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Incorrect System Uptime via SNMP



Similar to a question posed by Gerald Schoch [Paessler Support] in August 2014, "Why does the SNMP System Uptime sensor report wrong values?" my SNMP System Uptime sensor shows incorrect uptimes. In particular the system uptime resets to zero every 8days and 2hrs. The device being monitored in this case is an Ethernet module in a programmable logic controller rack:

Schneider Electric Modicon Quantum • 140 CPU 672 60 (processor) • 140 NOE 771 11 (Ethernet module) • 140 NRP 312 00 (fiber converter module)

Does the uptime sensor query the correct OID? How can I fix this wrong system uptime issue?

prtg sensor snmp uptim

Created on Jan 12, 2018 10:50:18 PM

1 Reply



Hi there,

PRTG uses these two OID to request the device's uptime:

  • HOST-RESOURCES-MIB::hrSystemUptime (
  • DISMAN-EVENT-MIB::sysUpTimeInstance (

You can use our free SNMP Tester to start one uptime query before and after the uptime of the device changes in PRTG. You can forward the results here so that we can compare values.

Best regards, Felix

Created on Jan 15, 2018 12:15:05 PM by  Felix Saure [Paessler Support]

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.