Common User ID Problem when Using Associated Printer Feature (195063)

SYMPTOMS

A user is able to access a 3270 display logical unit (LU) from a client workstation even though its associated printer LU is in use on a different client workstation. This problem occurs in the following scenarios:

Users connect to SNA Server using a common User ID. -or-
Users are validated using Windows NT's Guest account.

The Common User ID Scenario

SNA Server is configured with a 3270 LU pool. Each 3270 display LU in the pool is configured to have an associated printer LU assigned to it.

All of the users that connect to the SNA Server for access to the 3270 LU pool use a common user ID called SNAUSER.

When a user connects to the SNA Server using the SNAUSER ID and gets a 3270 display LU from the 3270 LU pool called DISP1 and its associated printer called PRT1, if this user closes the DISP1 display session in the 3270 emulator but leaves the PRT1 printer session open, another user from a different workstation using the SNAUSER ID may get the DISP1 display session when they request a 3270 display LU even though this display LU's associated printer is still in use on the first client workstation.

The Guest Account Scenario

SNA Server is configured with a 3270 LU pool. Each 3270 display LU in the pool is configured to have an associated printer LU assigned to it. The 3270 LU pool is assigned to the Everyone group in SNA Server Manager.

If users connect to the SNA Server system using the Guest account, or an account that is not defined on the Windows NT Server or Domain, the user will be validated using the Guest account if it is enabled on the Windows NT system. At this point, all of the users are using the same user account, therefore, the problem described in the earlier example can occur.

CAUSE

Starting with SNA Server 3.0 Service Pack 2 (SP2), the SNA Server would not allow a user to open a 3270 display LU if its associated printer was in use by another user. However, this did not take into account cases where multiple users connect to an SNA Server using a common user ID. SNA Server only checks the user ID requesting access to a 3270 display LU, and not where the request was being made from.

The change made in SNA Server 3.0 SP2 is described in the following Knowledge Base article:

172637 User Able to Open Display Session If Associated Printer in Use

Prior to SNA Server 3.0 SP2, any user could open a 3270 display LU even though the associated printer LU was in use.

RESOLUTION

SNA Server 3.0

To resolve this problem, obtain the latest service pack for SNA Server version 3.0. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

184307 How to Obtain the Latest SNA Server Version 3.0 Service Pack

SNA Server 4.0

This problem was corrected in the latest SNA Server version 4.0 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

MORE INFORMATION

After applying the update, SNA Server will not assign the user a 3270 display LU from a pool with an associated printer session that is currently in use, unless the printer session is in use by the same user, connected from the same client workstation.

Please refer to the SNA Server documentation for more details on the Associated Printer feature.