ARP Network Scanner

This Python script uses Scapy to perform a simple ARP scan across a given subnet, allowing you to discover active devices (IP ↔ MAC addresses) on the local network. It supports both Windows and Linux environments, with small differences between versions.

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⚙️ Features

• Scans a specified subnet using ARP requests.
• Shows IP and MAC addresses of discovered devices.
• Optional verbose output.
• Allows saving results to a text file.
• Compatible with both Windows and Linux.

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🧩 Requirements

Common

• Python 3.8+
• Scapy library

To install Scapy:

pip install scapy

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🪟 For Windows Users

Windows does not require root privileges but may need Administrator access to send raw packets.

Run Example:

python script_windows.py -i Ethernet -s 192.168.1.0/24 -t 3 -v -o results.txt

Available Options:

Option	Description
-i [iface]	Specify the network interface (e.g., Ethernet, Wi-Fi)
-s [subnet]	Target subnet (e.g., 192.168.1.0/24)
-t [timeout]	Timeout in seconds (default: 2)
-v	Enable verbose output
-o [file]	Save results to a file
-h, --help	Show help message

Example Output:

192.168.1.1 -> 74:D4:35:AB:12:EF
192.168.1.4 -> 58:D0:6E:22:AA:34

If -o is used, results are saved to the specified file.

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🐧 For Linux Users

Linux requires root privileges to send layer 2 packets.

Run Example:

sudo python3 script_linux.py -i eth0 -s 192.168.1.0/24 -t 3 -v -o scan.txt

Important:

If you do not run it as root, the script will exit with:

please run as root

Options:

Same as Windows version:

• -i [iface] → Interface name (e.g., eth0, wlan0)
• -s [subnet] → Subnet to scan
• -t [timeout] → Timeout value
• -v → Verbose mode
• -o [file] → Output file
• -h, --help → Help

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🧠 Notes

• The script uses srp() (send and receive packets at layer 2) — ideal for local network discovery.
• Works only on LAN networks (not over the internet).
• The Linux version performs a root check using os.geteuid() and enforces interface selection with -i.
• The Windows version doesn’t enforce root but allows scanning with srp() directly.

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🧾 Example Scan Result

When scanning 192.168.1.0/24, typical output:

192.168.1.1 -> 3C:7C:3F:90:12:89
192.168.1.5 -> 20:47:47:19:02:AA
192.168.1.10 -> 5C:D0:6E:55:AF:33

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📄 Output File Example (results.txt)

192.168.1.1 -> 3C:7C:3F:90:12:89
192.168.1.5 -> 20:47:47:19:02:AA
192.168.1.10 -> 5C:D0:6E:55:AF:33

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⚠️ Troubleshooting

• “Scapy not found” → Run pip install scapy
• “please run as root” (Linux) → Use sudo
• No output → Check your interface (-i) and subnet correctness.
• PermissionError (Windows) → Run terminal as Administrator.

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🧑‍💻 NullSpecter404

Created for educational and ethical network testing using Scapy. Do not use this tool on networks you don’t own or have permission to scan.