When Manual override needs to be setup?
Manual override is the functionality which interface speed can be changed manually instead of taking the value from ifspeed/ifHighSpeed.
You may setup manual override when actual speed of the interface is not align with ifspeed/ifHighSpeed on mib.
Also, if you see following alarm, interface_traffic is failing to get ifspeed/ifHighSpeed. In this case, you need to setup manual override.
The max interface speed (ifSpeed) of '$ifName' on '$agent' could not be determined!