NAC (Network Access Control)

NAC (Network Access Control) applies policy when devices or users connect to wired or wireless networks. It may use identity, device posture, certificates, location or role to assign access, quarantine or remediation, depending on integrations. NAC does not automatically know that every device is trustworthy, and a failed dependency can block legitimate work or grant fallback access. Design should define authoritative identities, device ownership, unmanaged and guest paths, enforcement points, exceptions and behaviour when authentication services fail. Discovery mode helps reveal unknown equipment before blocking. Certificates and posture agents require lifecycle management. Tests should cover authorised, denied, expired, non-compliant and emergency cases on real ports and wireless networks. A successful connection does not prove least privilege if the assigned VLAN or policy allows excessive communication.