Network Adapter Drivers and Protocols: The Basics

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This chapter describes technical issues related to network adapters and protocols for Windows 95, and also presents some technical notes and tips for networking.

A network adapter (sometimes called a network interface card, or NIC) is a hardware card installed in a computer so it can communicate on a network. The network adapter provides one or more ports for the network cable to connect to, and it transmits and receives data onto the network cable.

Every networked computer must also have a network adapter driver, which controls the network adapter. Each network adapter driver is configured to run with a certain type of network adapter.

A networked computer must also have one or more protocol drivers (sometimes called a transport protocol or just a protocol). The protocol driver works between the upper-level network software and the network adapter to package data to be sent on the network.

For two computers to communicate on a network, they must use identical protocols. Sometimes, a computer is configured to use multiple protocols. In this case, two computers need only one protocol in common to communicate. For example, a computer running File and Printer Sharing for Microsoft Networks that uses both NetBEUI and TCP/IP can communicate with computers using only NetBEUI or only TCP/IP.

In Windows 95, all network adapter drivers and protocols supporting protected-mode clients are configured by using the Network option in Control Panel rather than by manually editing configuration files. Configuration values are stored in the Registry.

On This Page

NDIS Driver Basics
Network Protocol Basics
Network Adapters and Protocols: The Issues
Network Adapters and Windows 95
IPX/SPX-Compatible Protocol
TCP/IP Protocol
Microsoft NetBEUI Protocol
Using WinPopup to Broadcast a Pop-Up Message
Troubleshooting Protocol Problems

NDIS Driver Basics

Windows 95 supports the Network Device Interface Specification (NDIS) versions 2.x and 3.1 protocol and adapter drivers, and provides an NDIS 3.1 replacement for version 3.0 drivers, which are incompatible with Windows 95.

By using NDIS 3.1 drivers, Windows 95 can support a wide range of network media, including Ethernet, token ring, and ArcNet®. The NDIS 3.1 specification accommodates Plug and Play features, so that in many cases network adapters can be added and removed dynamically while the computer is running. The related features and benefits are summarized in the following discussion.

Plug and Play support for network protocols and adapters.

Because of Plug and Play enhancements, the operating system can determine automatically the adapters to which each protocol should bind. If a Plug and Play event occurs, such as removing a PCMCIA network adapter from a portable computer, the NDIS 3.1 protocols and network adapter drivers remove themselves from memory automatically. (This Plug and Play capability is supported for most PCMCIA adapters, but not for most ISA adapters, which have power considerations.)

New NDIS mini-driver model.

The mini-driver provided by the adapter manufacturer implements only the half of the Media Access Control (MAC) layer functionality that is specific to the network adapter, which includes establishing communications with the adapter, turning on and off electrical isolation for Plug and Play, providing media detection, and enabling any value-added features the network adapter may contain.

The Windows 95 NDIS wrapper implements the half of the MAC functionality that is common to all NDIS drivers. The new mini-drivers are faster and roughly 40 percent smaller than earlier versions of NDIS 3.x network adapter drivers. The Windows 95 mini-drivers are also binary-compatible with Windows NT 3.5 mini-drivers, which means they can be used without recompiling. (You can recognize a mini-driver by its .SYS filename extension; other drivers have .VXD extensions.)

Real-mode NDIS 2 support.

An NDIS 2.x protocol under Windows 95 must use an NDIS 2.x network adapter driver. Both the protocol and network adapter drivers must load and bind in real mode before running for Windows 95. Values in PROTOCOL.INI are used to load the real-mode NDIS drivers, as described in Chapter 8, "Windows 95 on Microsoft Networks." However, you still use the Network option in Control Panel to configure NDIS 2 adapters.

When you run a real-mode network (for example, when using Safe Mode with Networking for system startup), Windows 95 uses NDIS 2 versions of NetBEUI and IPX/SPX protocols. These protocols are not intended for everyday use, since Windows 95 supplies faster protected-mode versions of these protocols. These real-mode protocols are also provided for client computers that start from a floppy disk and run a shared copy of Windows 95 from a server.

