Module 1: BSWJ: Arp-Scan
Using the Arp-Scan Network Discovery Tool
The Arp-scan network discovery tool is designed to map physical (MAC) addresses to logical (IP) addresses. The Arp-scan tool uses the Address Resolution Protocol (ARP) to identify all active network assets that may not typically be recognized by network scanning devices.
The main purpose of the Arp-scan tool is to discover all the active devices within an IPv4 range, even those that are protected by a firewall that is created to hide the device’s presence. Whether using WIFI or ethernet, the IPv4 devices on your local-area network (LAN) are required to respond or they are unable to communicate.
The Arp-scan network discovery tool is an essential piece that every IT and cybersecurity professional should know and understand. Every ethical hacker must have a strong understanding of fundamental networking protocols, of which ARP is at the top of the list. Without this protocol, LANs would no longer function, which means that users must be competent when checking the contents of their ARP cache and also have a solid understanding of performing ARP scanning.
Why Use the Arp-Scan Network Discovery Tool?
Organizations need to have technology professionals who understand the Address Resolution Protocol and the Arp-scan tool. A criminal hacker can easily take advantage of ARP messages and discover the IP and MAC addresses of network devices – without detection. Alternatively, they may also actively scan the network with spoofed ARP requests.
The most obvious thing system administrators and criminal hackers have in common is the necessity of performing network reconnaissance. For both individuals, such reconnaissance has to be carried out as quickly and with as little impact to users as possible. Arp-scanning is a tool that allows users to find every network-connected device on a subnet.
The Arp-scan tool is extremely versatile, and it aids organizations in many ways. The most commonly cited benefits of using this network scanner are:
- It allows users to discover all the IPv4 network-connected devices.
- It can quickly identify and map IP addresses to MAC addresses.
- It will identify any duplicate IP addresses.
- It will isolate and locate rogue devices.
- It identifies devices by NIC vendor. For more information about the Arp-scan network discovery tool, and to learn to use it, check out our How to Use Arp-scan tutorial. The class is free, and it provides you with foundational information and the steps you need to take to use Arp-scan for network scanning.
- George Mcpherson
- Vikramajeet Khatri
(Disclaimer: Breaking Stuff with Joe is a Cybrary series that will be running indefinitely. You will not earn CEU/CPE hours by watching any individual 'Breaking Stuff with Joe' episode. However, you can still earn a certificate of completion for each episode completed.)