28. Network Access Control (NAC) Deeper Dive

NAC is used to stop unwanted devices from connecting to a network.

It checks devices before allowing access. Depending on the setup, NAC can require the user to accept an acceptable use policy, provide credentials, or meet specific security requirements.

Some NAC systems enforce device compliance by validating the device (like checking its hardware identity or using installed agent software) and confirming security posture (for example, updated OS and antivirus).

NAC can also place devices into different network segments. Approved corporate devices may get internal access, while personal or untrusted devices may be limited to a guest network with internet-only access.

Main Idea
NAC controls who and what can join a network by verifying identity and security compliance, then granting the right level of access.