Windows 95 also supports existing ODI drivers with Novell® NetWare®-compatible network clients. For information, see Chapter 9, "Windows 95 on NetWare Networks."

Network Protocol Basics

Windows 95 network protocols are implemented as 32-bit, protected-mode VxDs that offer high performance and use no conventional memory. Windows 95 can support multiple protocols simultaneously, and protocol stacks can be shared among the installed network clients. For example, the IPX/SPX-compatible protocol can support both Client for NetWare Networks and Client for Microsoft Networks. The following protocols are included with Windows 95.

Microsoft IPX/SPX-compatible protocol.

This protocol is compatible with the Novell NetWare Internetwork Packet Exchange/Sequential Packet Exchange (IPX/SPX) implementation. Windows 95 includes both 32-bit, protected-mode and real-mode support for this protocol. This protected-mode protocol provides the following benefits:

  • Support for any Novell NetWare-compatible network client

  • Support for packet-burst mode to offer improved network performance

  • Support for the Windows Sockets, NetBIOS, and ECB programming interfaces

  • Support for automatic detection of frame type, network address, and other configuration settings

  • Connectivity with servers and workstations on NetWare or Windows NT Server 3.5 networks, and mixed networks

  • Routable for connectivity across all network bridges and routers configured for IPX/SPX routing

Microsoft TCP/IP.

This is a complete implementation of the standard, routable Transmission Control Protocol/Internet Protocol (TCP/IP) protocol. Windows 95 includes only protected-mode support for this protocol. Microsoft TCP/IP provides the following benefits:

  • Support for Internet connectivity and the Point-to-Point Protocol (PPP) used for asynchronous communication

  • Connectivity across interconnected networks with different operating systems and hardware platforms, including communication with many non-Microsoft systems, such as Internet hosts, Apple® Macintosh® systems, IBM® mainframes, UNIX® systems, and Open VMS™ systems

  • Support for automatic TCP/IP configuration using Windows NT Dynamic Host Configuration Protocol (DHCP) servers

  • Support for automatic IP-address-to-NetBIOS computer name resolution using Windows NT Windows Internet Naming Service (WINS) servers

  • Support for the Windows Sockets 1.1 interface, which is used by many client-server applications and many public-domain Internet tools

  • Support for the NetBIOS interface, commonly known as NetBIOS over TCP/IP

  • Support for many commonly used utilities, which are installed with the protocol

Microsoft NetBEUI.

This protocol is compatible with existing networks that use NetBIOS extended user interface (NetBEUI), including Windows for Workgroups peer networks, Windows NT Server, LAN Manager, and other networks, and includes support for a NetBIOS programming interface. Windows 95 provides both protected-mode and real-mode support for this protocol.

NetBEUI was first introduced by IBM in 1985, when it was assumed that LANs would be segmented into workgroups of 20 to 200 computers and that gateways would be used to connect one LAN segment to other LAN segments or to a mainframe. NetBEUI is optimized for high performance when used in departmental LANs or LAN segments. Microsoft NetBEUI under Windows 95 is completely self-tuning and provides much better performance over slow links than did earlier versions of NetBEUI.

All three protocols are Plug and Play-compliant, so they can be loaded and unloaded automatically. For example, if a PCMCIA network adapter is removed from the computer so that the network is no longer available, the protocols are unloaded automatically after any dependent applications have been notified.

Network Adapters and Protocols: The Issues

Windows 95 Setup automatically configures a computer to use protocols and drivers to match network components that are running when Setup is started.

If you are setting up Windows 95 for a new networking option, you must choose which types of network adapter drivers and protocols to use. Because Windows 95 has an open architecture, you have a lot of flexibility in this decision. Windows 95 supports both NDIS and Transport Driver Interface (TDI) standards, allowing Windows 95 to communicate with many other networking products and making it possible to choose from a variety of network adapters and protocols.

