I'm trying to use my FFTMG to load balance my CAS array by pointing the CAS array URL to my FFTMG. The result is that it is prompting my clients for their credentials and it takes about a minute to connect successfully. The workstations are domain joined and should not prompt for authentication. It shouldn't prompt them for their credentials and it shouldn't take but 5 seconds or less to connect.
Enabling forms-based authentication for external and internal Outlook Web App 2010 (OWA 2010) users where Exchange 2010 is published using Forefront TMG 2010.
http://www.msexchange.org/articles_tutorials/exchange-server-2010/management-administration/enabling-forms-based-authentication-external-internal-owa-2010-users-exchange-2010-published-using-forefront-tmg-2010-part5.html