Leaflet

OL-11615-01

if you need to control the volume of BPDUs or other Layer 2 PDUs. Note that the hardware-based rate

limiters must be used cautiously, they control traffic globally and can also have potential side effects on

the Layer 2 connectivity. Refer to

Hardware-Based Rate Limiters on Supervisors 32 and 720, page 72

for more information.

Traffic storm control is disabled by default.

To configure traffic storm control on a Catalyst 6500 Series switch running Cisco IOS, perform the

following steps:

Step 1 At the interface level enable broadcast traffic storm control, configure the traffic storm control level and

apply the traffic storm control level to all traffic storm control modes enabled on the interface. Use the

storm-control broadcast level interface command:

Router(config)# interface {{

type slot/port

| {port-channel

number

}}

Router(config-if)# storm-control broadcast level level[.level]

Step 2 Enable multicast traffic storm control on the interface, configure the traffic storm control level, and apply

the traffic storm control level to all traffic storm control modes enabled on the interface. Use the

storm-control multicast level interface command:

Router(config-if)# storm-control multicast level level[.level]

Step 3 Enable unicast traffic storm control on the interface, configure the traffic storm control level, and apply

the traffic storm control level to all traffic storm control modes enabled on the interface. Use the

storm-control unicast level interface command:

Router(config-if)# storm-control unicast level level[.level]

This example shows how to enable multicast traffic storm control on Gigabit Ethernet interface 3/16 and

how to configure the traffic storm control level at 70.5 percent. This configuration applies the traffic

storm control level to all traffic storm control modes enabled on Gigabit Ethernet interface 3/16:

Router# configure terminal

Router(config)# interface gigabitethernet 3/16

Router(config-if)# storm-control multicast level 70.5

Router(config-if)# end

For more information on Broadcast Suppression on the Catalyst 6500 running Cisco IOS, refer to the

following URL:

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/122sx/swcg/storm.htm

Catalyst 4500 Port-Based Traffic Control (Cisco IOS)

On Catalyst 4500 Series switches, the traffic storm control feature is called port-based traffic control.

This feature is available only on Cisco IOS software for Catalyst 4500 Series switches, and it primarily

supports broadcast suppression. Multicast suppression is available on WS-X4516 supervisor engines and

newer hardware.

Broadcast suppression on the Catalyst 4500 Series switches is implemented in hardware. The

suppression circuitry monitors packets passing from a LAN interface to the switching bus. If the packet

destination address is broadcast, then the broadcast suppression circuitry tracks the current count of

broadcasts within the one-second interval, and when a threshold is reached, it filters out subsequent

broadcast packets.