The NWLink IPX/SPX/NetBIOS Compatible Transport Protocol (usually referred to as NWLink) is Microsoft's implementation of Novell's NetWare Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX) protocol. NWLink is most commonly used in environments in which clients running Microsoft operating systems are used to access resources on NetWare servers, or in which clients running NetWare are used to access resources on computers running Microsoft operating systems.
NWLink allows computers running Windows XP Professional to communicate with other network devices that are using IPX/SPX. NWLink also can be used in small network environments that use only clients running Windows XP Professional and other Microsoft operating systems.
NWLink supports the networking application programming interfaces (APIs) that provide the interprocess communication (IPC) services described in Table 4.8.
Table 4.8 Networking APIs Supported by NWLink
Supports existing NetWare applications written to comply with the NetWare IPX/SPX Sockets interface
NetBIOS over IPX
Implemented as NWLink NetBIOS; supports communication between a NetWare client running NetBIOS and a computer running Windows XP Professional and NWLink NetBIOS
NWLink also provides NetWare clients with access to applications designed for Windows 2000 Server, such as Microsoft SQL Server and Microsoft SNA Server. To provide NetWare clients access to file and print resources on a computer running Windows 2000 Server, you should install File and Print Services for NetWare (FPNW).
In summary, the 32-bit Windows XP Professional implementation of NWLink provides the following features:
The procedure for installing NWLink is the same process used to install any network protocol in Windows XP Professional.
To install NWLink, complete the following steps:
The Select Network Component Type dialog box appears.
The Select Network Protocol dialog box appears.
Figure 4.8 The Select Network Protocol dialog box
NWLink configuration involves three components: frame type, network number, and internal network number. By default, Windows XP Professional detects a frame type and a network number automatically when you install NWLink. Windows XP Professional also provides a generic internal network number. However, you must specify an internal network number manually if you plan to run FPNW or IPX routing, as shown in Figure 4.9.
Each network adapter card bound to NWLink in a computer requires a frame type and network number.
Figure 4.9 Configuring NWLink
A frame type defines the way the network adapter card formats data. To ensure proper communication between a computer running Windows XP Professional and a NetWare server, you must configure the NWLink frame type to match the frame type on the NetWare server.
A connection between two computers that use different frame types is possible if the NetWare server is acting as a router. However, this is inefficient and can result in a slow connection.
Table 4.9 lists the topologies and frame types supported by NWLink.
Table 4.9 Topologies and Frame Types Supported by NWLink
Ethernet II, 802.3, 802.2, and Subnetwork Access Protocol (SNAP), which defaults to 802.2
802.5 and SNAP
Fiber Distributed Data Interface (FDDI)
802.2 and SNAP
On Ethernet networks, the standard frame type for NetWare 2.2 and NetWare 3.11 is 802.3. For NetWare 3.12 and later, the default is 802.2.
When you install NWLink, Windows XP Professional automatically determines which IPX frame type is in use on the network and sets the NWLink frame type accordingly. If Windows XP Professional detects frame types in addition to 802.2 during NWLink installation, the frame type for NWLink defaults to 802.2.
Each frame type configured on a network adapter card requires a network number, which must be unique for each network segment. All computers on a segment using the same frame type must use the same network number to communicate with one another.
On a computer running Windows XP Professional, type ipxroute config at a command prompt to display the network number, frame type, and device in use.
Although Windows XP Professional automatically detects a network number during NWLink installation by default, you can also specify a network number manually by using the Registry Editor.
Setting a network number in the registry for a given frame type requires entering two corresponding entries, NetworkNumber and PktType, in the HKEY_LOCAL_ MACHINE\SYSTEM\CurrentControlSet\Services\ Nwlnkipx\Parameters\Adapters\Adapter subkey of the registry.
NetworkNumber specifies the network number (in hexadecimal) for the adapter. If the value for this entry is 0, NWLink gets the network number from the network while it is running. Network numbers are 4 bytes (eight hexadecimal characters). The NetworkNumber entry takes a REG_MULTI_SZ data type.
