Q136151: SFM Print Service is Limited to 127 Printers

Article: Q136151
Product(s): Microsoft Windows NT
Version(s): winnt:3.51,4.0
Operating System(s): 
Keyword(s): kbprint kbPrinting
Last Modified: 07-SEP-2001

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The information in this article applies to:

- Microsoft Windows NT Server versions 3.51, 4.0 
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SYMPTOMS
========

Macintosh clients cannot print to printers shared by Windows NT Services for
Macintosh (SFM) print servers. The following error message appears on the
Macintosh client:

  A communication error has occurred.

The following error is logged in the event log on the Windows NT SFM Server:

  Macprint Event ID 2019 - Semaphore timeout.

Macintosh clients may also be unable to see the shared SFM printers. Also, you
may receive the following event ID:

  Event ID 10022

This can occur when more than 127 AppleTalk-connected printers are configured as
target printers regardless if the Windows NT Appletalk printers are being
accessed by Macintosh clients. When this occurs, print jobs queued to the
AppleTalk printers are stalled.

CAUSE
=====

This problem is caused by an AppleTalk Printer Access Protocol (PAP)
limitation.

In response to a connection request from a Macintosh client, Windows NT sends the
socket on which the client can respond. When there are more than 127 printers
shared on a Windows SFM server, Windows NT will exhaust the range of available
sockets on the first node, and then move to the next node (a node is a set of
sockets.) But there is no provision in the protocol to tell the client which
node to use. The client continues to use the first node, but uses the new
socket. That pair corresponds to some other printer, which drops the request and
causes the errors.

This is a limitation in Apple's design of Appletalk.

WORKAROUND
==========

A workaround exists that involves creating a service account specifically for
Print Services for Macintosh and then denying that account access to certain
printers using the Control Panel Printers tool. This will disallow Print
Services for Macintosh access to share specified printers for Macintosh clients
only.

To accomplish this, perform the following steps:

1. On the Windows NT SFM server, create an account in User Manager to use as a
  service account for Print Services for Macintosh. Click to clear the "User
  must change password at next logon" checkbox and select the Password never
  expires checkbox. Specify a desired password.

2. Start the Control Panel Services tool. Click Startup for Print Services for
  Macintosh. Click This account and specify the macprint account and password
  information created in Step 1.

3. Start the Control Panel Printers tool. Right-click on the printer(s) that SFM
  should not share. Click Properties, and then click the Security tab. Click
  Permissions, and then select No Access for the macprint account.

Additional query words: MAC sfmprint

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Keywords          : kbprint kbPrinting 
Technology        : kbWinNTsearch kbWinNT351search kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS351 kbWinNTS351search
Version           : winnt:3.51,4.0
Issue type        : kbprb

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