Autodiscovery duplicate sensor

Hello psechi,
thank you for your inquiry.

If you're seeing duplicate sensors while using standard templates, the most likely explanation is that you're mixing up sensors that have been created manually and by the auto-discovery. If that is the case, I encourage you to delete all existing sensors on the relevant device and re-run the auto-discovery to make sure that all existing sensors were created by the auto-discovery.

Further auto-discoveries following this "first" discovery should not create any more duplicates. Should this continue to happen after doing the above, we'll need to know what precise sensor type is affected (leading to duplicates) to investigate this further.

Best Regards,
Luciano Lingnau [Paessler Support]

Hello,

thanks for your reply.

All existing sensors have been created by the Automatic device identification (standard), but when i run auto-discovery to update and add new sensors, then i see duplicates.

You can find below an example for understanding:

I look forward for your reply.

Thanks Pietro S.

Hello Pietro,
thank you for your reply.

Please check the settings tab of two sensors for the same interface. For example Gi0/0. In the settings tab of both sensors there will be a Interface Number value in the settings.

Please let me know the content of this field for both interfaces (original and duplicate). It should be something like:

Best Regards,
Luciano Lingnau [Paessler Support]

Hi,

same Interface number for both of them:

Thanks, Pietro

Hello Pietro,
thank you for your reply.

Could it be that you're mixing up Custom and Standard device templates? This could also explain what is happening.

The auto-discovery won't be able to avoid duplicates if you're mixing up custom and standard templates. When you want to re-discover new sensors on a schedule, you should always use the very same set of templates.

Please delete all sensors and perform a new auto-discovery. Then, re-run the discovery and confirm that no duplicates were created.

Best Regards,
Luciano Lingnau [Paessler Support]

I finally found this article after trying to track down why we keep getting duplicates of the same interface (SNMP index) over and over.

In our scenario, we added the device using the "Default auto-discovery (recommended)" option, and then later we built a custom template to only add a few items like ping, uptime, and interfaces (excluding the ROM). This caused duplicates which we do not want since they already exist.

Is there any way to not have these interfaces added a second time as it shouldn't? If we delete the originally created sensor we will lose historical data which is not what we want.

Please advise.

Hello Crawc,

On the auto-discovery group settings, what option do you have for the Handling of Already Known Devices option?

If you select Skip auto-discovery for devices/IP addresses already known within PRTG, PRTG does not create a duplicate device for a DNS name or IP address that is already represented in the device tree.

Note: If you select Perform auto-discovery for devices/IP addresses already known within PRTG, PRTG adds all found devices to this group and only scans new devices for sensors. This might result in PRTG including devices that already exist in other groups.

If the problem is sensors are duplicated instead, please feel free to contact us directly at [email protected] so check with more details.

Thanks

Sorry, I should specified more. We have having this problem only with SNMP Traffic Interfaces. We are not using auto-discovery groups.

Example: The device was added, one at a time as they were installed, etc., years ago. Which the "Default auto-discovery (recommended)" added sensors for all interfaces. Now that I have applied our slimmed-down device template (with includes and excludes) we apply it to the existing device and on autodiscovery the SNMP Traffic Interfaces get duplicated.

If we delete the existing SNMP Traffic Interfaces sensors then we lose all historical data. Which is not desired.

Thanks Crawc,

This is not expected, we may need to check with more details. Please contact us at [email protected] to investigate further.

Hello Michael,

We recommend to open a ticket to review details and investigate further. Please contact us at [email protected]