Final answer:
A MAC flooding attack occurs when a switch's MAC table is overwhelmed with forged frames, causing the switch to broadcast packets to all ports, leading to security vulnerabilities.
Step-by-step explanation:
When an attacker generates a plethora of forged frames with the intention of overwhelming the switch's MAC table, this is known as a MAC flooding attack. The primary goal of this attack is to flood the switch's memory with fake MAC addresses. As a result, the switch gets confused and starts acting like a hub, broadcasting packets to all ports because it can't distinguish which port to send the data through. This can lead to potential security breaches as an attacker might be able to capture sensitive data intended for other recipients on the network.