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Bouncing SNMP results Cisco CPU



I have 2 Cisco Catalyst 4506 switches with a SUP7L monitored in PRTG. Al sensors are working fine except the 'System Health CPU' of both switches. They are up for hours and with no reason the sensor changed to down 'No such instance (SNMP error # 223)' and stays down for minutes to many hours. For both CPU sensors it happens at different time. If I click on the 'Check Now' button it gets a SNMP value and the sensor changes directly to up (most of the times). What can be the problem. Can I increase the snmp retries?

cisco-switch cpu snmp

Created on Jan 13, 2016 9:17:55 AM

1 Reply



Hello Dave,
we appreciate your contact.

It's not a matter or retries, as PRTG is receiving a reply from the device, which is "No such instance". This is a valid SNMP reply which means that the index from the specific OID (each CPU on the device has a distinct index) doesn't exist.

I believe that the most likely explanation would be a bug/issue in the SNMP agent running on your Cisco 4506. Please make sure that it's software/firmware is up-to-date as we've seen similar issues in the past with the SNMP CPU OID's from the Catalyst 4500 series.

Best Regards,

Created on Jan 13, 2016 1:07:18 PM by  Luciano Lingnau [Paessler]

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