Filter
Top Products
38-2
Cisco ASR 901 Series Aggregation Services Router Software Configuration Guide
OL-23826-09
Chapter 38 Storm Control
Feature Overview
Prerequisites
• Cisco IOS Release 15.3(3)S or a later release that supports the Storm Control feature must be
installed previously on the Cisco ASR 901 Series Aggregation Services Router.
Restrictions
• The storm-control command is not recommended on an interface that is part of a port channel.
• Storm-control counters are not supported on port channel as the counters are based on physical
ports.
• Discarded counters are not displayed for port channel. You should check the port channel
member-ports for discarded counters.
• The current rate field is not supported for show commands in hardware based storm control.
• Supports only drop counters. Total broadcast received in storm control is not supported.
Feature Overview
A traffic storm occurs when huge amount of broadcast, multicast, or unknown unicast packets flood the
LAN, creating excessive traffic and degrading network performance. Errors in the protocol-stack
implementation or in the network configuration can also cause a storm. The mechanism to prevent and
control such events is known as storm control or broadcast suppression.
The Storm Control feature prevents switchports on a LAN from being disrupted by a broadcast,
multicast, or unknown unicast storm on one of the interfaces. This feature monitors incoming traffic
statistics over a time period and compares the measurement with a predefined suppression level
threshold. The threshold represents the percentage of the total available bandwidth of the port. If the
threshold of a traffic type is reached, the system takes the appropriate storm control action until the
incoming traffic falls below the threshold level.
Storm control also acts as a policer, and it drops only the storms that breaches the configured storm level.
This feature supports the following:
• Ethernet port: per port configuration for broadcast, multicast, and unknown unicast traffic.
• 10 GigabitEthernet interfaces.
• SNMP trap and SYSLOG messages: indicating storm control detection.
• Individual dropped packet counters: for broadcast, multicast, and unknown unicast flows.
• Error disable recovery feature with storm control shutdown action.
Configuring Storm Control
To configure Storm Control feature, complete the following steps:
Note This feature is disabled by default.