NAM top talker stats info showed different from SNMP Manager

[nurmawann]

Hello,

My setup is a Cisco 3845 with NME-NAM-120S module running Version: 4.0(1). I've MetroE interface configured with " analysis-module monitoring " connected to the WAN link.

In few occassions, the SNMP Manager SPECTRUM, detected that this MetroE interface experiencing high BW util, but at the same time when checking on the NAM top talker stats, there was no info about the top talker with such high amount of BW.

This looks like the info captured by SNMP Manager and NAM is different. Could anybody help to advise how I can verify this difference?

TIA

[Joe Clarke]

Exactly what is Spectrum using to determine high bandwidth utilization?  That is, what SNMP objects is it using?  If it's using simple interface bandwidth statistics (i.e. interface octets and ifSpeed), then looking at ONE talker on the NAM would not be sufficient.  You'd need to look at all talkers plus any layer 2 only traffic (which wouldn't appear in top talkers).  In that case, you would also want to look at the CLI counters for this interface to check both the NAM and Spectrum.

[nurmawann]

Thank you Joe for your prompt reply and tips.

The SPECTRUM is using simple interface bandwidth. The sum of all talkers plus any layer 2 traffic was still way below the reported high BW util. Apparently it was reported that after removing rate-limit command configured on the sub-interface FastEthernet (the interface that is being monitored by NAM & SPECTRUM), there was changes on the top talker stats info, although the total talkers stats still wasnt as high as reported high BW.

As per your suggestion, I'm going to monitor the CLI counters of the interface.

Thanks again.