Network access control (NAC), also called network admission control, is a method of bolstering the security of a proprietary network by restricting the availability of network resources to endpoint devices that comply with a defined security policy.
NAC is ideal for corporations and agencies where the user environment can be rigidly controlled. However, some administrators have expressed doubt about the practicality of NAC deployment in networks with large numbers of diverse users and devices, the nature of which constantly change. An example is a network for a large university with multiple departments, numerous access points and thousands of users with various backgrounds and objectives.
Network Access Control (NAC) is a computer networking solution that uses a set of protocols to define and implement a policy that describes how to secure access to network nodes by devices when they initially attempt to access the network.
NAC might integrate the automatic remediation process (fixing non-compliant nodes before allowing access) into the network systems, allowing the network infrastructure such as routers, switches and firewalls to work together with back office servers and end user computing equipment to ensure the information system is operating securely before interoperability is allowed. A basic form of NAC is the 802.1X standard.