Nmap Cheat Sheet: Complete Reference for Security Professionals

What is Nmap?

Nmap (Network Mapper) is a free, open-source tool for network discovery and security auditing. It is one of the most essential tools in any security professional's arsenal.

Basic Scanning

# Scan a single host
nmap 192.168.1.1

# Scan a subnet
nmap 192.168.1.0/24

# Scan specific ports
nmap -p 80,443,8080 192.168.1.1

# Scan all ports
nmap -p- 192.168.1.1

Service & Version Detection

# Detect services and versions
nmap -sV 192.168.1.1

# Aggressive scan
nmap -A 192.168.1.1

# OS detection
nmap -O 192.168.1.1

Stealth Scanning

# SYN scan (stealth)
nmap -sS 192.168.1.1

# UDP scan
nmap -sU 192.168.1.1