Authentication settings in IIS 7.5 and ASP.Net, what is difference?

Question

Hi, I just start to learn web programming using IIS 7.5 in windows 2008 R2, and ASP.Net 4.

I notice that both IIS and ASP.Net can define Authentication rules. In IIS, there is a form authentication setting where I can redirect user to specified page for authentication, like below:

And then, in ASP web.config file, I find similar settings:

<authentication mode="Forms">
  <forms loginUrl="~/Account/Login.aspx" timeout="2880" />
</authentication>

When I finish both settings, I assume any page request will be redirect to the login.aspx page. But it didn't. So I am confused. How do the 2 sets of configs work together? And why page request is not redirected?

Thanks

Update

Finally I get it working and I think I understand it now. My website structure is like below:

It is about modifying Autherization rules. Deny all unauthorized users for root:

    <authorization>
        <deny users="?" />
    </authorization>

CSS files should be allowed for all users, so I have Styles\web.config:

    <authorization>
        <allow users="*" />
    </authorization>

and only allow unauthorized users to access register.aspx, so I have Account\web.config:

  <location path="Register.aspx">
    <system.web>
      <authorization>
        <allow users="*"/>
      </authorization>
    </system.web>
  </location>

  <system.web>
    <authorization>
      <deny users="?"/>
    </authorization>
  </system.web>

Answer 1

There's another component you need to configure: authorization. If you don't, unauthorized users have access to all pages and will not be redirected to the login page. For example:

<authorization>
    <deny users="?" />
</authorization>

This specifies that all unauthenticated users are denied access to pages in your application. The authorization element is part of the system.web configuration section.

Answer 2

When you set something in IIS with authentication ( in your case form authentication). It also change your mapped project webconfig file with the same settings. That's why you see same information in both modules.