Why can the Onguard posture check not be performed during 802.

OnGuard uses HTTPS to send posture information to the ClearPass appliance. For OnGuard to use HTTPS, it must have access to the network. If a customer requires 802.1x authentication on the wired switch, a separate 802.1x authentication must be used prior to the OnGuard posture check. In this example, an 802.1x PEAP-EAP-MSCHAPv2 authentication is completed first. A separate WebAuth service must be setup with posture checks to use the OnGuard agent.

References: MAC Authentication and OnGuard Posture Enforcement using Dell WSeries ClearPass and Dell Networking Switches (August 2013), page 21