How can I fix the No Such Instance (SNMP Errors #223) error on a PRTG System Health Temperature sensor for a Cisco device, which resumes polling data when paused and resumed or recreated?

The error message appears when a metric that was available during sensor creation is no longer returned. This means, the query is sent out properly, but the device did not reply.

You need to dig a bit deeper here to see if the device replied or what the target Cisco device returns in case of an error.

You can do this in the following way:

  1. Install WireShark.
  2. Create a capture filter (not display filter)
  3. Forward the pcap file after you tried to add the sensor at least twice. The filter looks like this: host 172.30.254.73 and udp port 161 Replace the IP address by the IP of the Cisco device.


Disclaimer:
The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.