This section describes basic issues for choosing network adapter drivers and protocols to support your networking needs.

Choosing adapters and drivers for best performance.

Network adapters have become exceptionally reliable and inexpensive. The low cost of Ethernet adapters, including new Plug and Play hardware, means that usually the cost-effective way to improve network performance is to replace an older network adapter with a new model. The cost for the new hardware is offset almost immediately by savings in support time and improved performance. In choosing a new network adapter, you should also consider buying an adapter that matches the computer bus. For example, PCI network adapters are available for use in PCI computers.

Choosing separate protocol and adapter drivers.

With some networks, each computer's network adapter driver and protocol are separate pieces of software. With other networks, a single piece of software called a monolithic protocol stack acts as both adapter driver and protocol. Microsoft recommends that you choose separate 32-bit, protected-mode protocols and drivers rather than monolithic stacks, which run only in real mode. However, Windows 95 includes mapping technology for users who must continue to use real-mode NDIS 2 or ODI drivers.

Choosing NDIS versus ODI drivers.

Windows 95 supports NDIS versions 2.x and 3.1. All network adapter drivers and protocols shipped with Windows 95 conform to NDIS. You can use any combination of protocol and network adapter drivers that conforms to NDIS. Microsoft recommends that you use NDIS 3.1 drivers whenever possible with Windows 95.

The Open Datalink Interface (ODI) specification was defined by Novell and Apple Computer to provide a protocol and API for communicating with network adapter drivers, and to support the use of multiple protocols by a network adapter driver. To ensure the most flexibility in Windows 95, Microsoft recommends that you use NDIS 3.1 drivers whenever possible if you are running Windows 95 with Microsoft Client for NetWare Networks. If you are using a Novell-supplied network client, Novell recommends using ODI-based client software rather than monolithic IPX drivers.

Choosing a protocol.

Windows 95 can support multiple network protocols, and can share a protocol among the network providers that are installed. You might choose more than one protocol to ensure communication compatibility with all systems in the enterprise. However, choosing multiple protocols can cause more network traffic, more memory used on the local workstations, and more network delays. You probably want to choose a single protocol wherever possible. The following briefly presents some issues for each Windows 95 protocol.

For the IPX/SPX-compatible protocol:

  • This protocol is required and installed automatically with Microsoft Client for NetWare. When Windows 95 Setup determines that it cannot install Client for NetWare Networks on a computer running a Novell-supplied network client, Setup still tries to install this protected-mode protocol. For information about how Setup determines whether to install this protocol automatically, see Chapter 9, "Windows 95 on NetWare Networks."

  • This protocol cannot be used to configure Windows 95 to support NetWare over ArcNet. Instead, you must use real-mode IPX drivers with NetBIOS support on ArcNet network adapters.

  • With this protocol, it is not necessary to load the Novell-supplied VIPX.386 driver, because the Microsoft protocol provides virtualized services to all VMs and applications.

For Microsoft TCP/IP:

  • TCP/IP in general has been known to require careful planning and management of the IP address space. However, this problem is vastly reduced when DHCP servers are used to manage assignment of IP addresses for computers running Microsoft TCP/IP.

  • If you want to take advantage of DHCP for automatic IP addressing or use WINS for name resolution on computers running Windows 95, the appropriate Windows NT servers must be in place on the network.

  • This protocol cannot be used on NetWare networks that require NetWare/IP.

For Microsoft NetBEUI:

  • NetBEUI is a nonroutable protocol that cannot cross routers, although it can cross bridges and source routing bridges.

  • NetBEUI is optimized for high performance only for use in departmental LANs or LAN segments.

One common method for setting up a network is to use NetBEUI plus a protocol such as TCP/IP on each computer that needs to access computers across a router. If you set NetBEUI as the default protocol, Windows 95 uses NetBEUI for communication within the LAN segment and uses TCP/IP for communication across routers to other parts of the WAN.

