SNA Clients Experience Delay Connecting to Multihomed Server (182332)
The information in this article applies to:
- Microsoft SNA Server 3.0 SP2
- Microsoft SNA Server 4.0
This article was previously published under Q182332 SYMPTOMS
SNA Server clients configured to use TCP/IP sockets may experience
a delay
during the initial connection to a multihomed SNA Server computer.
The time
delay before getting the application session depends upon the
TCP/IP retry
timers configured on the client, but should be 45 to 55 seconds
assuming
the retry-timer settings have not been modified from their
defaults.
CAUSE
Multihomed server support was added to SNA Server and SNA Server
clients in
SNA Server 3.0 Service Pack 2. This new feature allows the SnaBase
service
to send two entries (a new entry, TCPIP2, that lists all IP
addresses of
the server, and the original entry, TCPIP, that lists only one of
possibly
many IP addresses associated with the server) in its service-table
updates
for the TCP/IP transport. The original entry is retained for
backward
compatibility with earlier-version (pre-3.0 SP2) clients and
servers.
SNA Server 3.0 SP2 (and later) clients now receive all of the
TCP/IP
addresses configured on the SNA Server computer. However, the
clients try
to connect to the SNA Server computer by trying the TCP/IP
addresses in the
order they are listed in the service-table update received from
the SNA
Server computer. If the first TCP/IP address exists on a subnet
that is not
reachable from the client's subnet, the client is not able to try
the next
TCP/IP address in its list until the TCP/IP retry timers expire.
This can
lead to a 45 to 55 second delay between connection attempts over
the
different TCP/IP addresses.
Note: Once the initial connection is made, the SNA Server client
will
continue to use the correct TCP/IP address for the duration of the
application session. The potential delay is only noticeable upon
the
initial application startup.
STATUS
Microsoft has confirmed this to be a problem in SNA Server versions 3.0
SP2 and 4.0. This problem was corrected in the latest SNA Server version 3.0 and 4.0 U.S. Service Packs. For information on obtaining this Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):
Modification Type: | Minor | Last Reviewed: | 9/22/2005 |
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Keywords: | kbHotfixServer kbQFE kbbug kbfix KB182332 |
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