ActiveDirectoryMembershipProvider Performance

[Brett Rees]

I'm using the ActiveDirectoryMembershipProvider with
connectionProtection=Secure and attributeMapUsername=sAMAccountName to
authenticate users against our active directory and have run into a
performance issue. On my development machine everything works great but when
I put it on the production server the authentication process takes forever,
30+ seconds. My development machine is running XP Pro and we use Server 03
for production. On the production machine, if I remove the
attributeMapUsername=sAMAccountName from the config file and let it use the
default mapping, userPrincipalName, it works perfectly. Unfortunately, we do
not want to use the userPrincipalName.

Any ideas on what would cause this to happen? How can I fix this problem so
I can use the sAMAccountName and not the userPrincipalName?

My config settings:
<configuration>
<connectionStrings>
<add name="AdConnectionString"
connectionString="LDAP://foo.corp.com:389/DC=foo,DC=corp,DC=com"/>
</connectionStrings>

<system.web>
<authentication mode="Forms">
<forms name="FooAuth" loginUrl="login.aspx" protection="All" path="/"
timeout="20" slidingExpiration="true" />
</authentication>
<authorization>
<deny users="?"/>
<allow users="*"/>
</authorization>

<membership defaultProvider="AspAdMembershipProvider">
<providers>
<add
connectionStringName="AdConnectionString"
connectionUsername="fooUserName"
connectionPassword="fooPassword"
connectionProtection="Secure"
enablePasswordReset="false"
enableSearchMethods="false"
requiresQuestionAndAnswer="false"
applicationName="/"
clientSearchTimeout="30"
serverSearchTimeout="30"
attributeMapUsername="sAMAccountName"
name="AspAdMembershipProvider"
type="System.Web.Security.ActiveDirectoryMembershipProvider, System.Web,
Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/>
</providers>
</membership>
</system.web>
</configuration>