Network Access Control requirements are typically implemented in practice as a series of heterogeneous security-mechanism-centric policies that span system services and application domains. For example, a Network Access Control (NAC) policy might be configured in terms of firewall, proxy, intrusion prevention and user-access policies. While defined separately, these policies may interoperate in the sense that the access requirements of one may conflict and/or be redundant with respect to the access requirements of another policy. Thus, managing a large number of distinct policies becomes a major challenge in terms of deploying and maintaining a meaningful and consistent configuration. It is argued that the Semantic Web--an architecture that supports the formal representation, reasoning and sharing of heterogeneous domain knowledge--provides a natural solution to this challenge. A risk-based approach to configuring interoperating policies is described. Each NAC mechanism has an ontology...
William M. Fitzgerald, Simon N. Foley, Mích