Which Attack Overflows a Switch's CAM Table?

Why the Answer Is Correct

MAC flooding is a Layer 2 attack where an attacker sends a large number of fake Media Access Control (MAC) addresses to fill the switch's Content-Addressable Memory (CAM) table. Once the CAM table is full, the switch can no longer learn or store legitimate MAC addresses, so it falls back to flooding unknown unicast frames out all ports, behaving like a hub. This allows the attacker to sniff traffic that was not originally destined to their port. Comments from users note that "CAM is within the MAC...CAM is MAC backwards" as a memory aid, and another comment explicitly states that MAC flooding targets the switch's CAM table by overwhelming it with fake MAC addresses.

Why the Other Options Are Wrong

ARP spoofing is incorrect because it involves sending forged Address Resolution Protocol (ARP) messages to poison the ARP cache of hosts, redirecting traffic at the IP-to-MAC mapping level, not by overflowing switch memory. Evil twin is incorrect because it is a wireless attack where an attacker sets up a rogue access point with a legitimate-looking SSID to steal credentials or intercept Wi-Fi traffic. DNS poisoning is incorrect because it corrupts DNS resolver caches to redirect domain names to malicious IP addresses, affecting name resolution rather than switch forwarding tables. All three options are distinct attack types that do not describe the act of overflowing a switch's CAM table.

Community Comment Notes

Community discussion is unanimous in selecting C, MAC flooding. One commenter suggests a mnemonic: "CAM is within the MAC....CAM is MAC backwards." Another commenter provides a direct definition: MAC flooding is a network attack that specifically targets a switch's Content-Addressable Memory (CAM) table by overwhelming it with fake MAC addresses. A third commenter explains the consequence: the switch fails and behaves like a hub, enabling the attacker to capture sensitive data through traffic interception. These comments reinforce the textbook definition and align with CompTIA Network+ objectives.