arp-scan
arp-scan finds devices on the local Ethernet segment by sending ARP requests and listing MAC and IP addresses.
Legal & ethical use. Use this tool only on systems, networks and data that you own or have explicit written permission to test. Unauthorised access or scanning can break computer-misuse laws (for example Pakistan's Prevention of Electronic Crimes Act, 2016, and equivalents elsewhere). Practise in your own lab or in authorised environments such as CTFs.
What it is used for
- Inventory devices on your home or lab LAN
- Find unknown devices plugged into a network you manage
Key features
- ARP-based discovery of all local hosts
- MAC vendor lookup
- Works even when hosts block ping
Installation
Available as a package on most Linux distributions (for example `sudo apt install arp-scan`).
Beginner usage guide
Run it with --localnet on the interface connected to your lab network; each line is a device with its MAC address and vendor.
Example commands
Run these only against your own lab or authorised targets. Placeholder addresses such as 192.0.2.x are documentation ranges.
Discover local devices
sudo arp-scan --localnetSends ARP requests to every address on the local network and prints replies.
References
Source verification
Last reviewed: 2026-10-27
Links checked over HTTP: 2026-10-27 07:51 UTC — official: 200, docs: 200, repo: 200
Command flags checked against the real binary arp-scan (arp-scan 1.10.0) on 2026-10-27.