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

Article Comments

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.


Nov, 2012 - Permalink

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


Nov, 2012 - Permalink

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

ifAlias (1.3.6.1.2.1.31.1.1.1.18) from ifMib, which is recommended ifDescr (1.3.6.1.2.1.2.2.1.2) from the older interface MIB

For some server implementations it would be really useful to be able to bind the sensor to ifName (1.3.6.1.2.1.31.1.1.1.1)

Best regards Kevin Dorrell Luxembourg


Jan, 2013 - Permalink

We'll put this on the wishlist!


Jan, 2013 - Permalink