NAC log showing "Invalid validation request"

[rob.garbee]

I am using Cisco NAC and recently my clients are recieving the error message that the NAC server can not be contacted but the NAC event logs are logging the following message "Invalid validation request" authentication error.  Please help!!!  Cisco TAC ticket number 613983545.

[Jennifer Halim]

Try to double confirm that the shared secret is all the same on all CAS and CAM.

SSH to all CAS and CAM, and check the output of "cat .secret"

If they all match, you would need to increase the logging level, reproduce the issue, and collect the CAM and CAS logs.