Process Snmp (PDU Dispatcher) causes High CPU value?

[GulbadinNaib]

Hello,

I have a Catalyst Switch 6000. Inoticed that after the execution of the job inventory in LMS, and after the snmp queries reached the equipement, the cpu value reached 98-99 % due to the process : PDU DISPATCHER (what’s it ?)

I have also a script running in the switch to observe the differents logs. For exemple, when high cpu is obtained, the message bellow appear :

« %SNMP-3-INPUT_QFULL_ERR: Packet dropped due to input

« %SNMP-3-INPUT_QFULL_ERR: Packet dropped due to input

« %SNMP-3-INPUT_QFULL_ERR: Packet dropped due to input

....

Could you give me any idea or help ?

Thanks in advance.

[balaji.bandi]

what is the version of IOS Code running here ? check the BUG and work around as below

Workaround: restarting the snmp process (unconfigure/configure snmp-server) may resolve the problem temporarily.

[Georg Pauwen]

Hello,

since it is a Catalyst 6000, the bug below might apply:

%SNMP-3-INPUT_QFULL_ERR when polling the CISCO-SWITCH-ENGINE-MIB
CSCul86573
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Description
Symptom:
A Cisco 6500 generates the error message when polling the CISCO-SWITCH-ENGINE-MIB:
"%SNMP-3-INPUT_QFULL_ERR: Packet dropped due to input queue full".

Conditions:
A supervisor 2t engine running 15.1(1)SY1 on cisco 6500 generates the error message " SNMP-3-INPUT_QFULL_ERR Packet dropped due to input queue full".
This issue has been found when the switch is added to Ciscoworks LMS and an inventory collection job runs. The job queries CISCO-SWITCH-ENGINE-MIB and the switch stops responding to the snmp and we can see SNMP-3-INPUT_QFULL_ERR Packet dropped due to input queue full in the logs of device.

Workaround:
Do a warm restart of SNMP ENGINE to get device respond to snmp request.
OR
Create a snmp-server view blocking this portion of the mib tree or the CISCO-SWITCH-ENGINE-MIB.
ie:
snmp-server view cutdown iso included
snmp-server view cutdown 1.3.6.1.4.1.9.9.97 excluded

Apply the view to your community:

no snmp-server community < your string here> RO
snmp-server community < your string here> view cutdown RO