Install Nmap
Open a terminal or command prompt
Run a basic host discovery scan: `nmap 192.168.1.1`
Scan a range of hosts: `nmap 192.168.1.0/24`
Scan specific ports: `nmap -p 22,80,443 192.168.1.1`
Scan all ports: `nmap -p- 192.168.1.1`
Detect service versions: `nmap -sV 192.168.1.1`
Detect operating system: `nmap -O 192.168.1.1`
Perform an aggressive scan: `nmap -A 192.168.1.1`
Run a ping scan only: `nmap -sn 192.168.1.0/24`
Save results to a file: `nmap -oN scan.txt 192.168.1.1`
Save results in XML format: `nmap -oX scan.xml 192.168.1.1`
Increase verbosity: `nmap -v 192.168.1.1`
Use a faster timing template: `nmap -T4 192.168.1.1`
Scan with a custom script: `nmap –script default 192.168.1.1`
Check Nmap help: `nmap –help`
Review results and identify open ports, services, and versions
Use only on systems you own or have permission to test