Event ID 23, Qualifier 11 While Using Andrew or IBM Twinax Link

• Microsoft SNA Server, versions 2.0, 2.1, 2.11, and 2.11 SP1

SYMPTOMS

An SNA Server Twinax connection, after being active, will go into a "Pending" status in the SNA Server Administrator program. When this occurs, Event ID 23, Qualifier 11, is logged to the Application Event log. This can occur with both the Andrew and IBM Twinax Link services.

CAUSE

The problem is associated with a block of data inbound to the AS/400, which has a length of 1025 decimal. The Twinax line protocol has a maximum read/write length of 1024. This means the AS/400 asks for a block of 1024 characters and then a block of one character. It does the one-character block by setting the Address Counter Register and the Reference Counter Register to the same location and then performing a Read Between Limits Command. This should result in a one-character block being sent out on the Twinax line.

However, there is an incorrect register, which results in the Twinax Link service returning an error to the AS/400 of "Invalid Register Value." This causes the AS/400 to reset the Twinax line, which causes the outage.

This error occurs in both the Andrew and the IBM driver supplied with SNA Server.

RESOLUTION

Apply the fix referenced below. The fix is made to a routine called "DTPDCmdReadBetwLimits," which does the correct math locally to send the one-byte message instead of the invalid register value.

STATUS

Microsoft has confirmed this to be a problem in SNA Server versions 2.0, 2.1, 2.11, and 2.11 SP1. This problem was corrected in the latest Microsoft SNA Server 2.11 U.S. Service Pack. For information on obtaining the service pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K

MORE INFORMATION

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