I'm running my site in DNN 5.1. We've configured router to map a public ip to local ip & port. We've an AD with user details. If i enable windows authentication, along with AD, new users from intranet are not able to login(indefinite loop). So i need to enable only AD along with forms, so that any new user from intranet is logged in.  However users from internet are not authenticated it seems. The browser throws dialog box to enter credentials. If they cancel or enter wrong password it does not allow acces. If they enter correct password they are redirected to home page but instead of their name "Register" is displayed. Also in Forums they cannot reply or create new thread. So it seems they are not logged in. I'm stuck here. Please let me know -

1. Whats the best configuration for intranet and public ip access - AD/Windows?Whats the difference in configuration?

2. Why does it display "Register" instead of user name when people access from internet?

Thanks Mike. But we need to authenticate external(internet) users based on their AD/Windows credentials, which they enter in the dialog box.

With the setup as I described above external users will still be able to login they'll just have to do it manually. If you go to the site I mentioned above and click on login, if you were a domain user you could enter your username/password and you'd be logged in.

However, if you're set on having your external users have the IIS popup, I'd check your IIS logs for any errors when they attempt to login. What happens if they try to manually login using the DNN process? I had a student all ticked off at me the other day because every time he tried to login it complained about his password. After troubleshooting with him on the phone I found out that he had ZoneAlarm running on his computer and it was blocking his credentials when he entered them. As soon as we disabled it he was able to login just fine so it's possible that something on your external users computers are blocking their credentials.