Last week Microsoft released Forefront UAG SP1 Update 1 (http://www.microsoft.com/download/en/details.aspx?id=27604). After installing the update our DirectAccess clients lost corporate connectivity.
A quick look on our UAG server learned that the DirectAccess Monitor reported the DNS64 as Not Healthy.
Looking through the UAG services I discovered that the Microsoft Forefront UAG DNS64 Service was not running and had the start type Manual. Starting the service restored the corporate connectivity for the clients. I’ve changed the startup type to automatic to make sure DirectAccess continues to work after a reboot of the server.