written permission to test.