Microsoft KB Archive/261129

= DLC Connection Stays Pending Due to Bit-Flipped TEST Poll =

Article ID: 261129

Article Last Modified on 2/22/2007

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APPLIES TO


 * Microsoft SNA Server 4.0
 * Microsoft SNA Server 4.0 Service Pack 4
 * Microsoft Host Integration Server 2000 Standard Edition
 * Microsoft Host Integration Server 2000 Service Pack 1

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This article was previously published under Q261129



IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows Registry



SUMMARY
By default, during 802.2 connection startup, a computer that is running Microsoft SNA Server or Microsoft Host Integration Server 2000 (HIS) on an Ethernet network tests link station-to-link station connectivity by sending four LLC test commands (both 802.3 and DIX frame types to both the configured and bit-flipped Media Access Control [MAC] addresses). For additional information on this process, click the following article number to view the article in the Microsoft Knowledge Base:

123791 SNA Server remote station discovery process

In some environments, it may be necessary to force test commands to only be sent to one of these two addresses. A registry entry is available for controlling this process. For information on how to do this, see the &quot;More Information&quot; section.



MORE INFORMATION
WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

 Start Registry Editor (Regedt32.exe). Locate the following key in the registry:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\SNADLC?\Parameters\ExtraParameters

NOTE: SNADLC? is the link service used by the connection, and needs bit-flipped TEST polls disabled. On the Edit menu, click Add Value, and then add the following registry value:

Value Name: DisableFlipping

Data Type: REG_DWORD

Value: 1 (valid values are 0=enable both configured and bit-flipped addresses to be sent; or 1=send only bit-flipped address)

 Quit Registry Editor.

After a test response is received, the next step in the connection process is for SNA Server to send an XID request. SNA Server sends the XID request to the address in the first test response that it receives. In some environments, responses are received on both the configured and bit-flipped addresses. If the first response received is not from the intended mainframe device or AS/400 computer, SNA Server or HIS cannot establish a connection with that device, and the connection status stays pending.

