Network Scanning Tools Setup Guide

Learn how to install and use nmap and arp-scan on your computer

Quick Navigation

Overview: Choosing Your Network Scanning Tool

Before you scan your network, you need to choose which tool to use. Here's a quick comparison:

Tool Best For Windows Linux
nmap Comprehensive scanning ✓ ✓
arp-scan Fast local scans Limited ✓
arp (built-in) View known devices ✓ ✓

Recommendation

Start with nmap — it works on all operating systems and is the most powerful. If you want faster results on Linux, add arp-scan after you're comfortable with nmap.

Install nmap on Windows

1Download nmap

  1. Go to https://nmap.org/download.html
  2. Click the Windows installer (usually named something like nmap-X.XX-setup.exe)
  3. Save the file to your computer

2Run the Installer

  1. Double-click the downloaded .exe file
  2. Click "I Agree" to accept the license agreement
  3. Follow the setup wizard, keeping defaults and clicking "Next"
  4. Click "Finish" when installation completes

3Verify Installation

Open Command Prompt and type:

nmap --version

You should see the nmap version number. If you see "command not found", restart your computer and try again.

4Run Your First Scan

nmap -sn 192.168.1.0/24

Replace 192.168.1.0/24 with your actual subnet. Results will show discovered hosts.

✓ Success! Copy the output and paste it into the Network Scanner to analyze your network.

Install nmap on Linux

1Update Package Manager

Open Terminal and run:

sudo apt update

2Install nmap

sudo apt install nmap

When prompted, type y and press Enter to confirm installation.

3Verify Installation

nmap --version

4Run Your First Scan

nmap -sn 192.168.1.0/24

Replace with your subnet address. Wait for results showing discovered hosts.

✓ Success! Copy the output and use the Network Scanner to analyze results.

How to Use These Tools

nmap: Ping Scan (Recommended)

nmap -sn 192.168.1.0/24
  • -sn = ping scan (no port scanning)
  • Shows all responding hosts on your network
  • Replace 192.168.1.0/24 with your subnet

Windows Built-in arp command

arp -a
  • Shows devices your computer already knows about
  • Not a full network scan, just cached entries
  • No installation needed!

Troubleshooting

Windows: "nmap not found"

Problem: Command Prompt doesn't recognize nmap
  • Restart your computer after installation
  • Check that nmap installed to C:\Program Files\Nmap\

Linux: "Permission denied"

Problem: Need root access for network scanning
  • Use sudo before the command

No hosts detected

Problem: Scan completes but shows no devices
  • Verify your subnet is correct
  • Check you're on the same network as the devices
  • Some firewalls may block ICMP ping requests

Next Steps

  1. Install nmap using the guide above for your operating system
  2. Run your first scan: nmap -sn 192.168.1.0/24 (replace with your subnet)
  3. Copy the results (all the text showing discovered hosts)
  4. Go to Network Scanner
  5. Paste your scan results and click "Analyze Network"
✓ Now you can: Identify unused IP addresses, find unexpected devices on your network, and troubleshoot connectivity issues!