Sorry for the lack of information...
The issue I am seeing is that in order for our reverse proxy to work, the authentication on the IIS site needs to be set to Basic. Out of the box it is set to Integrated Authentication, which is what I want for my internal users.
So, I guess my questions are:
1) If I change the authentication method on the site to basic will anything else break?
2) Has anyone successfully reverse proxied DA v6?