Network Adapters and Windows 95

Windows 95 supports up to four network adapters in a single computer. Windows 95 Setup automatically detects most network adapters, installs the appropriate driver for the adapter, and provides appropriate default settings to configure the adapter. If you add a new network adapter, its driver is bound automatically to all NDIS protocols currently running on the computer; if any protocols are added later, they will also be bound automatically to the network adapter driver.

This section provides technical details for configuring network adapters, setting LAN adapter numbers, and other technical notes. For specific information about PCMCIA adapters, see Chapter 19, "Devices."

Note: For information about specific network adapters, see the SETUP.TXT and README.TXT files in the Windows 95 distribution disks.

Configuring Network Adapters

This section discusses how to configure properties for network adapter drivers.

Important: If you add a new network adapter after Windows 95 is installed, you should use the Add New Hardware option in Control Panel to install the correct driver for the adapter.

When you use the Add New Hardware option, be sure to choose Detection for determining the correct driver and resource assignment. You should configure network adapter drivers manually only after you have tried all detection and automatic configuration methods.

If you experience problems with settings for a network adapter, you should begin troubleshooting by removing the network adapter driver in the Network option in Control Panel. Then use the Add New Hardware option to reinstall support for the network adapter, using detection to ensure that Windows 95 determines the correct adapter driver and standard settings for that network adapter.

To configure properties manually for network adapter drivers

  • In the Network option in Control Panel, click the Configuration tab. Select the driver in the list, and then click Properties.

To specify the driver type for a selected network adapter

  1. In the properties for the network adapter, click the Driver Type tab.

  2. Click one of three options (if available for the specific adapter), as described in the following table.


    Network adapter driver type


    Enhanced mode (32-bit and 16-bit) NDIS driver

    Installs an NDIS 3.1-compliant driver. This is the preferred driver type for use with 32-bit, protected-mode network clients.

    Real-mode NDIS driver

    Installs an NDIS 2.x-compliant driver.

    Real-mode (16-bit) ODI driver

    Installs a real-mode driver created to support ODI for Windows 3.1 on NetWare networks.

Binding Network Adapter Drivers to Protocols

For a protocol to communicate with each network adapter on your computer, the network adapter driver must be bound to the protocol. The bindings define the relationships between networking software components. Windows 95 automatically binds the appropriate protocols to the network adapter.

You can change the bindings, for example, if you do not want to use a specific protocol with a particular network adapter. Or, as another example, if the computer is on a local area network and is also connected to the enterprise internetwork, you might not want the computer's shared resources to be seen on the internetwork. In that case, you can disable the binding between the related protocol and the adapter that connects the computer to the internetwork.

To configure bindings between a network adapter and installed protocols

  1. In the properties for the selected network adapter, click the Bindings tab.

    In the list, the protocols that are bound to the selected adapter are checked. If a particular protocol does not appear in the list, check that it is installed correctly by returning to the Configuration properties dialog box and reinstalling it.

  2. If you do not want this network adapter to be bound to a particular protocol, click the check box beside the protocol to clear the check.

Configuring Network Adapter Resource Settings

Windows 95 can determine hardware settings for most network adapters. For this reason, the recommended method for installing or configuring network adapter drivers is to use the Add New Hardware option in Control Panel, using detection to determine the correct driver and resource settings. You should accept the proposed settings unless you are absolutely sure they are incorrect.

Most devices cannot share IRQ settings, memory buffer addresses, or ROM addresses. Where possible, Windows 95 identifies and resolves conflicts. However, if one of the supported devices does not seem to work, the problem may be the particular hardware configuration. To make sure there are no conflicts among network adapters or other peripherals, or between the system board and adapters, check the settings in Device Manager, as described in Chapter 19, "Devices."

Sometimes settings for network adapters are set with software, sometimes with jumpers or switches on the hardware (refer to your hardware documentation for specific details). If settings for a network adapter can be configured through software, you can configure settings using the Network option in Control Panel.

