The object type that is tracked by this entry. The objects
non-common attributes are in one of the following tables based
on the type:
interface(1) - etsysTrackedObjectsIntfTable
ipRoute(2) - etsysTrackedObjectsRouteTable
portGroup(3) - etsysTrackedObjectsPortGroupTable
portIfSpeed(4) - etsysTrackedObjectsPortIfSpeedTable