You can use IPM to get some useful historical data on the performance of the links. But sad to say it does not produce utilization reports. If you can gather both IPM and MRTG reports, that will be the best.
It seems like it detect your backup link. It could be either your backup link is activated before or "router as a seed device"Did you put router in the seed device list ?You should only put switches in the list.Reconfigure the seed list... delete all...