To configure resources in a network adapter's properties

  1. In the properties for the network adapter, click the Resources tab.

  2. Click the option titled Use These Hardware Settings, and confirm values for the listed settings by comparing the proposed settings with the values recommended in the documentation for the adapter.

    To select from the available values for a setting, click the arrow beside the setting's current value.

    • A hash (#) character appears by current settings.

    • An asterisk (*) appears beside settings that conflict with another device in the system. You should avoid this setting or reconfigure the other devices to use different settings.


The settings available depend on the type of network adapter. For example, for Intel adapters, you cannot set the IRQ using the adapter's properties. The following table describes a few typical settings.

Setting type


I/O Address Range

Specifies the reserved memory address range (as a hexadecimal value) that the adapter can use for temporary storage of I/O data.

Interrupt (IRQ)

Specifies the hardware line over which the device can send interrupts (requests for service) to the computer's CPU.

Memory Address

Specifies the base memory address (as a hexadecimal value) used by this network adapter. This number must match the adapter's memory address settings, as specified in the documentation for the adapter.

Each alternate Configuration Type that might be listed in the Resources properties for a network adapter refers to a possible hardware configuration for the adapter (rather than software settings for the driver) as defined by the manufacturer.

To configure a network adapter that has alternate Configuration Types

  • Run the Add New Hardware option in Control Panel, and let Windows 95 detect the hardware.

    If you must set the configuration manually, use the settings prescribed in the documentation provided by the manufacturer to set Resources and Advanced properties using the Network option in Control Panel.

The following table describes the network adapters that have alternate Configuration Types under Windows 95. For more information about these configurations, see the documentation from the hardware manufacturer.

Network adapter

Alternate Configuration Types

3Com® EtherLink II®-16

Memory Mapped (RAM), Programmed I/O (PIO)

DEC™ Etherworks™ 3

2K (option 0), 32K (option 1), 64K (option 2)


Memory Mapped (RAM), Programmed I/O (PIO)


Can use shared RAM (memory-mapped), but this mode is not supported under Windows 95

Proteon 1390, 1392, 1392+

Memory Mapped (RAM), Programmed I/O (PIO)

For legacy network adapters, the settings that appear in the Resources properties are only some possible settings for the adapter driver, but many adapters have additional settings that can be programmed by running a configuration utility from the adapter manufacturer or by setting jumpers on the adapter itself. Although some of these settings do not appear in the adapter's properties, the resources used could cause conflicts with other system components.

This also means that configuring most legacy network adapters in Windows 95 consists only of specifying the preprogrammed values for the adapter hardware. Changing values for most network adapters by setting properties in Windows 95 does not reprogram the adapter itself. You can verify hardware settings for network adapters only by running the hardware configuration program to view settings, or by checking how the jumpers are set on the adapter itself.

To reprogram adapter settings

  1. Use the configuration disk that came with the adapter to reprogram it.

  2. Write down the settings made so that you can refer to them in the following step.

  3. In the Network option in Control Panel, change the settings to the ones you noted. Then shut down and restart the computer.

For some legacy adapters, it is possible that the adapter uses resources not listed with the Resource properties. For these adapters, the NDIS driver determines the resource settings directly from the adapter itself. Even though these resources do not appear in the list, they can still conflict with other devices. For example, the resource list for the IBM Token Ring adapter shows only the I/O settings, but this adapter also uses IRQ and Memory resources.

Configuring Advanced Properties for Network Adapters

The options available in the Advanced properties vary, depending on the type of network adapter. For information about specific settings that appear for a selected network adapter, see the documentation provided by the manufacturer for the adapter and driver. The manufacturer can also provide guidelines for when to change the default values for advanced configuration options.

To specify advanced settings for the network adapter

  1. In the properties for the selected network adapter, click the Advanced tab.

  2. To change these values, select an item in the Property list, and then select a setting in the Value box.

  3. Click the OK button. Then restart the computer for the changes to take effect.

This example shows the advanced options for an Intel EtherExpress network adapter.