If an adapter uses multiple packet types, you can specify the network number for each packet type by adding corresponding values in the NetworkNumber entry.
PktType specifies the packet form to use. The PktType entry takes a REG_MULTI_SZ data type. Table 4.10 lists the values for the PktType entry and the packet forms supported by NWLink.
Table 4.10 Packet Types or Forms Supported by NWLink
In most cases you should use Auto Detect. You should configure the frame type and network number manually only if Auto Detect does not work in your environment.
An internal network number uniquely identifies a computer on the network for internal routing. This eight-digit hexadecimal number, or virtual network number, is set to 00000000 by default.
The internal network number identifies a virtual network segment inside the computer. That is, it identifies another (virtual) segment on the network. Therefore, if an internal network number is configured for a computer running Windows XP Professional, a NetWare server or a router adds an extra hop in its route to the computer.
You must manually assign a unique, nonzero internal network number in the following situations:
If a computer has multiple network adapter cards bound to NWLink, and if you want each to use a different frame type, configure each network adapter card to use the Manual Frame Type Detection option. You also must specify a frame type, network number, and internal network number for each network adapter card.
Windows XP Professional provides several tools to help you resolve NetWare connectivity problems, including those listed in Table 4.11.
Table 4.11 Troubleshooting Tools for NetWare Connectivity Problems
Type this command in a command prompt to determine information about the current state of the stack. It displays the current IPX status, including the network number, MAC address, interface name, and frame type.
Type ipxroute ripout #### (where #### is an eight-digit hexadecimal number, the network number) to determine whether there is a connection to a specific network.
Allows you to detect and troubleshoot problems on LANs and on wide area networks (WANs). Network Monitor helps you identify network traffic patterns and problems.
Connection problems are usually caused by incorrect configuration settings for NWLink. The following sections include several common configuration problems that you should check when you are having problems connecting to a NetWare server from a client running Windows XP Professional.
For a client running Windows XP Professional to access a NetWare server, you must install NWLink and Client Services for NetWare on the client, and Client Services for NetWare must be running.
To verify that NWLink and Client Services for NetWare are installed, complete the following steps:
To verify that Client Services for NetWare is running, complete the following steps:
For a client running Windows XP Professional to access a NetWare server, the frame type should be configured to Auto Detect.
To verify the frame type on the client is set to Auto Detect, complete the following steps:
The Local Area Connection Status dialog box appears.
The Local Area Connection Properties dialog box appears.
For a client running Windows XP Professional to access a NetWare server, the frame type and network number must be configured to match the NetWare server.
To determine the installed network number and frame type on the client, complete the following steps:
In this practice, you'll install and configure the NWLink IPX/SPX/NetBIOS Compatible Transport Protocol. Then you'll install and configure NWLink. With multiple protocols installed, you'll change the binding order of a protocol, unbind a protocol from a network adapter card, and remove NWLink from a computer.
After completing this practice, you will be able to
To complete this practice, you need
You can install any of the available protocols in Windows XP Professional using this procedure.
Run the NWLink file in the Demos folder on the CD-ROM accompanying this book for a demonstration of installing and configuring NWLink.
Windows XP Professional displays the Local Area Connection Properties dialog box, which shows the network adapter card in use and the network components used in this connection.
Windows XP Professional displays the Select Network Component Type dialog box.
Windows XP Professional displays the Select Network Protocol dialog box.
What protocols can you install?
Windows XP Professional displays the Local Area Connection Properties dialog box.
What type of frame detection is selected by default?
Notice that when the default frame type is selected, the Network Number option is not active.
What other frame types are listed?
Why is the Network Number option now active?
What is the network number and frame type for the LAN?
Here are some questions to help you determine whether you have learned enough to move on to the next lesson. If you have difficulty answering these questions, review the material in this lesson before beginning the next lesson. The answers are in Appendix A, "Questions and Answers."