CloudEngine S5700 V600R022C01 Command Reference
Interface-based Rate Limiting Configuration Commands
qos lr(Management interface view)
Function
The qos lr pps command sets the rate limit on the management interface.
The undo qos lr pps command restores the default rate limit on the management interface.
By default, the rate limit on the management interface is 3000 pps.
This command is supported only on the S6730-H-V2 and S5732-H-V2.
Parameters
| Parameter | Description | Value |
|---|---|---|
| pps packets |
Specifies the maximum number of packets that are allowed to pass per second. |
The value is an integer that ranges from 100 to 10240. The default value is 3000. |
Usage Guidelines
Usage Scenario
If there is heavy traffic on the management interface caused by malicious attacks or network exceptions, the CPU is overloaded and services are interrupted. To prevent this problem, run the qos lr pps command to set the rate limit of packets on the management interface.
Precautions
If a small rate limit is used, FTP and Telnet functions may be affected.
If you run the qos lr pps command multiple times on the same interface, only the latest configuration takes effect.qos car inbound
Function
The qos car inbound command applies a QoS CAR profile to an interface in the inbound direction to police traffic entering the interface.
The undo qos car inbound command unbinds a QoS CAR profile from an interface in the inbound direction.
By default, no QoS CAR profile is applied to an interface.
Parameters
| Parameter | Description | Value |
|---|---|---|
| car-name |
Specifies the name of a QoS CAR profile. |
The value must be the name of an existing CAR profile on the device. |
Views
10GE interface view, 40GE interface view, Eth-Trunk interface view, GE interface view, Interface group view
Usage Guidelines
Usage Scenario
After a QoS CAR profile is created, you must apply the QoS CAR profile to an interface to police user service traffic. The qos car inbound command applies a created QoS CAR profile to an interface in the inbound direction.
Prerequisites
A QoS CAR profile has been created using the qos car command.
Implementation Procedure
After a QoS CAR profile is applied to an interface, the system collects statistics on forwarded and discarded packets. You can use the display qos car statistics command to view packet statistics on the interface.
Precautions
- To configure the same QoS CAR on multiple interfaces, perform the configuration on a port group to reduce the workload.
- Configuring the qos car inbound command occupies system resources. If system resources are insufficient, the configuration may fail.
- If a QoS CAR profile and a traffic policy containing the traffic policing action are applied to the same interface, QoS CAR parameters defined in the QoS CAR profile do not take effect. This is because the traffic policy takes precedence over the QoS CAR profile.
- The QoS CAR profile with percent percent-value specified can be only applied to the physical interface.
qos lr
Function
The qos lr command sets the traffic shaping rate to limit the rate of data packets sent by an interface.
The undo qos lr command cancels the traffic shaping rate.
By default, the traffic shaping rate is the maximum bandwidth of an interface.
Format
For S5735I-S-V2, S5735-L-V2, S5735-S-V2, S6730-H-V2, S5732-H-V2:
undo qos lr [ outbound ]
For S6730-H-V2, S5732-H-V2:
qos lr cir cir-value [ kbps | mbps | gbps ] [ cbs cbs-value [ bytes | kbytes | mbytes ] ] [ outbound ]
For S5735I-S-V2, S5735-L-V2, S5735-S-V2:
qos lr cir cir-value [ kbps | mbps | gbps ] [ cbs cbs-value [ bytes | kbytes ] ] [ outbound ]
Parameters
| Parameter | Description | Value |
|---|---|---|
| outbound |
Limits the rate of outgoing packets on an interface. |
- |
| cir cir-value |
Specifies the committed information rate (CIR), which is the average rate of traffic that can pass through. |
For the S5735I-S-V2, S5735-L-V2 and S5735-S-V2:The value is an integer ranging from 1 to 10000000. For the S6730-H-V2 and S5732-H-V2:The value is an integer ranging from 1 to 100000000. |
| kbps |
Indicates that the rate is expressed in kbit/s. |
- |
| mbps |
Indicates that the rate is expressed in Mbit/s. |
- |
| gbps |
Indicates that the rate is expressed in Gbit/s. |
- |
| cbs cbs-value |
Specifies the committed burst size (CBS), which is the committed burst traffic that can pass through. |
For the S5735I-S-V2, S5735-L-V2 and S5735-S-V2:
The value is an integer. The value range differs depending on the CBS unit. The default CBS is expressed in bytes.
For the S6730-H-V2 and S5732-H-V2:
The value is an integer. The value range differs depending on the CBS unit. The default unit is byte. Where:
|
| bytes |
Indicates that the CBS is expressed in bytes. |
- |
| kbytes |
Indicates that the CBS is expressed in kbytes. |
- |
| mbytes |
Indicates that the CBS is expressed in mbytes. NOTE:
This parameter is supported only on the S6730-H-V2 and S5732-H-V2. |
- |
Usage Guidelines
Usage Scenario
When a large amount of data flows are sent from the upstream device to its downstream device, to prevent congestion or packet loss, run the qos lr command to configure traffic shaping on the outbound interface of the device to limit the traffic and burst traffic transmitted over a connection so that packets are sent at an even rate.
Similar to traffic policing, traffic shaping limits the traffic rate. When traffic policing is used, the system directly discards the packets whose rate is larger than the traffic shaping rate. Traffic shaping, however, buffers the packets whose rate is larger than the traffic shaping rate. When there are sufficient tokens in the token bucket, the device forwards buffered packets at an even rate. Traffic shaping increases the delay, whereas traffic policing does not.Precautions
- This command applies only to the outbound direction on an interface.
- When the traffic rate in the outbound direction of an interface is larger than the alarm threshold for the rate limit in the outbound direction of an interface, an alarm is generated.
- If you need to set the same traffic shaping rate on multiple interfaces, you can perform the configuration on a port group to reduce the workload.
- If both traffic shaping and queue shaping (configured by using the qos queue shaping command) are configured on an interface, the CIR of traffic shaping cannot be lower than the sum of CIR values of all the queues on the interface; otherwise, the traffic shaping result may be incorrect. For example, the queue with a lower priority may occupy the bandwidth of the queue with a higher priority.
- Traffic shaping increases the delay because it uses the buffer mechanism.
- If you run the qos lr command multiple times on the same interface, only the latest configuration takes effect.