Cheatsheets

Nmap Security Tool Cheatsheet

by n8n admin

🤖 AI Prompts Cheatsheet

Daniel Osei — AI-Assisted Security Engineer

What is Nmap?

Nmap (Network Mapper) is a powerful open-source tool used for network discovery and security auditing. It allows security professionals to discover hosts and services on a network, thus providing a comprehensive view of a target’s surface area.

Installation

Nmap can be installed on various operating systems including Linux, Windows, and macOS. To install on different platforms:

  • On Debian/Ubuntu: sudo apt install nmap
  • On Fedora: sudo dnf install nmap
  • On macOS: brew install nmap
  • On Windows: Download the installer from the Nmap official website.

Basic Syntax

The general syntax for Nmap is:

nmap [options] [targets]

Scanning

Host Discovery

Identify active hosts on a network:

nmap -sn 192.168.1.0/24

Service Version Detection

Detect services and their versions running on target hosts:

nmap -sV 192.168.1.1

Operating System Detection

Identify the operating system of a target:

nmap -O 192.168.1.1

Exploitation

TCP Connect Scan

A full TCP connection scan:

nmap -sT 192.168.1.1

Stealth Syn Scan

A stealthier alternative to TCP connect scan:

nmap -sS 192.168.1.1

Analysis

Script Scanning

Using Nmap’s scripting engine to execute scripts:

nmap --script=http-vuln* 192.168.1.1

Reporting

Output Options

Generate output in various formats:

Flag Description
-oN Normal output
-oX XML output
-oG Grepable output 
nmap -oN output.txt 192.168.1.1

Pro Tips

  • Use -Pn to skip host discovery if you know the target is up, speeding up scans.
  • Combine scripts with --script-args for tailored scans.
  • Save scan profiles for repeated assessments with the -iL option.

Real-World Examples

Example 1: Scanning a specific range of IPs for open ports and service versions:

nmap -p 1-65535 -sS -sV 192.168.1.0/24

Example 2: Saving results in XML format for further analysis:

nmap -oX scan_results.xml 192.168.1.10

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