Is there a configuration change I must do (snmpcollector) in order for the "interface utilization" SNMP metrics to show only a max percentage of 100%? Presently the values on this QOS reach up to 240% etc. I have enabled baseline and confirmed the hard data, so why are there 200%+ spikes? The image below shows the lightly colored area being the "spikes" from the raw data.
Why isn't 100% the cap?
There is no way to cap it at 100% it will report whatever the value comes out to be. The calculation to determine that value can vary depending upon the device and mib used. This is the one used for cisco-interface.
This is documented at
UIM SNMP Device Support
So the question becomes why is it reporting 240% utilization.
The first place to look is in the snmpcollector configure > profile for the device > interface > ifspeed.
Note all the values reported may be wrong and it is just that those spikes are what's making apparent there is a problem. If otherwise the values do seem correct and it is just that there is a spike every six hours or so as shown then another possibility is the device has been configured to use a 32bit counter for that interface and the volume of traffic demands a 64bit counter. If there are other devices that are the same model and don't have the problem check the IOS revision and configuration.