LibreNMS & QNAP = [SNMP] DoS detected


Issue :

This Is most likely just because of the volume of snmp queries we do. If you don’t expose snmp to the outside world then disable the checks in your qnap

A similar issue has affected me since the February 17th update. All 4 of my qnaps stopped responding to snmp queries but the qnap log has no mention of DoS. If I restart the service on the qnap it works for a few minutes then stops (i’m guessing until librenms polls it). I am working with qnap to confirm on that end if it is a security measure. I have removed and re-added 2 of the qnaps from librenms and the problem has gone away for for them. Before I reset the other 2 is there any info I can get for you that will help you to address what happened to cause this?
[Edit] I have turned off the Qnap DDoS detection and it still occurs. I also noticed that it happened right after an update that changed some of the qnap polling code. Barring any feedback by the devs by tomorrow I will just delete and re-add the devices. Since it works on fresh devices I assume that it is just a glitch that has occurred because of the code change and update.

I can’t remember the exact info but do SELECT * FROM sensors WHERE device_id=X; in mysql - replace X with the device_id. Look for an OID which ends in a . (they should end up in numbers). Delete that one rogue value.

Thanks. It wasn’t one rogue one ending in “.” but 4 extra long ones. See snippet below:

All fixed now.