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SNMP suddenly not working anymore




we used builtin "SNMP APC Hardware / SNMP library apc-related" sensor to monitor 4 APC UPS devices for literally years without errors/warnings.

Since 2018/03/07 all of the sensors would show SNMP error 2003 and I can't seem to figure out why.

We use a custom SNMP Community for the requests and everything works just finde outside of PRTG console. I can SNMP request via Powershell and also via Paessler SNMP Tester from my local machine as well as PRTG host.

Strangely when I restart the mgmt interface of the UPS I get some results from PRTG but these last for maybe only 5-10 request (interval = 5 min). Requests "outside" of the sensor work just fine (SNMP Tester or Powershell).

I already tried the following: - reboot of PRTG / reboot of UPS - increased interval time - recreated device in PRTG - recreated SNMP community / tried different communities - recreated the sensors (APC sensor, SNMP library, and custom SNMP sensor)

Are there any known issues with the March 7th 2018 – Version or March 19th 2018 – Version Update?

(Another thing I would like to mention is, that although I set the interval to e.g. 5 minutes, the first requests don't take care about the interval )

Thanks in advance!

apc prtg snmp snmp-error#2003 ups

Created on Mar 28, 2018 10:57:02 AM

3 Replies




Have you tried re-creating the sensors? There are no issues with those updates.

Do you know if the UPS is using SNMPv1 or SNMPv2c?

Created on Mar 30, 2018 6:17:34 AM by  Benjamin Day [Paessler Support] (1,441) 2 1



Hey Benjamin,

as I said, I recreated the sensors. I tried these two: {{https://i.imgur.com/VTzxarg.png|} and SNMPCustomSensor using all kinds of APC OIDs.

Requests work fine for like 5-10 requests but then stop working. We are using SNMPv1.

Created on Apr 3, 2018 6:04:41 AM



Can you check and see if there is a firmware update for your APC unit?

You still run these at 5 minute intervals. Can you try doing 1 hour intervals for the time being?

I'd like to see if it is a quantity issue of the amount of polls, or if it's a timing issue.

Created on Apr 3, 2018 10:53:27 PM by  Benjamin Day [Paessler Support] (1,441) 2 1

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