Network Access Control is an approach to IT security that attempts to unify endpoint security technology (antivirus, host intrusion prevention, and vulnerability assessment), user or system authentication and network security enforcement.
NAC is transforming from simply basic access or admission control into a more sophisticated set of controls for endpoint visibility, access, and security. Unlike its overly complex and complicated ancestor, the newest generation of NAC solutions utilize advanced contextual data gathered from a number of different sources in order to enforce granular, dynamic network access policies.
In essence, these solutions leverage the network as a sensor in order to make proactive access control decisions. For instance: applying different access policy depending on the device being used or the compliance state of the device; enforcing access to prevent unauthorized lateral movement across a network or throughout the extended network – regardless of how authorized users or devices connect.
As such network access control (NAC) has evolved into a fundamental network security defense solution.