Which two Catalyst 6500 features can be used to limit excessive traffic during spanning-tree loop conditions?

In Layer 2 topologies, spanning-tree failures can cause loops in the network. These unblocked
loops can cause network failures because of excessive traffic. Which two Catalyst 6500 features
can be used to limit excessive traffic during spanning-tree loop conditions? (Choose two.)

A.
Loop guard

B.
Storm control

C.
Storm suppression

D.
Broadcast suppression

E.
BPDU guard

Explanation:
Traffic Storm Control
A traffic storm occurs when packets flood the LAN, creating excessive traffic and degrading
network performance. The traffic storm control feature prevents LAN ports from being disrupted by

a broadcast, multicast, or unicast traffic storm on physical interfaces.
Traffic storm control (also called traffic suppression) monitors incoming traffic levels over a 1-
second traffic storm control interval and, during the interval, compares the traffic level with the
traffic storm control level that you configure. The traffic storm control level is a percentage of the
total available bandwidth of the port. Each port has a single traffic storm control level that is used
for all types of traffic (broadcast, multicast, and unicast).
Traffic storm control monitors the level of each traffic type for which you enable traffic storm
control in 1-second traffic storm control intervals. Within an interval, when the ingress traffic for
which traffic storm control is enabled reaches the traffic storm control level that is configured on
the port, traffic storm control drops the traffic until the traffic storm control interval ends.
Broadcast suppression Broadcast suppression prevents the switched ports on a LAN from being
disrupted by a broadcast storm on one of the ports. A LAN broadcast storm occurs when the
broadcast or multicast packets flood the LAN, creating excessive traffic and degrading the network
performance. Errors in the protocol-stack implementation or in the network configuration can
cause a broadcast storm.
Broadcast suppression uses filtering that measures the broadcast activity on a LAN over a time
period (15264 nsec to ~1 sec) that varies based on the type of line card and speed setting on the
port, and compares the measurement with a predefined threshold. If the threshold is reached,
further broadcast activity is suppressed for the duration of a specified time period. Broadcast
suppression is disabled by default.

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SXF/native/configuration/guid
e/storm.html\
http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/catos/8.x/configuration/guide/bcastsu
p.html