Which type of Layer 2 attack causes a switch to flood all incoming traffic to all ports?

A.
MAC spoofing attack

B.
CAM overflow attack

C.
VLAN hopping attack

D.
STP attack

Explanation:
http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/white_paper_c11_603836.htm
lSummary
The MAC Address Overflow attack is effective if the proper mitigation techniques are not in place
on the Cisco Catalyst 6500 series switch. By using publicly (free) and available Layer 2 attack
tools found on the Internet, anyone who understands how to setup and run these tools could
potentially launch an attack on your network.
MAC address monitoring is a feature present on Cisco Catalyst 6500 Series switches. This feature
helps mitigate MAC address flooding and other CAM overflow attacks by limiting the total number
of MAC addresses learned by the switch on per-port or per-VLAN basis. With MAC Address
Monitoring, a maximum threshold for the total number of MAC addresses can be configured and
enforced on a per-port and/or per-VLAN basis.
MAC address monitoring in Cisco IOS Software allows the definition of a single upper (maximum)
threshold. In addition, the number of MAC addresses learned can only be monitored on a per-port
or per-VLAN basis, and not a per-port-per-VLAN. By default, MAC address monitoring is disabled
in Cisco IOS Software. However, the maximum threshold for all ports and VLANs is configured to
500 MAC address entries, and when the threshold is exceeded the system is set to generate a
system message along with a syslog trap. These default values take effect only when MAC
address monitoring is enabled. The system can be configured to notify or disable the port or VLAN
every time the number of learned MAC addresses exceeds the predefined threshold. In our test,
we used the “mac-address-table limit” command on the access layer port interface to configure the
MAC address monitoring feature.