Quick Answer

The correct order begins by defining the child policy with per-class actions like policing or queuing, then creating the parent policy that references that child policy with a shaping command, and finally applying the parent policy to the interface, which you verify with the show policy-map interface command. This sequence is mandatory because H-QoS requires the child policy to exist as a modular building block before the parent policy can call it for aggregate traffic shaping; applying the parent without the child first would result in an incomplete configuration. On the ENCOR 350-401 exam, this drag-and-drop task tests your understanding of policy-map hierarchy and the order of operations, with a common trap being the attempt to apply the parent policy directly to the interface without first defining the child. A reliable memory tip is “Child before Parent, then Apply and Verify”—think of it as building a sandwich where the child policy is the filling, the parent is the bread, and the interface is the plate.