Cisco Systems 4500 Enabling Broadcast Storm Control

50-3
Software Configuration Guide—Release 15.0(2)SG
OL-23818-01
Chapter 50 Configuring Storm Control Enabling Broadcast Storm Control
Software-Based Storm Control Implementation
When storm control is enabled on an interface, the switch monitors packets received on the interface and
determines whether the packets are broadcast. The switch monitors the number of broadcast packets
received within a one-second time interval. When the interface threshold is met, all incoming data traffic
on the interface is dropped. This threshold is specified as a percentage of total available bandwidth that
can be used by broadcast traffic. If the lower threshold is specified, all data traffic is forwarded as soon
as the incoming traffic falls below that threshold.
Enabling Broadcast Storm Control
To enable storm control, perform this task:
Command Purpose
Step 1 Switch# configure terminal Enters global configuration mode.
Step 2 Switch(config)# interface interface-id Enters interface configuration mode and enter the port to configure.
Step 3 Switch(config-if)# storm-control
broadcast level [high level] [lower
level]
Configures broadcast storm control.
Specifies the upper threshold levels for broadcast traffic. The storm
control action occurs when traffic utilization reaches this level.
(Optional) Specifies the falling threshold level. The normal
transmission restarts (if the action is filtering) when traffic drops
below this level for interfaces that support software-based
suppression.
Note The lower level keyword does not apply to Supervisor
Engine 6E implementations.
Note For ports that perform hardware-based suppression, the
lower threshold is ignored.
Step 4 Switch(config-if)# storm-control action
{shutdown | trap}Specifies the action to be taken when a storm is detected.
The default is to filter out the broadcast traffic and not to send out
traps.
The shutdown keyword sets the port to error-disable state during a
storm. If the recover interval is not set, the port remains in shutdown
state.
Note The trap keyword generates an SNMP trap when a storm is
detected. This keyword is available but not supported in
Cisco IOS Release 12.1(19)EW.
Step 5 Switch(config-if)# exit Returns to configuration mode.
Step 6 Switch(config)# end Returns to privileged EXEC mode.
Step 7 Switch# show storm-control [interface]
broadcast Displays the number of packets suppressed.
Step 8 Switch# copy running-config
startup-config (Optional) Saves your entries in the configuration file.