Local area networks (LANs) are often the target of cyber attacks. If your business has a LAN, a hacker may attempt to breach or disrupt it. A LAN is simply a collection of interconnected devices in close proximity to each other. Wireless networks, for instance, are typically classified as LANs. For a secure LAN, you need to safeguard it from the Address Resolution Protocol (ARP) spoofing.

What Is ARP Spoofing?

Also known as ARP poisoning, ARP spoofing is a cyber attack that leverages fake ARP packets over a LAN. LANs support ARP packets. ARP, of course, is the protocol that links Internet Protocol (IP) addresses to Media Access Control (MAC) addresses. ARP packets essentially allow devices to communicate with each other. If a device wants to connect to another device, it will send an ARP packet.

While most ARP packets are legitimate, some of them may be fake. ARP spoofing revolves around the use of fake or “spoofed” ARP packets. The fake ARP packets don’t contain accurate data about the device from which they were sent. Rather, they contain falsified data in an effort to trick the LAN.

The Impact of ARP Spoofing

Hackers typically use ARP spoofing to steal data. It allows them to trick devices on a LAN into sending them sensitive data. If you exchange sensitive data over a LAN, you should beware of ARP spoofing. If your LAN is targeted with ARP spoofing, it could reveal sensitive data to a hacker.

During an ARP spoofing attack, a hacker will send a fake ARP packet to a LAN. This fake ARP packet will result in the LAN matching the hacker’s MAC address to the IP address of a legitimate device. As a result, data that’s meant for the legitimate device will be sent to the hacker’s device.

How to Protect Against ARP Spoofing

You can protect against ARP spoofing by using a packet-filtering firewall. Packet-filtering firewalls work by checking the contents of packets. With ARP spoofing, falsified packets are used, meaning they are fake. A packet-filtering firewall can catch and reject these fake packets so that they don’t lead to ARP spoofing.

You can also protect against ARP spoofing by using an encrypted protocol for your LAN. There are several encryption protocols that are available for LANs and other networks. Secure Shell (SSH), for instance, is an encrypted protocol. Another encryption protocol is HyperText Transfer Protocol Secure (HTTPS).