AD and Forms Authentication - asp.net

Question

I'm trying to allow users to login with either forms authentication or their AD account but having some problems. I'm logged into an AD accountno,w but Page.User.Identity.Name is blank. I have this in my web.config:
<connectionStrings>
<add name="ADConnectionString" connectionString="LDAP://full.domain.address:389/DC=mydomain,DC=blah,DC=uk"/>
<add name="myapp" connectionString="Data Source=myserver;Initial Catalog=myapp;User ID=myapp;Password=myapp" providerName="System.Data.SqlClient"/>
</connectionStrings>
<system.web>
<authentication mode="Forms">
<forms loginUrl="~/Account/Login.aspx" timeout="129600" name="CookieMonster" protection="All" slidingExpiration="true" cookieless="UseCookies"/>
</authentication>
<membership defaultProvider="ADMembershipProvider">
<providers>
<clear/>
<add name="AspNetSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider"
connectionStringName="myapp" enablePasswordRetrieval="false" enablePasswordReset="true"
requiresQuestionAndAnswer="false" requiresUniqueEmail="false"
maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0"
passwordAttemptWindow="10" applicationName="/"/>
<add name="ADMembershipProvider" type="System.Web.Security.ActiveDirectoryMembershipProvider, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
connectionStringName="ADConnectionString"/>
</providers>
</membership>
<profile>
<providers>
<clear/>
<add name="AspNetSqlProfileProvider" type="System.Web.Profile.SqlProfileProvider" connectionStringName="myapp" applicationName="/"/>
</providers>
</profile>
Do I need to do something else to get this to work? I've tried logging in with my domain account and domain\myaccount to no avail.
When I try var u = Membership.GetUser("mydomain\\myuser"); I get an error: Usernames must not contain '\' when mapped to 'userPrincipalName'.

Answer 1

AD userPrincipalName might be something like user#full.domain.address. Try using the sAMAccountName value for the attributeMapUsername:
<add name="ADMembershipProvider"
type="System.Web.Security.ActiveDirectoryMembershipProvider, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
connectionStringName="ADConnectionString"
attributeMapUsername="sAMAccountName"/>
If you are unable to connect, you may need to add connectionUsername and connectionUserPassword attributes (check the MSDN documentation).

Answer 2

"sAMAccountName" does not include the domain. To resolve your problem, simply remove the domain qualifying form your username:
Instead of var u = Membership.GetUser("mydomain\\myuser");
use var u = Membership.GetUser("myuser");
This is because you specified the domain in the connection string, implicitly by connecting to a particular active directory.