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Problems with SNMP traffic sensor



I have a problem with SNMP traffic sensors on some server interfaces. I create the sensors manualy. When I get the list of interfaces, they are all there and I select the ones I am interested in. But as soon as PRTG starts polling them, it fails, giving "No Such Name (SNMP error #2)".

I suspect this happens when the ifAlias and/or ifDescription has a colon character (:) in it. For example, I am looking at an interface that has ifDescription "Device vmnic0 at 03:00.0 bnx2", and ifAlias "03:00.0".

How can I work around this?

Best regards Kevin DORRELL Luxembourg

error ifmib prtg

Created on Nov 15, 2012 1:58:07 PM

4 Replies



Could it be that the traffic in is showing / working, but not the traffic out?

What precise version of SNMP are you using (v1, v2c, v3)? Were the sensors added using 32-bit or 64-bit counters?

If 64-bit, please check if using SNMP v1 (32-bit) works. It is highly unlikely the issue has to do with the name entry.

Created on Nov 16, 2012 12:37:01 PM by  Patrick Hutter [Paessler Support] (7,225) 3 3



Thank you, that was a good catch. I interrogated the server with SNMP version 1 and it worked correctly. The strange thing it is that I have about 20 identical servers, and only two of them are showing this behaviour. I shall ask the server guys to check their SNMP is configured for version 2c.

Best reagrds Kevin DORRELL Luxembourg

Created on Nov 16, 2012 1:51:54 PM



Further to this problem, I have a suggestion. In the current version, you can bind a sensor to one of two keys:

ifAlias ( from ifMib, which is recommended ifDescr ( from the older interface MIB

For some server implementations it would be really useful to be able to bind the sensor to ifName (

Best regards Kevin Dorrell Luxembourg

Created on Jan 22, 2013 8:23:03 AM



We'll put this on the wishlist!

Created on Jan 24, 2013 3:42:52 PM by  Torsten Lindner [Paessler Support]

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