How to Enable SNA Server IPX/SPX Clients to Use SPXII (138832)


The information in this article applies to:

  • Microsoft SNA Server 2.11, when used with:
    • the operating system: Microsoft Windows NT
This article was previously published under Q138832

SYMPTOMS

One of the protocols that the SNA Server client server interface uses is native IPX/SPX. SNA Server can be configured to talk over the improved SPXII protocol.

RESOLUTION

Microsoft has updated the file <SNAROOT>\SYSTEM\SNANW.DLL to correct this problem.

STATUS

This feature is included in the latest U.S. Service Pack for SNA Server for Windows NT, version 2.11. 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

An improved version of SPX is SPXII. SPXII has the following advantages:
  • SPXII can use the maximum packet size allowable by the network type. On an Ethernet LAN, for example, an SPX II packet can be a full 1518 bytes. Standard SPX is only capable of sending 576 byte packets.
  • SPXII can use "windowing" where multiple packets can be outstanding at one time. It uses negative acknowledgments (NAKs) to indicate that some packets were not received. Standard SPX allows only one packet to be outstanding at any time.
To enable the newer SPXII protocol to work with SNA Server, add the following subkey to the registry: 
   \Hkey_Local_machine
     \System
       \CurrentControlSet
         \Services
           \SnaBase
             \Parameters
                \SnaSpx
Then, add the following value: 
   SPXII:REG_SZ:yes
SPXII has been supported since SNA Server 2.1 with the addition of the registry entry, but only on Windows NT 3.5/3.51, not on Windows NT 3.1.

Client support is as follows:
  • Windows 95: Enable the same registry entry as above.
  • Windows NT: Enable the same registry entry as above.
  • Windows 3.x and MS-DOS: SPX-II is not Supported on these platforms.
Modification Type:MajorLast Reviewed:10/23/2003
Keywords:kbbug kbfix kbnetwork kbprogramming KB138832
©2003 Microsoft Corporation. All rights reserved.