Cisco Trust Agent collects security posture information from the NAC-compliant applications running on the network client and reports them to the Cisco Secure Access Control Server (ACS). These are some NAC-compliant applications:

- Antivirus applications

- Personal firewalls

- Host-based intrusion protection applications, such as Cisco Security Agent (CSA)

Cisco NAC is a strategic element of the Self-Defending Network. Working together with other Self-Defending Network components such as Cisco Security Agent and the Cisco Security Monitoring, Analysis, and Response System (Cisco Security MARS), Cisco NAC helps organizations achieve more accurate threat identification and prevention while increasing patch management efficiency.