Understanding NWLink
Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2
Understanding NWLink
The NWLink IPX/SPX/NetBIOS Compatible Transport Protocol (NWLink) is a Network Driver Interface Specification (NDIS)-compliant, native 32-bit implementation of Novell's IPX/SPX protocol. NWLink supports two networking application programming interfaces (APIs): NetBIOS and Windows Sockets. These APIs allow communication among computers running Windows and between computers running Windows and NetWare servers.
The NWLink transport driver is an implementation of the lower-level NetWare protocols, which include IPX, SPX, RIPX (Routing Information Protocol over IPX), and NBIPX (NetBIOS over IPX). IPX controls addressing and routing of packets of data within and between networks. SPX provides reliable delivery through sequencing and acknowledgments. NWLink provides NetBIOS compatibility with a NetBIOS layer over IPX.
Interoperating with NetWare resources
Depending on what platform you are using and what resources that you want to access, you may need to use NWLink in conjunction with other tools. The following table lists several interoperability options that use NWLink.
| Platform | Running | Can connect to |
|---|---|---|
Windows |
NWLink |
Client/server applications running on a NetWare server |
Windows |
NWLink and Client Service for NetWare |
NetWare servers for file and print services |
NetWare client |
IPX with NetBIOS, Named Pipes, or Windows Sockets support |
Computers running Windows (with NWLink installed) running IPX applications such as Microsoft SQL Server |
NetWare client |
IPX |
Servers running Windows Server 2003 (with NWLink installed) for file and print services |
For a Windows client to access file and print resources on a NetWare server, Client Service for NetWare must be installed on the Windows client in addition to NWLink. For more information, see Novell NetWare integration overview.
Interoperating with Microsoft resources
By default, the file and print sharing components of Windows use NetBIOS over IPX to send file and print sharing messages.
Alternatively, you can disable NetBIOS so that the file and print sharing messages are sent directly over IPX. This is known as direct hosting. While direct hosting may be more efficient, it causes an interoperability issue: A direct hosting client can only connect to a direct hosting server. Direct hosting clients include computers running Microsoft Network Client for MS-DOS, Windows for Workgroups, Windows 95, and Windows 98. Direct hosting servers include computers running Microsoft Network Client for MS-DOS, and all Windows-based computers.
The following table lists several interoperability options that use IPX.
| Platform | Running | Can connect to |
|---|---|---|
Microsoft Network Client for MS-DOS Windows for Workgroups Windows 95 Windows 98 |
IPX only (direct hosting) |
File and print shared resources on computers running: Microsoft Network Client for MS-DOS Windows for Workgroups Windows 95 Windows 98 Windows NT Windows 2000 |
Microsoft Network Client for MS-DOS Windows for Workgroups Windows 95 Windows 98 Windows NT Windows 2000 |
NetBIOS over IPX |
File and print shared resources on computers running: Microsoft Network Client for MS-DOS Windows for Workgroups Windows 95 Windows 98 Windows NT Windows 2000 |
Important
You cannot use direct hosting of IPX to gain access to resources on any computer acting as a direct host server from a computer running Windows. Computers running Windows do not include a direct hosting client for NWlink. For example, while you can connect by using direct hosting of IPX to resources on a computer running Windows from a computer running Windows 95 or Windows 98 (where NetBIOS is disabled by default for performance reasons), you cannot connect by using direct hosting of IPX to the computer running Windows 95 or Windows 98 from the computer running Windows. For detailed instructions about enabling direct hosting, see Enable direct hosting of IPX.
Client Service for NetWare is not available on 64-bit versions of Windows Server 2003 and Windows XP.
Gateway Service for NetWare is included in Windows 2000 Server. It is not included in the Windows Server 2003 family.
Computers running operating systems in the Windows Server 2003 family cannot be IPX routers.