Final answer:
ARP spoofing/poisoning is a cyber attack where false ARP messages link an attacker's MAC address to an IP address of a target, intercepting or altering data sent to that IP. It is a significant threat on LANs and can be part of various cyberattacks.
Step-by-step explanation:
ARP spoofing, also known as ARP poisoning, is a type of cyber attack carried out over a Local Area Network (LAN) that involves sending falsified ARP (Address Resolution Protocol) messages over the network. The attacker's goal is to link their MAC address with the IP address of another host, such as the default gateway, causing any traffic meant for that IP address to be wrongly sent to the attacker instead.
This allows the attacker to intercept, modify, or even stop data-in-transit. ARP spoofing is used in a variety of cyber attacks, including man-in-the-middle, denial of service, and session hijacking. To protect against ARP spoofing, there are security measures such as the use of VPNs, packet filtering, and turning on DHCP snooping and dynamic ARP inspection on switches.