Backup Config. Server May Not Always Read Local Config. File (163073)
The information in this article applies to:
- Microsoft SNA Server 2.0
- Microsoft SNA Server 2.1
- Microsoft SNA Server 2.11
- Microsoft SNA Server 2.11 SP1
This article was previously published under Q163073 SYMPTOMS
If the SNA Server service is configured to start automatically on a backup
configuration server and the SnaBase broadcast from the primary
configuration server has not yet been received, SNA Server may read its
configuration entries from another backup server's configuration file
instead of the local Com.cfg file. This will likely cause no problems, but
it may be inefficient.
If the SNA Server service encounters a network error while reading its
configuration file entries from another backup server or from the primary
configuration server, the following error occurs (though the Windows NT
Server return code may vary):
Event ID: 351
Source: SNA Server
Description: Error trying to read from \\server\COMCFG\COM.CFG (rc=995)
Windows NT Server return code 995 = ERROR_IO_INCOMPLETE.
This may indicate a problem with the underlying network. The above error
occurred at a site where the primary configuration server was located
across an IP router from the SNA Server. The IP router was acting as a
"black hole router," which was causing the network session to fail
abnormally. For more information on "black hole routers," see the
following
article in the Microsoft Knowledge Base:
159211 Diagnoses and Treatment of Black Hole Routers
CAUSE
When the SnaBase service starts on SNA Server, it listens for "service
table" broadcast announcements from other SnaBase services running on
other
computers running SNA Server in the SNA subdomain. This broadcast message
indicates the SNA Server services running on the server, the server's role
in the SNA domain, and other attributes.
The SnaBase service (on backup and member configuration servers) keeps
track of the "preferred" location for the SNA Server configuration file
for
the subdomain. When the SNA Server service starts, it reads its
configuration entries from the configuration file located on the
"preferred" server.
If a broadcast is received from the primary configuration server, then the
primary server is always the preferred server. However, if the SnaBase has
not yet heard from the primary configuration server, a remote backup
server
is chosen as the preferred server, instead of the local backup
configuration file.
RESOLUTION
A backup configuration server now prioritizes the local Com.cfg file ahead
of other backup configuration servers, if the primary configuration server
announcement has not been received or if its SnaBase is not running.
STATUS
Microsoft has confirmed this to be a problem in Microsoft SNA Server
versions 2.0, 2.1, 2.11, and 2.11 Service Pack 1. This problem was corrected in the latest SNA Server version 2.11 U.S. Service Pack. For information on obtaining this Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):
| Modification Type: | Major | Last Reviewed: | 11/26/2003 |
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| Keywords: | KB163073 |
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