无法从服务器访问目录服务 - DirectoryServicesCOMException

Question

我正在尝试在Windows Server 2008 R2（已安装IIS7）上运行的ASP.Net（4.0）应用程序中查询AD。在本地计算机（Windows 7）上运行正常，但在服务器上运行不正常。我正在尝试获取当前用户的用户标识。我看过类似问题的Q＆amp; A，但没有成功。

这是代码片段......

public partial class Default : System.Web.UI.Page
    {
        PrincipalContext principalCtx = new PrincipalContext(ContextType.Domain);
        UserPrincipal currentUser = UserPrincipal.Current;

web.config有

<authentication mode="Windows"/>
<identity impersonate="true" />

这是错误＆amp;堆栈跟踪...

[DirectoryServicesCOMException (0x80072020): An operations error occurred.
]
   System.DirectoryServices.DirectoryEntry.Bind(Boolean throwIfFail) +781
   System.DirectoryServices.DirectoryEntry.Bind() +44
   System.DirectoryServices.DirectoryEntry.get_AdsObject() +42
   System.DirectoryServices.PropertyValueCollection.PopulateList() +29
   System.DirectoryServices.PropertyValueCollection..ctor(DirectoryEntry entry, String propertyName) +119
   System.DirectoryServices.PropertyCollection.get_Item(String propertyName) +163
   System.DirectoryServices.AccountManagement.PrincipalContext.DoLDAPDirectoryInitNoContainer() +541617
   System.DirectoryServices.AccountManagement.PrincipalContext.DoDomainInit() +51
   System.DirectoryServices.AccountManagement.PrincipalContext.Initialize() +141
   System.DirectoryServices.AccountManagement.PrincipalContext.get_QueryCtx() +42
   System.DirectoryServices.AccountManagement.Principal.FindByIdentityWithTypeHelper(PrincipalContext context, Type principalType, Nullable`1 identityType, String identityValue, DateTime refDate) +27
   System.DirectoryServices.AccountManagement.Principal.FindByIdentityWithType(PrincipalContext context, Type principalType, IdentityType identityType, String identityValue) +146
   System.DirectoryServices.AccountManagement.UserPrincipal.FindByIdentity(PrincipalContext context, IdentityType identityType, String identityValue) +44
   System.DirectoryServices.AccountManagement.UserPrincipal.get_Current() +390

我尝试将IIS应用程序池作为NetworkService和ApplicationPoolIdentity运行，并且没有用。

有什么想法吗？感谢。