SNA NT Clients Should not Fall Back to Named Pipes (178126)

SYMPTOMS

When using a Windows NT SNA Server Client configured to use TCP/IP sockets connection against SNA Server, the client will try to using named pipes if the TCP connection fails. This behavior may need to changed in order to prevent extra network traffic. The use of named pipes may result in extra network traffic. For more information, please see the following article in the Microsoft Knowledge Base:

128985 Comparing SNA client TCP/IP named pipes vs sockets

One sign that the client has switched to named pipes is if the initial client connection takes 45 to 60 seconds to complete. This is usually the time required for the default TCP/IP retry timers to expire.

STATUS

Microsoft has confirmed this to be a problem in SNA Server versions 2.1, 2.11 SP1, 2.11 SP2, 3.0, 3.0 SP1, and 3.0 SP2.

This problem was corrected in the latest SNA Server version 3.0 U.S. Service Pack. For information on obtaining this Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

S E R V P A C K

A supported fix for SNA Server version 2.11 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.

MORE INFORMATION

This function is By Design for the Windows NT SNA Server Client. However, a hotfix is available that allows this function to be disabled by adding the following registry parameter:

   HKEYLOCALMACHINE\SYSTEM\CurrentControlSet\Services\SnaBase\Parameters\ 
   IgnorenamedPipes:REG_DWORD:0|1,

The default is 0 (1 = Never use named pipes)

Note: The hotfix must first be applied.