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Q162769: Wrong CNAME RR Causes DNS Startup and Zone Transfer Failure

Article: Q162769
Product(s): Microsoft Windows NT
Version(s): WINNT:4.0
Operating System(s): 
Keyword(s): kbnetwork
Last Modified: 09-AUG-2001

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The information in this article applies to:

- Microsoft Windows NT Server version 4.00 
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SYMPTOMS
========

If a Windows NT 4.0 DNS server contains an invalid CNAME RR record (see RFC
1034), the following two problems may occur:

- On a computer running Windows NT 4.0, you receive the following error when
  you attempt to use a "net start DNS" command:

  System error 13 has occurred. The data is invalid.

- BIND to a Windows NT zone transfer does not complete. The event log only
  shows the following message:

     Zone transfer is in progress.

CAUSE
=====

This problem is caused by the following invalid Resource Record that is
originally coming from a Digital UNIX server running BIND DNS 4.9.4-P1:

  name     IN A  x.x.x.x
           IN CNAME name-xxx.xxx.xx.xxx.xxxxxx.xxx

RESOLUTION
==========

Remove the invalid CNAME RR.

STATUS
======

Microsoft has confirmed this to be a problem in Windows NT version 4.0. We are
researching this problem and will post new information here in the Microsoft
Knowledge Base as it becomes available.

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

While Windows NT shows the invalid entry by line number (DNS event ID 203: DNS
server could not parse database file x line number y), BIND to Windows NT zone
transfer does not generate an error, but does not complete either. In a network
trace, you see Windows NT TCP resetting the connection during zone transfer.

BIND to BIND zone transfer reports this CNAME record as invalid, but still
completes the zone transfer.

See RFC 1034 for more information about CNAME Resource Records. The following is
an excerpt from RFC 1034:

  The domain system provides such a feature using the canonical name (CNAME)
  RR. A CNAME RR identifies its owner name as an alias, and specifies the
  corresponding canonical name in the RDATA section of the RR. If a CNAME RR is
  present at a node, no other data should be present; this ensures that the
  data for a canonical name and its aliases cannot be different. This rule also
  insures that a cached CNAME can be used without checking with an
  authoritative server for other RR types.

Additional query words: domain name system request comments comment
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Keywords          : kbnetwork 
Technology        : kbWinNTsearch kbWinNTSsearch
Version           : WINNT:4.0
Issue type        : kbbug
Solution Type     : kbpending

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