The broadcast-suppression command sets the maximum traffic rate of broadcast packets that can pass through an interface.
The undo broadcast-suppression command restores the default maximum traffic rate of broadcast packets that can pass through an interface.
By default, the rate of broadcast packets is suppressed by bandwidth percentage, and the percentage rate limit is 10%.
broadcast-suppression { percent-value | cir cir-value [ cbs cbs-value ] | packets packets-per-second }
undo broadcast-suppression
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:
|
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:
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:
NOTE:
|
Ethernet interface view, 40GE interface view, 100GE interface view, GE interface view, XGE interface view, 25GE interface view, MultiGE interface view, port group view
Usage Guidelines
The accumulating broadcast packets on the network occupy more and more network resources. This affects normal operation of services on the network.
To prevent broadcast storms, you can use the broadcast-suppression command to set the threshold of broadcast traffic that an interface allows to pass through. When the broadcast traffic rate reaches the rate limit, the system discards excess broadcast packets to control the traffic rate in a proper range.
Precautions
If the rate limit in bit/s is set for a type of packets on an interface, the rate limit in pps cannot be set for other types of packets on the same interface. In a similar manner, if the rate limit in pps is set for a type of packets on an interface, the rate limit in bit/s cannot be set for other types of packets on the same interface.
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.