Cisco Catalyst 3550 Command Reference Manual page 594

storm-control
Command History Release
12.1(8)EA1
12.1(22)EA1
12.2(25)SE
Usage Guidelines Storm control is supported only on physical interfaces; it is not supported on EtherChannel port
channels, even though it is available in the CLI.
The storm-control suppression level can be entered as a percentage of total bandwidth or as a rate in
packets per second at which traffic is received.
When specified as a percentage of total bandwidth, a suppression value of 100 percent means that no
limit is placed on the specified traffic type. A value of level 0 0 means that all broadcast, multicast, or
unicast traffic on that port is blocked. Storm control 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 traps.
If a multicast storm control suppression level is exceeded on a switch, all traffic (multicast, unicast, and
Note
broadcast) is blocked until the multicast traffic rate drops below the threshold. Only spanning-tree
packets are passed. If the broadcast or the unicast storm control suppression level is exceeded, only that
type of traffic is blocked until the rate drops below the threshold.
The trap and shutdown options are independent of each other.
If you configure the action to be taken as shutdown (the port is error-disabled during a storm) when a
packet storm is detected, you must use the no shutdown interface configuration command to bring the
interface out of this state. If you do not specify the shutdown action, specify the action as trap (the
switch generates a trap when a storm is detected).
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.
Note Storm control is supported on physical interfaces. You can also configure storm control on an
EtherChannel. When storm control is configured on an EtherChannel, the storm control settings
propagate to the EtherChannel physical interfaces.
When a broadcast storm occurs and the action is to filter traffic, the switch blocks only broadcast traffic.
For more information, see the software configuration guide for this release.
Examples This example shows how to enable broadcast storm control with a 75.5-percent rising suppression level:
Switch(config-if)# storm-control broadcast level 75.5
Catalyst 3550 Multilayer Switch Command Reference
2-568
Modification
This command was introduced. It replaces the switchport broadcast,
switchport multicast, and switchport unicast interface configuration
commands.
The level level [.level] option was replaced with the level level [level-low]
option. The pps pps pps-low options were added.
The pps-low option was made an optional parameter, and the range was
changed. The action {shutdown | trap} keywords were added.
Chapter 2 Catalyst 3550 Switch Cisco IOS Commands
OL-8566-01