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A number of Cisco Devices configured with the same SNMP3 Credentials

Within PRTG Credentials inherited from Root...

Cisco Nexus 5672UP working fine with SNMP until yesterday when we had to swap out due to failure.

New Cisco Nexus 5672UP installed with the same configuration as before

Now in PRTG we are seeing the error "SNMPERR_AUTHENTICATION_FAILURE(SNMP error # -35)" for this device.

All other devices working fine

snmptrafficsensor snmpuptimesensor snmpv3

Created on Sep 7, 2018 10:04:25 AM

5 Replies



Did you use the SNMP Tool that you can download on the PRTG website and test this?

Sounds like there is some mismatch in your configuration. Probably the password wasn't transferred or needs to be reset or something like that.

You find it here - you might wanna use the PRTG Probe-Device for testing, to be on the same IP address assuming there might be restrictions in regards to IPs as well.


PS: You might wanna do a DEBUG SNMP or similar on the Cisco device as well - there is a good chance you see what is the issue. I still would just overwrite the SNMP password and double check that the config has the correct values. Pretty common that issue is that either the running config wasn't saved on the flash (copy run start) or no good backup was in place - where I recommend things like CATTools or similar and constantly backup the running-config - what is the current config... the startup-config might be outdated..


Florian Rossmark


Created on Sep 7, 2018 1:49:26 PM



Thanks for the reply...

You mentioned in your response above "I still would just overwrite the SNMP password and double check that the config has the correct values", did exactly this and fixed the issue.

Something to bear in mind when replacing kit. Even when using the saved configuration from the old device it will not necessary work on the new device.

Created on Sep 10, 2018 9:53:56 AM



Hello taylor5,

So overwriting the password manually fixed the issue? Which language do you have configured in PRTG? There is currently an issue with certain languages that leads to passwords turning into rubbish when they're encrypted by PRTG due to missing unicode support and the error pops then up after a restart of PRTG.

Kind regards,


Created on Sep 10, 2018 11:22:30 AM by  Erhard Mikulik [Paessler Support]



Language - English United Kingdom

It was the password configuration for snmp v3 on the Nexus5K I re-applied that resolved the issue, even though it was the same details.



Created on Sep 10, 2018 11:27:30 AM



Ok, shouldn't happen with the English language setting, maybe something else, pleas keep an eye on if the issue re-occurs after a PRTG update, otherwise it should be fine then.

Kind regards,


Created on Sep 10, 2018 6:28:03 PM by  Erhard Mikulik [Paessler Support]

Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.