If you have already set up Forms Based Authentication(FBA) in SharePoint 2010 public beta, you would have noticed not much of a change from SharePoint 2007. As you are aware, SharePoint 2010 includes new authentication model called Claims Based authentication. You can read more about this here. Since the SharePoint 2010 RTM, FBA now requires claims mode set up for the web application. Your membership provider and role provider now acts as the Identity Provider.
So, if you go to your web application settings, and choose to edit the Authentication Providers, you will notice the following:
Notice that there is a help on how to enable Forms Based Authentication in claims mode. You can click on it to read more about how to set up FBA.
Here is a simple PowerShell script which changes the web app’s authentication mode to claims based:
$webApp = Get-SPWebApplication “/">http://<web-app>/ “
$webApp.UseClaimsAuthentication = "True";
Once you have executed the above PowerShell script, if you go to your web app’s authentication provider settings, you should see:
Clicking on Default, you will be able to select your identity provider for the claims based authentication:
If you are creating a new web app, you can initially choose which authentication mode you want: