Product and Software: This article applies to the Microsoft IAS server and all ArubaOS versions.
The IAS server displays error messages when a user is not authenticated. These error messages are identified using Event ID, Reason-code, and Reason.
This article describes two errors with the Event ID 2 and Reason-code 66.
Reason = "The supplied message is incomplete. The signature was not verified" The issue may occur if IAS is installed on the Windows Server 2003-based computer and the Trusted Root CA certificate is not installed on the client computer.
Reason = "The user attempted to use an unauthorized authentication method." Verify that the IAS server is authorized to access the Active Directory to verify the Remote Access permissions for users. Use the "Action", "Register Server in Active Directory". After this is enabled, make sure that the specified authentication type is checked in the Remote Access Policies (the name of the policy is listed in the Policy-Name section of the event description).