ARP cache poisoning - Computer Definition
A method of intercepting packets in a TCP/IP network by sending a false address resolution protocol (ARP) message into the network. In order to accomplish this, the attacker must have access to the local network. The false ARP message generally redirects traffic to the perpetrator's computer, which is used to view or modify the network packets in some manner. See ARP, ARP cache and man-in-the-middle attack.