DOCUMENT:Q149819  26-JUN-1996  [winnt]
TITLE   :RPC Causes Exchange Server to Hang All Connected Clients
PRODUCT :Microsoft Windows NT  |  Microsoft Exchange Server
PROD/VER:3.51  | 4.00
OPER/SYS:WINDOWS
KEYWORDS:kbnetwork kbbug3.51

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The information in this article applies to:

 - Microsoft Windows NT Workstation version 3.51
 - Microsoft Windows NT Server version 3.51
 - Microsoft Exchange Server, version 4.0
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SYMPTOMS
========

All Microsoft Exchange clients connected to a Microsoft Exchange server 
periodically hang for several minutes. If the clients are left alone, then 
they will all resume normal operation without loss of data.

This symptom occurs sporadically.

CAUSE
=====

The Microsoft Exchange server received only part of the Remote Procedure Call 
(RPC) data sent by a Microsoft Exchange client and is waiting for the 
remaining part.

If a busy Microsoft Exchange server receives RPC data from a Microsoft 
Exchange client, and it accepts a part of the RPC fragment but not the entire 
amount, then if the client is rebooted or powered off before the remainder of 
the fragment is sent, the server can stop processing all RPC requests until 
the network transport detects the client failure and terminates the connection. 
If you use a "patient" transport protocol such as TCP/IP, this may take up to 
five minutes.

RESOLUTION
==========

Obtain the fix mentioned below or wait for the next Windows NT service pack.

STATUS
======

Microsoft has confirmed this to be a problem in Windows NT version 3.51. A 
supported fix is now available, but has not been fully regression-tested 
and should be applied only to systems experiencing this specific problem. 
Unless you are severely impacted by this specific problem, Microsoft 
recommends that you wait for the next Service Pack that contains this fix.
Contact Microsoft Product Support Services for more information.

This hotfix has been posted to the following Internet location:

   ftp://ftp.microsoft.com/bussys/
       winnt/winnt-public/fixes/usa/nt351/hotfixes-postsp4/rpclts3-fix

KBCategory: kbnetwork kbbug3.51
KBSubcategory: ntnetserv
Additional reference words: prodnt 3.51 4.00 exchng

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