Paul, I'm not sure if your response is correct. NetApp Connect does not depend upon ONTAP for AD authentication.
To the original poster (sorry, I don't know your name), my guess is you've setup the AD parameters, but you didn't also enable AD authentication. Please login to the dashboard as the built-in admin user, go to the "Policy & Configuration" tab, and ensure that the "User Database" setting under "Authenticator Configuration" is set to "Microsoft Active Directory". Even if you've setup all the Active Directory parameters, you also need to enable AD. If it's set to "Internal Database", please set it to MS AD, then click the stage changes button beneath that section of the form, and then execute the changes to actually enable it. The screenshot below shows what I'm suggesting.