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What to do about "Could not find a table row matching the index you specified when adding the sensor

Votes:

0

Hello,

So recently I started monitoring a few Cisco WLC's using the template provided in the relevant kb post. Everything seemed to be working quite well at first. However, over last weekend the error "Could not find a table row matching the index you specified when adding the sensor" occurred about a 100 times. All sensors eventually returned to a normal state. I've encountered the same problem with the monitoring of the VPN tunnels of a checkpoint firewall using a custom snmp table. When I keep on rescanning the sensor manually, the error eventually goes away,.

The weird thing is that I also use around 150 sensors (snmp custom table) per F5 load balancer to monitor things like virtual servers, pool members etc. without experiencing the same error.

Some more info: License: PRTG Unlimited Sensors: 5100 Hardware: VM 16 GB Ram 8 CPU cores SNMP: V3

Scanning Interval WLC AP: 10 minutes Scanning Interval Firewall: 120s

Thank you.

error-pe247 prtg snmp-custom-table

Created on Jul 15, 2019 7:15:23 AM



Best Answer

Accepted Answer

Votes:

0

Hi there,

I am afraid that there is no real solution to that :(

For PRTG it is an error that should be reported to the user, as PRTG is unable to retrieve the data. The only workaround, which would require some work, is to write a custom script (e.g. in PowerShell) that queries the data and ignores these errors:
https://www.paessler.com/manuals/prtg/exe_script_sensor
https://www.paessler.com/manuals/prtg/exe_script_advanced_sensor

Best regards.

Created on Jul 16, 2019 7:50:16 AM by Dariusz Gorka [Paessler Support]



9 Replies

Votes:

0

Hi there,

At the times, when the sensors throw these errors, are you able to manually walk the monitored OIDs via our SNMP Tester?
https://www.paessler.com/tools/snmptester

Best regards.

Created on Jul 15, 2019 8:49:41 AM by Dariusz Gorka [Paessler Support]



Votes:

0

Hi Dariusz,

I've tried what you suggested and indeed I am not able to walk the monitored OID's when this error occurs. Which is quite a shame, because the monitored things do indeed come back up eventually and then they are reachable by snmp-walk at the same index still.

The only solution I see at the moment is to somehow disable error PE247, but I have no idea if this is possible. Right now I am using a http notification trigger to immediately acknowledge when the sensor goes into an error state. Obviously this is not ideal, because I am not able to discriminate between error PE247 and all other events that cause the error to happen. A more suitable solution would be preferred, if there is any.

Thanks.

Created on Jul 16, 2019 6:59:42 AM



Accepted Answer

Votes:

0

Hi there,

I am afraid that there is no real solution to that :(

For PRTG it is an error that should be reported to the user, as PRTG is unable to retrieve the data. The only workaround, which would require some work, is to write a custom script (e.g. in PowerShell) that queries the data and ignores these errors:
https://www.paessler.com/manuals/prtg/exe_script_sensor
https://www.paessler.com/manuals/prtg/exe_script_advanced_sensor

Best regards.

Created on Jul 16, 2019 7:50:16 AM by Dariusz Gorka [Paessler Support]



Votes:

0

Hello, We have just implemented PRTG and I am in the process of adding one of our many WLC's. I have added the Cisco+WLC+Templates+v0.2 from the previous KB, restarted the core service and added the WLC.

The issue is that all AP's connected to that WLC are showing down with error message "PRTG could not find a table row matching the index that you specified when adding the sensor (196.20.60.40.168.32). The reason might be that the value of the column that you selected has changed. (code: PE247)"

I've left it for 2 hours and the status is still the same.

WLC is 5508 running 8.5.151.0. AP's are AIR-CAP3602I. PRTG is version PRTG Network Monitor 20.4.64.1402 x64

Created on Jan 21, 2021 4:32:05 PM



Votes:

0

Hello Rocky,

The issue is caused by a bug, due to which the sensors are not added properly. This will be fixed in the next stable version 21.x.65. (should come out by the end of January).

Kind regards,
Sasa Ignjatovic, Tech Support Team

Created on Jan 25, 2021 1:21:09 PM by Sasa Ignjatovic [Paessler Support]



Votes:

0

Hello, I'm currently facing the same issue. Has this ever been resolved? What's the solution? Running PRTG Network Monitor 21.3.71.1416 x64 Thanks

Created on Sep 30, 2021 8:50:34 AM



Votes:

0

Hello Q,
we appreciate your contact.

If you refer to the [[https://www.paessler.com/prtg/history/stable|release notes] for version 21.3.71 we mention:

Fixed: SNMP Custom TableAdding SNMP Custom Table sensors with an identification column other than table_index or ifindex properly works again. In previous versions, the sensors showed a down status after creation with error code PE247 in such cases.

I've personally tried out the Cisco WLC device template (Custom Cisco WLC Access Point Status v0.2) with PRTG version 21.3.72.1169+ [Canary] (a test version which includes all fixes from version 21.3.71) and the sensors worked flawlessly. I could only try the template with a simulated device, but regardless it seems like the bug is indeed gone (the bug that specifically affected the Cisco WLC Device template).

Have you deployed the sensors anew after installing version 21.3.71.1416? If not I encourage to do so. And if you continue to encounter issues, please reach out to us with a individual support case and mention this post, so that we can communicate with you directly (as we will require logs for further troubleshooting).

Cheers!
Luciano Lingnau [Paessler]

Created on Sep 30, 2021 12:00:29 PM by Luciano Lingnau [Paessler]

Last change on Sep 30, 2021 12:01:01 PM by Luciano Lingnau [Paessler]



Votes:

0

Good day

I am running PRTG Network Monitor 22.4.81.1532 x64 and this error get shown today, any update on how to solve without creating a script?

Thanks.

Created on Jan 17, 2023 5:40:18 PM



Votes:

0

Hi there,

The issue should be fixed. If not, please reach out to [email protected] so we can take a closer look at it.

Thank you!

Created on Jan 19, 2023 2:52:15 PM by Moritz Heller [Paessler Support]




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