Domain user authentication in ASP.NET

I would like my asp .net web application to only allow users belonging to DomainName\Domain Users to access the site. Right now I have "Anonymous access" disabled and "Windows Integrated Security" enabled on IIS. I also have the following code in my web config:

<authentication mode="Windows" />
<authorization>
    <allow roles="DomainName\Domain Users" />
    <deny users="*" />
</authorization>

When I attempt to access the website it prompts me for the username开发者_Python百科 and password to connect to webserver.example.com. I am a member of the domain users group but it does not allow me access. What am I doing wrong either in the syntax or in my IIS settings?

Is Anonymous Authentication Disabled in IIS ? Only Integrated Windows Auth should be enabled on the web application.

EDIT from comments: I see you have Anonymous disabled. Try adding <identity impersonate="true" /> within <system.web> and see if your behavior changes.