nmap

🔍 Tool Tutorial for Beginners

📌 Goal

Teach beginners what Nmap is, why it’s used, and how to perform safe, basic network scans while building a foundation for ethical hacking, blue-team monitoring, and vulnerability assessment.

🧠 Prerequisites

  • Basic understanding of:
    • IP addresses
    • Ports
    • TCP vs UDP (high level)
  • A legal target (own machine, lab, or permission granted ⚠️)

🧰 1: What Is Nmap?

  • Nmap stands for (Network Mapper)
  • Common use cases:
    • Network discovery
    • Port scanning
    • Service identification
    • Security assessments

⚖️ 2: Legal & Ethical Considerations

  • When scanning is legal vs illegal
  • Why permission matters
  • Safe lab environments:
    • Localhost
    • Home lab
    • Hack The Box / TryHackMe

💻 3: Nmap Commands

  • Verify installation: nmap –version
  • Scan targets can be:
    • Hostnames or IPs
    • Single IP or IP ranges
    • CIDR notation
  • Port Scanning:
    • State – nmap 192.168.1.1
    • Port – nmap -p 80 192.168.1.1
    • Port Range – nmap -p 1 -100 192.168.1.1
    • Service – nmap -sV 192.168.1.1
    • OS – nmap -O 192.168.1.1

There are many downloadable Nmap Cheat Sheets online. Find one you prefer, and begin to practice scanning.