21-3
Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
OL-10101-02
Chapter 21 Configuring Port-Based Traffic Control
Configuring Storm Control
To disable storm control, use the no storm-control broadcast level, the no storm-control multicast
level, or the no storm-control unicast level interface configuration command.
This example shows how to enable broadcast address storm control on a port to a level of 20 percent.
When the broadcast traffic exceeds the configured level of 20 percent of the available bandwidth of the
port within the traffic-storm-control interval, the switch drops all broadcast traffic until the end of the
traffic-storm-control interval:
Switch# configure terminal
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# storm-control broadcast level 20
If you configure the action to be taken when a packet storm is detected as shutdown (the port is
error-disabled during a storm), 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).
Step 3 storm-control {broadcast | multicast |
unicast} level {level [level-low] | pps pps
[pps-low]}
Configure broadcast, multicast, or unicast storm control.
The keywords have these meanings:
• For level, specify the rising threshold level for broadcast,
multicast, or unicast traffic as a percentage of the bandwidth.
The storm control action occurs when traffic utilization reaches
this level.
• (Optional) For level-low, specify the falling threshold level as a
percentage of the bandwidth. This value must be less than the
rising supression value.The normal transmission restarts (if the
action is filtering) when traffic drops below this level.
• For pps pps, specify the rising threshold level for broadcast,
multicast, or unicast traffic in packets per second. The storm
control action occurs when traffic reaches this level. This option
is supported only on non-LRE Catalyst 2950 switches running
Cisco IOS Release 12.1(14)EA1 or later.
• (Optional) For pps-low, specify the falling threshold level in
packets per second that can be less than or equal to the rising
threshold level. The normal transmission restarts (if the action is
filtering) when traffic drops below this level. This option is
supported only on non-LRE Catalyst 2950 switches.
For pps and pps-low, the range is from 0 to 4294967295.
Step 4 storm-control action {shutdown | trap}Specify the action to be taken when a storm is detected. The default
is to filter out the traffic and not to send traps.
• Select the shutdown keyword to error-disable the port during a
storm.
• Select the trap keyword to generate an SNMP trap when a storm
is detected.
Step 5 end Return to privileged EXEC mode.
Step 6 show storm-control [interface] [{broadcast
| history | multicast | unicast}]
Verify your entries.
Step 7 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose