How to configure CPU guard to adjust the number of packets that can be processed by the CPU per second ? Follow

According to the current CPU utilization, CPU guard function sets the CPU utilization high and low watermarks in the percentage of CPU time utilized, and the CPU high and low thresholds in the number of packets being processed per second.

** Please note that the CPU guard will limit the packets transfer to CPU, but it will not limit the packets transmit to the egress port. **

Support Models: ECS4620 series, ECS4510 series, ECS4120 series, ECS4100 series, ECS5520 series, ECS4530 series, ECS2100 series, ECS3510 series

Topology:

Step 1: The switch runs in the default configuration and we try to inject the 1000 packets per second.
The CPU utilization will rise to 55 ~ 58%.

Step 2: Enable the CPU guard function globally.

Console(config)#process cpu guard

At this moment, the CPU remains and doesn't fall.
Since the current CPU utilization does not exceed the value of high-watermark, it doesn't trigger the CPU guard.

Step 3: Modify "low-watermark" and "high-watermark".
For example, we configure "high-watermark" to be lower than the current CPU utilization.

Console(config)#process cpu guard low-watermark 40
Console(config)#process cpu guard high-watermark 50

After the modification, CPU utilization will be falling and the CPU can process 392 packets per second.
It's because the current CPU utilization is higher than the high-watermark, the switch limits the packets flow to the CPU until it falls below the low-watermark.

Step 4: Modify "low-watermark" and "high-watermark".
For example, we configure "low-watermark" to be higher than the current CPU utilization.

Console(config)#process cpu guard low-watermark 50
Console(config)#process cpu guard high-watermark 55

We can see the "Current Threshold" is increasing, and the maximum value is 500 (ECS4510 Series).
If the switch limits the packets flow to the CPU after exceeding the high-watermark, the normal flow will be restored after usage falls beneath the low-watermark.

Step 5: We can also modify the "Maximum Threshold" directly to specify the number of packets being processed per second by the CPU.

Console(config)#process cpu guard max-threshold 100