DOCUMENT:Q157691  09-APR-1999  [exchange]
TITLE   :XADM: TNS Resolution Causes Buffer Overflow
PRODUCT :Microsoft Exchange
PROD/VER:winnt:4.0
OPER/SYS:
KEYWORDS:kbusage

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The information in this article applies to:

 - Microsoft Exchange Server, version 4.0 
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SYMPTOMS
========

Federal sites needing to use Tactical Name Service (TNS) instead of Domain Name
Service (DNS), will encounter the following issue. When Microsoft Exchange looks
to connect to another SMTP server, it queries the TNS for an MX Record (SMTP
address). If the address is present, everything works fine. If the address is
not present, the TNS server sends its own IP address. If the Server hardware is
an old UNIX computer, with a total input buffer of 200k, the Microsoft Exchange
mail headers will cause a buffer overflow.

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

Basic TNS information:

1. It is run on a special version of UNIX that the U.S. ARMY developed.

2. It includes only 1 zone.

3. It only listens on one IP address.

4. It dynamically registers hosts.

5. It does not support MX priority/preference values.

6. It does not support SOA records.

STATUS
======

Microsoft has confirmed this to be a problem in Microsoft Exchange Server
version 4.0. This problem was corrected in the latest Microsoft Exchange Service
Pack. For information on obtaining the Service Pack, query on the following word
in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K


Additional query words:

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Keywords          : kbusage 
Technology        : kbExchangeSearch kbExchange400 kbZNotKeyword2
Version           : winnt:4.0

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