Cisco Catalyst 2950 Command Reference Manual page 313

Chapter 2 Cisco IOS Commands
Usage Guidelines
Use the storm-control command to enable or disable broadcast, multicast, or unicast storm control on
a port. After a port is disabled during a storm, use the no shutdown interface configuration command to
enable the port.
The suppression levels are entered as a percentage of total bandwidth. A suppression value of
100 percent means that no limit is placed on the specified traffic type. This feature is enabled only when
the rising suppression level is less than 100 percent. If no other storm-control configuration is specified,
the default action is to filter the traffic causing the storm and to send no SNMP trap.
When a storm occurs and the action is to filter traffic, if the falling suppression level is not specified, the
switch blocks all traffic until the traffic rate drops below the rising suppression level. If the falling
suppression level is specified, the switch blocks traffic until the traffic rate drops below this level.
When a multicast or unicast storm occurs and the action is to filter traffic, the switch blocks all traffic
(broadcast, multicast, and unicast traffic) and sends only Spanning Tree Protocol (STP) packets.
When a broadcast storm occurs and the action is to filter traffic, the switch blocks only broadcast traffic.
The trap and shutdown options are independent of each other.
Examples
This example shows how to enable broadcast storm control on a port with a 75.67 percent rising
suppression level:
Switch(config-if)# storm-control broadcast level 75.67
This example shows how to enable multicast storm control on a port with a 87 percent rising suppression
level and a 65 percent falling suppression level:
Switch(config-if)# storm-control multicast level 87 65
This example shows how to enable the shutdown action on a port:
Switch(config-if)# storm-control action shutdown
This example shows how to enable the trap action on a port:
Switch(config-if)# storm-control action trap
This example shows how to disable the shutdown action on a port:
Switch(config-if)# no storm-control action shutdown
You can verify your settings by entering the show storm-control privileged EXEC command.
Related Commands Command
show storm-control
78-11381-05
Description
Displays the packet-storm control information.
Catalyst 2950 Desktop Switch Command Reference
storm-control
2-289