DOCUMENT:Q262433  11-JUN-2000  [exchange]
TITLE   :XADM: Error Message: Event ID 1043 Source MSExchangeDS
PRODUCT :Microsoft Exchange
PROD/VER:winnt:5.5
OPER/SYS:
KEYWORDS:exc55

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The information in this article applies to:

 - Microsoft Exchange Server, version 5.5 
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SYMPTOMS
========

If the Knowledge Consistency Checker runs by default on a directory replication
server or if you start the Knowledge Consistency Checker (in the server
Directory Service properties, click Check Now on the General tab) on a server
that has directory replication connectors to other sites, the following error
message is logged in the Microsoft Windows NT Event Viewer application event
log:

   Event ID: 1043
   Source: MSExchangeDS

   Type: Error
   Category: Knowledge Consistency Description:
   The knowledge consistency checker has detected that site
   /O=Organization/OU=Site can be replicated to this directory service from more
   than one source. Remove one source and run the knowledge consistency checker
   again. c1030b0f

CAUSE
=====

This issue can occur if the directory replication connectors are set up in a
configuration that creates a message loop between the directory replication
servers within the Exchange Server organization. The Knowledge Consistency
Checker detects duplicated knowledge of Exchange Servers through the duplicate
directory replication connectors.

For example, if you have Site A, Site B, and Site C set up with directory
replication connectors as follows

 - Site A <==> Site B

 - Site B <==> Site C

 - Site C <==> Site A

this setup creates a logical loop for the directory replication messages and
generates the Knowledge Consistency Checker error message.

RESOLUTION
==========

To resolve this issue, remove one of the directory replication connectors that
creates the loop between the sites.

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

Each Exchange Server computer in a site runs a Knowledge Consistency Checker
check every three hours to verify the Exchange Server computer's knowledge of
other Exchange Server computers in the site. To verify this knowledge, the
Exchange Server computer contacts another Exchange Server computer in the site
to compare information. Which Exchange Server computer is contacted depends on
the server's alphanumeric name. The Knowledge Consistency Checker is remote
procedure call (RPC) based and operates only within the site.

Additional query words: kcc

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Keywords          : exc55 
Technology        : kbExchangeSearch kbExchange550 kbZNotKeyword2
Version           : winnt:5.5
Issue type        : kbprb

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