A system and method for discovering security classifications of network areas includes representing actually allowed network flows and flows permitted by a security policy in a format that enables comparison. The actually allowed network flows and the security policy are provided in a networked computing environment including network areas, wherein each network area is a collection of one or more computing and network devices, and enterprise security policy defines security requirements for security classifications. An assignment of security classifications to network areas is determined by comparing the actually allowed network flows with the flows permitted by the security policy.