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For a Microsoft .NET Framework version 1.1 version of this article, see 839424.
When you add members to an Active Directory directory services group that already contains more than 1000 members, the group membership list becomes truncated to 1000 members plus the newly added members.
Note On a computer that is running Microsoft Windows Server 2003, the group membership becomes truncated to 1500 members plus the newly added members.
The System.DirectoryServices namespace contains a flaw that may cause the group membership list to become truncated if new members are added to a group that already contains more than 1000 members.
This problem occurs when you use the DirectoryEntry::Properties.Add method. By default, the Lightweight Directory Access Protocol (LDAP) server responds to a request to return data for multi-valued attributes by returning only the first 1000 values. (On Windows Server 2003, the LDAP returns the first 1500 values.)
To obtain the whole list of values, an application must use a concept that is known as range retrieval. Range retrieval is a process of obtaining the members in a set of partial lists. However, the System.DirectoryServices.DirectoryEntry object does not use range retrieval when retrieving multi-valued attributes. Therefore, you never receive more than 1000 members for a group, or 1500 members in Windows Server 2003, when you access the DirectoryEntry::Properties["member"] attribute of a group.
When you use the DirectoryEntry::Properties["attribute"].Add method to add values to a multi-valued attribute, you are essentially adding a new value to the existing values that are cached internally in a property cache. Another later call to the DirectoryEntry::CommitChanges method causes the server to overwrite the whole multi-valued attribute with the values that are in the cache.
Because the System.DirectoryServices namespace retrieved only 1000 or 1500 of the values, any server-side values that were not returned are removed from the multi-valued attribute during the overwrite process. In the "member" attribute of a group, this behavior causes all group members over the 1000-value limit or the 1500-value limit to be removed from the group membership.
Software Update Information
A supported software update is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This software update may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Microsoft .NET Framework 1.0 service pack that contains this software update.
To resolve this problem immediately, contact Microsoft Product Support Services to obtain the software update. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:
Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.
You must have the .NET Framework 1.0 installed to apply this software update.
You do not have to restart your computer after you apply this software update.
Software Update Replacement Information
This software update does not replace any other software updates.
The English version of this software update has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.
Date Time Version Size File name ---------------------------------------------------------------------- 24-Mar-2004 07:02 1.0.3705.492 86,016 System.directoryservices.dll
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For additional information about the terminology that is used to describe Microsoft product updates, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates