broadcast-suppression

Format

broadcast-suppression cir cir-value [ cbs cbs-value ] [ inbound | outbound ]

undo broadcast-suppression [ inbound | outbound ]

Parameters

Parameter	Description	Value
cbs cbs-value	Specifies the committed burst size (CBS), that is, the depth of the first token bucket (which is presumed to be the C bucket).	The value ranges from 0 bytes to 4,294,967,295 bytes. The recommended value is 187 times the cir-value. The default value varies with the value of cir-value: cbs-value = cir-value 187. If cir-value<100000 kbit/s, the default value of cbs-value equals cir-value 187 (in bytes). If cir-value >=100000 kbit/s, the default value of cbs-value equals 100000*187 (in bytes).
inbound	Specifies the inbound direction.	-
outbound	Specifies the outbound direction.	-
cir cir-value	Specifies the committed information rate (CIR).	The value is an integer that ranges from 0 kbit/s to 4,294,967,295 kbit/s.

Views

QoS profile view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
qos	write

Usage Guidelines

Usage Scenario

When broadcast packets grow on a network, resources consumed by broadcast packets increase accordingly, affecting running services on the network.

To prevent broadcast storms, you can run the broadcast-suppression command to configure a threshold for broadcast packets in a QoS profile. When the number of broadcast packets exceeds the configured threshold, the system drops excess broadcast packets so that the broadcast traffic volume can be restricted within a proper range.

Precautions

The broadcast suppression in the QoS profile does not take effected in VLL scenario.

To implement precise traffic suppression, you should specify a value for the CBS that is over 10 times the packet length.

If member interfaces of a trunk interface reside on different forwarding or traffic management modules, the effective CIR or PIR for CAR or user-queue can be a multiple of the configured one.

Direction-oriented and directionless broadcast suppression cannot be configured at the same time. If direction-oriented broadcast suppression is configured on an interface, the configuration takes effect only when the direction to which the QoS profile applies is the same as the direction configured for broadcast suppression.

Example

# Configure broadcast suppression in a QoS profile named test. Set the CIR of packets to 38400 kbit/s. (With this setting, if the traffic rate is equal to or smaller than 38400 kbit/s, packets are sent normally. Otherwise, packets are discarded.)

<HUAWEI> system-view
[~HUAWEI] qos-profile test
[*HUAWEI-qos-profile-test] broadcast-suppression cir 38400