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SNMP Sensor not saved in Device Template



I have a device with 2 sensors. (Telnet check and Custom SNMP) I created a template of this device and then removed the 2 working sensors.. (So the device has no sensors now) Then I ran the autodiscovery (with Template) on the device. But i seem to always run in to the same scenario... The Telnet sensor is added and Green again, but the Custom SNMP sensor never shows up.. When i add the SNMP sensor manually, or clone it from another device it works fine again...

So, this leaves me to conclude that the "Create device Template" function cannot be trusted and is broken...?

I have arround 1000 IP phones that eventually need to be added, and i want them to be autodiscovered using the phone template i created.. But if sensors (That worked fine before) are now just being ignored this entire function is completely useless.. Then its even faster to Clone a working device a 1000 times, instead of having to check each device after autodiscovery if the sensor has been added "Yes" or "No".....

Can this be fixed??

autodiscovery device-template snmp

Created on Jul 11, 2018 2:12:14 PM

3 Replies



Hello Randy,

Thank yo very much for your contact.

Please contact us directly via email to [email protected]. Please re-run the auto-discovery procedure (deleting the sensors, then adding them via the template) and provide us with:

  • full-screen screenshots (neither cropped nor resized) from the steps you do
  • the Auto Discovery Debug Log (n).log from the PRTG Core Server which can be found in the following directory: <your-prtg-core-server>\C:\ProgramData\Paessler\PRTG Network Monitor\Logs (System)
  • the selected .odt template file from: <your-prtg-core-server>\C:\Program Files (x86)\PRTG Network Monitor\devicetemplates

Thank you very much in advance.

Created on Jul 12, 2018 7:39:24 AM by  Sebastian Kniege [Paessler Support]

Last change on Jul 16, 2018 8:18:15 AM by  Sebastian Kniege [Paessler Support]



Hi Sebastian,

I did what you requested but not long after i found a workaround to the problem.. I noticed the auto-discovery logs showed the following:

11-7-2018 16:00:46: Template Check; Device ID: 2475; Check ID: snmp; ERROR: 106

This gave me an idea because the telnet sensor in the device-template uses "PING" to identify a connection before adding the sensor. I noticed that SNMP requires "SNMP" to identify the connection... (Somehow this failed, and the sensor is not added) I dont know what auto-discovery exactly checks when testing the SNMP before adding the sensor, but all our SNMP daemons are custom so most of the "Default" SNMP values do not exist in it...

So I went into the template file and changed the following:

<check id="snmp1." meta="snmp" requires="SNMP">


<check id="snmp1." meta="snmp" requires="PING">

I then deleted the 2 sensors from the device again and ran the Auto discovery with Template. Within seconds the 2 sensors re-appeared again..

This leads me to conclude that the SMNP check that Auto-discovery does is not functioning correctly.. I don’t know what A-Disc. Exactly does but I think it isn’t polling the snmp oid correctly, or the timeout is WAAAY too short.. (Even though my devices respond within milliseconds)

At least now your development knows where to start the search to fix this issue.. (Should be relatively easy) But for now I can bulk change all my template to require "PING" instead of "SNMP" for the discovery process.

I posted this issue here on the forum for other people running in to this problem.. It has also been communicated to the support team via e-mail.


Created on Jul 13, 2018 11:29:36 AM

Last change on Jul 16, 2018 6:56:54 AM by  Luciano Lingnau [Paessler]



Dear Randy,

Thank you very much for both, your contact at [email protected] as well as sharing your findings here in our knowledge base.
For the sake of completeness and also for providing the information with others, please allow me to sum up the findings of Luciano and me and publish it here as well.

The following check id from the device template's .oid file is not working properly: <check id="snmp1." meta="snmp" requires="SNMP"> The reason for it is that PRTG's internal SNMP check requires the following OID's which must exist/respond: oid := ''; oid := ''; oid := ''; The custom SNMP implementation is missing any of these and while your above written workaround is correct, the original behavior is expected and by design.

If we can be of further assistance, please let us know.

Best regards,

Created on Jul 16, 2018 8:12:40 AM by  Sebastian Kniege [Paessler Support]

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