multicast-suppression (interface view)

Function

The multicast-suppression command sets the maximum traffic volume of unknown multicast packets that can pass through an interface.

The undo multicast-suppression allows all unknown multicast packets to pass.

By default, unknown multicast packets are not suppressed.

Format

multicast-suppression { percent-value | cir cir-value [ cbs cbs-value ] | packets packets-per-second }

undo multicast-suppression

Parameters

Parameter	Description	Value
percent-value	Specifies the percentage of bandwidth occupied by broadcast packets on an interface. If loopback detection is enabled on an interface, the interface rate is set by user. If loopback detection is not enabled on an interface, the interface rate is automatically negotiated. You can run the display this interface command in the interface view to check the interface rate (value of the Speed field).	The value is an integer and the value range is as follows: 40GE interface: 0 to 100 on the S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-HI, S6730-H, S6730S-H, S6730-S, and S6730S-S Other interfaces: 0 to 100
cir cir-value	Specifies the committed information rate (CIR), which is the allowed rate at which traffic can pass through. NOTE: Traffic suppression based on cir is more precise than that based on packets. To specify the cir parameter, ensure that the traffic suppression mode set in the system view is bits.	The value is an integer, in kbit/s. The value range is as follows: Ethernet interface: 0 to 100000 GE interface: 0 or 16 to 1000000 for the S5735-L, S5735S-L, S5735S-L-M, S5735-S, S5735-S-I, and S5735S-S, 0 to 1000000 for the others XGE interface: 0 or 16 to 10000000 for the S5735-L, S5735S-L, S5735S-L-M, S5735-S, S5735-S-I, and S5735S-S, 0 to 10000000 for the others 25GE interface: 0 to 25000000 MultiGE interface: 0 to X, X indicates the negotiated bandwidth 40GE interface: 0 to 40000000 100GE interface: 0 to 100000000 Port group: 0 to 100000000 NOTE: When an interface is configured with an optical module, the value range is determined by the rate of the optical module. For example, when an XGE interface is configured with a GE optical module, the value range is 0 to 1000000.
cbs cbs-value	Specifies the committed burst size (CBS), which is the maximum size of traffic that can pass through.	The value is an integer. For the S5735-L, S5735S-L, S5735S-L-M, S5735-S, S5735-S-I, and S5735S-S, the value ranges from 10000 to 65535; for the others, the value ranges from 10000 to 4294967295, in bytes. By default, the CBS value is 188 times the CIR value.
packets packets-per-second	Specifies the number of packets transmitted per second. NOTE: To specify the packets parameter, ensure that the traffic suppression mode set in the system view is packets.	The value is an integer and the value range is as follows: Ethernet interface: 0 to 148810 GE interface: 0 to 1488100 XGE interface: 0 to 14881000 MultiGE interface: 0 to X. X indicates the negotiated bandwidth 25GE interface: 0 to 37202500 40GE interface: 0 to 59524000 100GE interface: 0 to 148810000 Port group: 0 to 148810000 NOTE: For S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-HI, S6730-H, S6730S-H, S6730-S, and S6730S-S, if the configured value is less than 24, traffic suppression is performed based on 24. If the configured value is greater than or equal to 24, traffic suppression is performed based on the configured value. When an interface is configured with an optical module, the value range is determined by the rate of the optical module. For example, when an XGE interface is configured with a GE optical module, the value range is 0 to 1488100.

Views

Ethernet interface view, 40GE interface view, 100GE interface view, GE interface view, XGE interface view, 25GE interface view, MultiGE interface view, port group view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

When an increasing number of unknown multicast packets are transmitted on a network, more network resources are occupied and services are affected.

To prevent broadcast storms, you can use the multicast-suppression command to set the threshold of unknown multicast traffic that an interface allows to pass through. When the unknown multicast traffic volume exceeds the threshold, the system discards the excess unknown multicast packets to control the traffic volume of unknown multicast packets to a proper range.

Precautions

Setting the bandwidth percentage is the same as setting the rate limit in pps. Take an interface of 1 Gbit/s as an example. If the bandwidth percentage is set to 50%, the device converts the bandwidth percentage to rate limit in pps as follows: (1000 x (50/100) x 1000 x 1000)/(84 x 8). In the preceding formula, 84 is the average length of packets (including the 60-byte packet body, 20-byte frame spacing, and 4-byte check information), and 8 is the number of bits in a byte.

If a packet rate limit is configured for a type of packets on an interface, the percentage rate limit for other types of packets is converted into the packet rate limit.

Example

# Set the maximum unknown multicast packet rate to 100000 pps on GE0/0/1.

<HUAWEI> system-view
[HUAWEI] interface gigabitethernet 0/0/1
[HUAWEI-GigabitEthernet0/0/1] multicast-suppression packets 100000