Weird IIS authentication problem.

[MrGrim]

Consider the following setup. A network that is connected to the internet via a Firewall. Somewhere on the network there is a DMZ with a webserver. Keep in mind that the webserver is not visible to the rest of the PCs on the network, if I connect a PC on the network I can't access the webserver in any way but through it's internet IP.

The webserver is hosting a website using IIS5 and Frontpage Server Extensions. The main site is open to everybody, no login is required, but parts are protected and require the user to login in order to access them. So if you are on a PC on the LAN and you hit that site you browse freely, but when you hit a protected part of the site you get a window's login pop-up and you have to enter a user name, password and domain.

This is OK, this is how it's supposed to work. The problem is when we use a PC that is not part of the network (if YOU tried to access it for example) you never get a chance to login, the connection is refused as soon as you hit the portected part of the site. To be exact this is the error message that you get (which is the same message that you get when you click cancel on the windos's login pop-up)

HTTP Error 401
401.3 Unauthorized: Unauthorized due to ACL on resource

This error indicates that the credentials passed by the client do not have access to the particular resource on the server. This resource could be either the page or file listed in the address line of the client, or it could be another file on the server that is needed to process the file listed on the address line of the client.

Please make a note of the entire address you were trying to access and then contact the Web server's administrator to verify that you have permission to access the requested resource.

 

[neopipil]

Look at some of these documents. From what I have seen it the past, it may be a permissions problem.

Look here