Hello All!
I have been trolling both thwack.com and google.com looking for some clues as to why we are seeing a huge discrepancy between the port statistics being reported by SolarWinds and what we are seeing with our MRTG installation (the MRTG has been running for years and the admin, of course, says MRTG is more accurate).
To give you some background, we are running MRTG version 2.14.7 (not the latest 2.16.3 release) on a Dell1850 with Windows2003 Standard Edition (SP2) with Perl v5.8.8 and we are running the 30-day trial version of NPM with all defaults settings on a different Dell1850 with Windows2003 Enterprise Edition (SP2). While we see the same differences with other Cisco gear, the issue that I am posting on is specifically related to our 7606 running 12.2(18) and we are looking at a GigabitEthernet port 2/4.
When we look at the MRTG data (the Daily Graph 5 Minute Average which we have been gathering for years) we are seeing it report about half of the traffic/throughput being reported by SolarWinds. For example, MRTG is reporting on gi2/4 that the average is 38Mb/sec inbound and 59Mb/sec outbound. When we look at SolarWinds, we are getting reports that show the average inbound to be 50Mb/sec and the outbound is showing 185Mb/sec. What is even more surprising is that the peak inbound/outbound being reported by MRTG is 100/120Mb/sec where SolarWinds is showing 453.43/784.39Mb/sec for the same interface.
We are truly perplexed as to how we can have such a range in what is being reported. The only information I could find was a discussion on the differences between Method 1 and Method 2 collection, but nothing specific to why such a major discrepancy would exist between the two products. We are curious if there is something we are totally missing here with respect to NPM or if MRTG is missing the mark and why? Again, your input is GREATLY appreciated and thank you!
Cheers,
Travis