Network Admission Control

is configured for NAC, it can force user or machine authentication prior to granting access to the network.

In addition, guest access can be granted to a quarantine area for remediation of any problems that may have caused authentication failure.

This is enforced through an inline custom network device, changes to an existing switch or router, or a restricted DHCP class.

These might include Windows registry settings or the presence of security agents such as anti-virus or personal firewall.

Some, including Hexis' NetBeat NAC,[2] Trustwave, and Enterasys [3][4] offer an agent-less posture checking.