DOCUMENT:Q158989  17-AUG-2001  [exchange]
TITLE   :XADM: Factors affecting Exchange Directory Replication Speed
PRODUCT :Microsoft Exchange
PROD/VER::4.0,5.0,5.5
OPER/SYS:
KEYWORDS:exc4 exc5 exc55

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The information in this article applies to:

 - Microsoft Exchange Server, versions 4.0, 5.0, 5.5 
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SUMMARY
=======

This article describes some of the reasons why Microsoft Exchange Server
Directory Replication can take longer than expected.

MORE INFORMATION
================

The following are factors that could affect the speed of Directory Replication
within Microsoft Exchange Sites as well between Sites.

1. Check the Microsoft Exchange Server Message Transfer Agent(MTA) queues to
   make sure that messages are flowing out of the queues at a reasonable rate.
   Directory Replication between Sites is message based and if messages are not
   flowing, Directory Replication will not take place. If the MTA is bogged down
   with messages, this maybe be due to excessive processor load, insufficient
   hardware, or insufficient memory, among other reasons.

2. Check the load on the sending and receiving Microsoft Exchange Servers. This
   can be done using the Windows NT Performance Monitor and looking at the
   %Processor Time counter of the Processor Object. If the %Processor Time is
   consistently high (above 80%) determine which process is useing most of the
   CPU cycles.

   If possible, stop the CPU intensive processes until the Directory Replication
   is complete. Make sure that you are not running CPU intensive programs, like
   an OpenGL screen saver (like Pipes), that may unnecessarily take up CPU
   cycles.

   It is beneficial to run Performance Monitor from a computer other than the one
   you are monitoring. This will allow you to catch screen saver processes
   running on the Microsoft Exchange Server computer.

3. If the number of addresses being replicated is very large, do not repeatedly
   manually request an update of all entries in the Global Address List.

4. Check the replication schedule. For the purpose of getting the replication
   done as soon as possible, it may be advisable to set the replication schedule
   to Always.

5. Check the topology of your Microsoft Exchange Organization. It may be
   possible that changes made to the Directory take a while to propagate to all
   parts of the Organization, if the number of intermediate hops is large.

   For more information on this issue, please refer to the following Microsoft
   Knowledge Base article:

   Q148381 XADM: Directory Replication Takes Too Long

Additional query words:

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Keywords          : exc4 exc5 exc55 
Technology        : kbExchangeSearch kbExchange500 kbExchange550 kbExchange400 kbZNotKeyword2
Version           : :4.0,5.0,5.5

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