Hi , just checking out this thread late. I tried using 'DNN_ActiveDirectoryAuthentication' Extension for AD logins on our intranet. It worked, but I found that it didn't work for users across multiple portals. We're going to have several separate sites on our intranet DNN, where we need AD users to be able to log in to all the sites. When I tried this using 'DNN_ActiveDirectoryAuthentication' , it caused things to break.
I ended up going with Glanton Ad-Pro, which has a good solution where a single user is logged in across multiple portals (with a separate username in each portal, but pointing to a single AD user) . It seems to work pretty well.
Just thought I would chime in, since I'm new here.