ASP.NET implements additional authentication schemes using authentication providers, which are separate from and apply only after the IIS authentication schemes. ASP.NET supports the following authentication providers:
Windows (default)
Forms
Passport
None
To enable an authentication provider for an ASP.NET application, use the authentication element in either machine.config or Web.config as follows:
Code:
<system.web>
<!-- mode=[Windows|Forms|Passport|None] -->
<authentication mode="Windows" />
</system.web>