The known-unicast-suppression command sets the maximum traffic volume of known unicast packets that can pass through an interface.
The undo known-unicast-suppression allows all known unicast packets to pass.
By default, known unicast packets are not suppressed.
S5720-HI, S5735-L, S5735S-L, S5735S-L-M, S5735-S, S5735-S-I, and S5735S-S do not support this command.
known-unicast-suppression { percent-value | cir cir-value [ cbs cbs-value ] | packets packets-per-second }
undo known-unicast-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 that 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 Scenario
You can use the known-unicast-suppression command to set the threshold of known multicast traffic that an interface allows to pass through. When the known unicast traffic rate exceeds the rate limit, the system discards excess known unicast packets to control the traffic volume in 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.