Spontaneous high Routing Engine CPU utilization

While processing updates, the Routing Engine (RE) CPU may show a utilization spike for a couple of seconds. This is normal behavior and can be safely ignored.

Sometimes the Routing Engine (RE) CPU may spike for a couple of seconds. This spontaneous RE CPU spike is generally observed during processing updates. This may include RPD updates like route updates (which cannot be seen in log messages), kernel tasks, SNMP/MIB processing, etc. While processing such updates, additional CPU resources would be utilized which can trigger a momentary CPU spike for few seconds before it returns to a normal state.

While processing the updates related to RPD, kernel, SNMP, etc., additional CPU resources may be called upon, which can trigger a momentary CPU spike. If the CPU utilization continues to remain high for long time, then this a possible concern which needs to be analyzed further. If the RE CPU continues to remains high, check which process is being excessively utilized by executing the following command:

This is expected behavior and this sort of sudden spike for few seconds will not cause any problem during normal operations. It can be ignored.

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James Palmer

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