Specifications

CHAPTER
28-1
Cisco MWR 2941 Mobile Wireless Edge Router Release 3.5 Software Configuration Guide, Cisco IOS Release 15.1(3)MR
OL-26895-01
28
Configuring Traffic Storm Control
This chapter describes how to configure traffic storm control on the Cisco MWR 2941.
This chapter includes the following sections:
• Traffic Storm Control Overview, page 28-1
• Guidelines and Limitations, page 28-2
• Configuring Traffic Storm Control Support on the MWR 2941, page 28-3
• Monitoring and Maintaining Storm Control, page 28-6
Traffic Storm Control Overview
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 Cisco MWR 2941 Release 3.5 supports storm control using port
bandwidth level or rate of packets per second (PPS). Bandwidth-based traffic storm control level is a
percentage of the total available bandwidth of the port. PPS-based storm control is the maximum rate of
PPS 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.
The Cisco MWR 2941 supports independent broadcast storm control and dependent multicast/unicast
storm control. Therefore, the behavior below applies to traffic storm control support on the MWR 2941:
• If you enable broadcast traffic storm control, and broadcast traffic exceeds the level within a
1-second traffic storm control interval, traffic storm control drops all broadcast traffic on the
interface until the end of the traffic storm control interval.
• If you enable multicast traffic storm control, and multicast traffic exceeds the level within a 1-second
traffic storm control interval, traffic storm control drops all traffic (broadcast, multicast, and unicast)
on the interface until the end of the traffic storm control interval.