Forms Authentication You can use the normal forms authentication to authenticate a user against an Active Directory, for that you just need you AD connection string: <connectionStrings> <add name=”ADConn” connectionString=”LDAP://YourConnection” /> </connectionStrings> and add the Membership Provider to use this connection: <membership defaultProvider=”ADMembership”> <providers> <add name=”ADMembership” type=”System.Web.Security.ActiveDirectoryMembershipProvider, System.Web, Version=2.0.0.0, Culture=neutral, PublicToken=b03f5f7f11d50a3a” connectionStringName=”ADConn” connectionUsername=”domain/user” connectionPassword=”pwd” /> … Read more