Hi Support team, we have a strange problem here: We are monitoring a customers Stonegate Firewall with PRTG for several weeks now without any problem. Since last week all SNMP sensors on that machine don’t work anymore, only PING works fine. In SMC we can see that the system is up and running. We get two different error messages:

1) SNMPERR_AUTHENTICATION_FAILURE (SNMP-Fehler # -35)

2) No response (check: firewalls, routing, snmp settings of device, IPs, SNMP version, community, passwords etc) (SNMP-Fehler # -2003)

All sensors switch between these error messages without cause, most of the time it’s the first one.

So we used SNMP Tester (both versions) on the probe itself to check the credentials. They are correct and SNMP Tester works perfectly.

Unfortunately we cannot reboot the firewall. Do you have any idea how to get the sensors back to work?

Thanks in advance! Regards, Marc

Article Comments

Did you try running the SNMP Tester on the same system, the PRTG probe is running on? Did you try restarting the probe service?


Apr, 2013 - Permalink

Hi Johannes, yes, we did run the tester on the same device. And your Tip was terrific, restarting the probe service actually solved our problem. All sensors green now :-) Thank you very much for your help! Regards, Marc


Apr, 2013 - Permalink