car share
Function
The car share command configures aggregated CAR in a traffic behavior.
The undo car share command cancels aggregated CAR in a traffic behavior.
By default, aggregated CAR is not configured in a traffic behavior.
Only the S5720-EI, 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 support this command.
Parameters
Parameter |
Description |
Value |
|---|---|---|
car-name |
Specifies the name of a CAR profile. |
The value must the name of an existing CAR profile. |
Usage Guidelines
Usage Scenario
When multiple traffic classifiers are defined in a traffic policy and traffic behaviors associated with the traffic classifiers define CAR (using the car cir command) and aggregated CAR, the system limits the rates of flows using the configured CAR, aggregates the flows, and limits the rate of the aggregated traffic using the aggregated CAR in sequence. This process is called hierarchical traffic policing.
Hierarchical traffic policing multiplexes traffic statistics and controls services in a fine-granular manner. For example, hierarchical traffic policing limits the service traffic of level-1 and level-2 users or traffic of level-1 and level-2 user groups.
Prerequisites
A QoS CAR profile has been configured using the qos car command.
Precautions
The traffic policy defining the aggregated CAR action can only be used in the inbound direction.
After aggregated CAR is configured, all the rules in the traffic classifiers bound to the same traffic behavior share the CAR index. The system aggregates all the flows matching these traffic classifiers and uses CAR to limit the rate of the flows. If the traffic classifiers define both Layer 2 and Layer 3 information, the aggregated CAR configuration is invalid.
A traffic policy limits the traffic rate using the aggregated CAR only in the current applied object. For example, when the traffic policy p1 defining the aggregated CAR is applied to interface1 and interface2, the aggregated CAR applies to traffic on interface1 and interface2 respectively, without affecting each other.
On the S5720-EI, if the sum of CIR values of each aggregated flow is larger than the specified CIR value for aggregated CAR in configured traffic policing, the system first guarantees the sum of CIR values of each flow. As a result, traffic exceeds the CIR value for aggregated CAR. 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, the system polices aggregated flows based on the CIR value for aggregated CAR. On the S5720-EI, to ensure that traffic is policed based on the CIR value for aggregated CAR, the CIR value for aggregated CAR must be larger than the sum of CIR values of each aggregated flow.