What is network access control (NAC)?

Network access control (NAC) is primarily concerned with managing and enforcing policies regarding which devices are allowed to access a given network. It plays a crucial role in maintaining security by assessing the devices trying to connect, ensuring they comply with the organization’s security policies—such as having the necessary updates, antivirus software, or being part of the organization's domain. If a device does not meet these criteria, NAC solutions can restrict its access or quarrantine it to prevent potential threats.

This approach to security enables administrators to maintain a higher level of control over their network environment, ensuring that only authorized and appropriately secure devices can participate in network activity. By doing so, it helps to safeguard against unauthorized access and potential breaches, thus enhancing overall organizational security.

Other options, while relevant to network management and security in their own right, do not accurately describe the primary function of NAC. Managing bandwidth pertains to optimizing network resources, preventing unauthorized physical access focuses on the physical security of facilities, and malware relates to threats rather than access control policies. Therefore, the definition of NAC as a solution enforcing policies on devices aligns perfectly with its intended purpose and implementation within cybersecurity frameworks.