The validation of policy is necessary to ensure that it will lead to a feasible implementation for the environment. This requires checking that the policy is consistent with the functional or resource constraints within the target environment. For example, do the policies assume functionality or specific operations, which do not exist in the target routers, or bandwidth in excess of the capacity of the data links? The objective is to support static checking, where possible, prior to deployment in order to detect invalid policies at design time. However there are some policies related to resource allocation that depend on the current state of the system, and require policy constraints that must be checked at execution time. In this paper, we will discuss how CIM can be used within the Ponder Policy Framework to validate network policies that apply to a Differentiated Services (DiffServ) domain against the capabilities of the individual network elements that comprise the DiffServ domain.