There is a proxy setup on the network i am using to host an intranet web app. Windows authentication works fine when i access the server using its machine name. However, when i use its IP address, i always get 'you are not authorized' errors. What can i do to resolve this problem, i'm guessing it is the proxy at work when i try to access through the IP.

Are you getting a login prompt? Normally if you are accessing the machine on the LAN (by machine name) then you are already logged on with a domain user account that has access authority. When you try to access it from a "foreign" machine the server issues the NT challenge for authentication. This would normally give you a login screen of some kind depending on how you are trying to access the machine. Login with a valid domain account and you should be ok.

-Peter

thanks for the reply. I wasn't getting a prompt, however I've solved the problem by giving the required IP direct access and not re-directing through a proxy controller