System health validators (SHVs) are server software counterparts to system health agents (SHAs). Each SHA on the client has a corresponding SHV in Network Policy Server (NPS). SHVs allow NPS to verify the statement of health (SoH) that is made by its corresponding SHA on the client computer.
SHVs contain the details of the required configuration settings on client computers. For example, the Windows Security Health Validator (WSHV) is the counterpart to the Windows Security Health Agent (WSHA) on client computers. WSHV allows you to create a policy for the way in which settings on Network Access Protection (NAP)-capable client computers must be configured. If the settings on the client computer as reported in the SoH do not match the settings in the SHV on the server running NPS, the client computer is not compliant with health policy.
To extend this example, if you configure the WSHV to use the setting A firewall is enabled for all network connections, the firewall software that is running on the client computer must be Windows Firewall software or other firewall software that is compatible with Windows Security Center. If the client computer is not running Windows Firewall or other firewall software that is compatible with Windows Security Center, the NAP agent on the client computer sends a SoH to NPS that reports this fact. NPS compares the SoH to the configuration of the WSHV in NPS; NPS then determines that the client computer is not compliant with health policy.