Nmap cheat sheet for beginners

Nmap is the main network reconnaissance tool. Below are the flags you need 90% of the time. Only scan your own systems or ones you have written permission for.

Basics

nmap 192.168.1.0/24          # host discovery + top 1000 ports
nmap -sn 192.168.1.0/24      # ping scan only, no ports
nmap -p- 10.0.0.5            # all 65535 TCP ports
nmap -sV -sC 10.0.0.5        # service versions + default scripts
nmap -O 10.0.0.5             # OS detection (needs root)

Speed and output

nmap -T4 --min-rate 1000 10.0.0.5
nmap -oA scan 10.0.0.5       # save in three formats