NAC is a solution to define and implement a policy by control access to a network with policies, including pre-adminssion endpoint security policy checks and post-admission controls over where users and devices can go on a network and what they can do.

• InfoExpress : Dynamic NAC - Network Access Control without Network Changes. The number 1 rated NAC solution that provides the easiest installation and deployment.
• Symantec Network Access Control : Network security software solutions providing comprehensive endpoint enforcement