1. A system, comprising: a remote access device that requests access to a central resource; and a computer executing a hierarchical policy manager that determines a policy for allowing the device to access the resource by evaluating access policies at a plurality of precedence levels of a policy hierarchy; wherein the hierarchical policy manager allows the device to access the resource based on a policy set at the highest precedence level of the policy hierarchy at which access control is specified; and wherein the hierarchical policy manager allows the device to access the resource based on a policy set at the lowest precedence level of the policy hierarchy at which access control is specified and at which an override flag is set.