Which of the following best describes the function of NAC?

The function of Network Access Control (NAC) is primarily to enforce security policies on devices attempting to access the network. NAC solutions are designed to ensure that only compliant devices are permitted to connect, thereby helping to maintain the overall security posture of the network.

When a device requests access to the network, NAC evaluates it against predefined security policies, which may include checks for up-to-date antivirus software, operating system patches, and configuration settings. If a device does not meet the necessary criteria, NAC can restrict its access or direct it to remedial resources to rectify the deficiencies.

This proactive approach helps prevent threats from unsecure or compromised devices and ensures that all devices on the network adhere to the organization's security standards, thereby reducing the risk of security breaches or malware propagation.

Other choices do not accurately describe the primary role of NAC. For instance, allowing unrestricted internet access does not align with the purpose of NAC, which is to regulate and enforce those very access controls. Monitoring network traffic for breaches and managing software permissions are functions associated with other security solutions and practices rather than the core function of NAC.