The following examples show some typical settings for general types of network adapters. Network adapters that use the new, fast Ethernet technology might have many more settings. Examples of such adapters include SMC EtherPower 10/100 (9332) PCI Ethernet Adapter, DEC Etherworks 435, and Intel EtherExpress PRO/100. For an explanation of specific settings for a network adapter, see the documentation provided by the adapter manufacturer.

Example setting


For Ethernet adapters:


Transceiver Type
(cable connector)

The transceiver is the device that connects a computer to the network, defined as one of the following values:
• Thick Net, for an AUI or DEC/Intel/Xerox (DIX) connection.
• Thin Net, for a BNC or coaxial (COAX) connection.
• Twisted Pair, for a TPE connection.

For token ring adapters:


I/O Port Base Address

This value specifies the base memory address used by the adapter. To set the I/O address of an IBM 4/16 token ring adapter, select either Primary (A20) or Secondary (A24) for this value. In this case, the driver ignores the I/O settings in the Resource properties.

Network Address

By default, Windows 95 hardware detection uses the address burned into the adapter. To use another network address, type the network address in hexadecimal form, in the format XX-XX-XX-XX-XX-XX; for example, 01-02-03-4E-2D-1F.

Ring Speed

The ring speed is 4 or 16 megabits per second (MBS), and is set by changing a jumper on the adapter or by running the adapter's configuration utility. For example, for an Intel TokenExpress 16/4 adapter, this is set on the adapter itself. The value in Windows 95 should match the physical or software setting.

Setting LAN Adapter Numbers

NetBIOS defines the interface between the network client and the protocol layers using a set of function calls that allow an application to use the protocol services. Because many network applications use NetBIOS to send commands to the protocol driver, the NetBIOS interface is supported by all protocols provided with Windows 95.

Each combination of a NetBIOS network protocol and a network adapter forms a logical network over which computers can communicate with each other. For example, a computer can have a token ring adapter and an Ethernet adapter, and might use NetBEUI on the token ring network and both NetBEUI and TCP/IP on the Ethernet network. In this case, the computer is connected to three logical networks, each of which is assigned a NetBIOS LAN adapter (LANA) number that Windows 95 uses for communication.

When Windows 95 uses multiple protocols, it transmits data first using one protocol, then again using the next protocol, and so on. When multiple protocols are installed on a computer, the first protocol to be used is called the primary protocol.

On a computer running Windows 95, each binding of a protocol to a network adapter has a LAN adapter number assigned to it. (For example, one protocol bound to two network adapters requires two LAN adapter numbers; two protocols each bound to two adapters requires four LAN adapter numbers.)

In Windows 95, LANA numbers are assigned dynamically in sequence of binding order for the protocols, beginning with 7 and then 0, 1, and so on. This accommodates dynamic Plug and Play events such as removing a network adapter while the computer is running. If you are running Windows 95 in such a dynamic environment, Windows 95 cannot guarantee that a given protocol will receive the same LANA number each time the system is started. Although if the computer's network hardware never changes, the LANA numbers may not change at each startup. However, the default protocol is always LANA 0.

You need to change a LAN adapter number only if you have a NetBIOS application that needs to know the LANA number. For example, Lotus Notes® requires that you enter the LANA number that Lotus Notes will use. To configure Windows 95 to use Lotus Notes, set the default protocol to be the NetBIOS-based protocol on which you want to run Lotus Notes. (Setting the default protocol makes it LANA 0.) This protocol can be NetBEUI, IPX/SPX-compatible with NetBIOS support, or TCP/IP.

To select a default protocol for LANA settings

  1. In the Network option in Control Panel, click the Configuration tab.

  2. Double-click the protocol you want to be the default.

  3. In the protocol's properties, click the Advanced tab.

  4. Click the option named Set This Protocol To Be The Default Protocol so that the check box is checked. Then click OK, and shut down and restart the computer for the changes to take effect.

Technical Notes on Network Adapters

This section provides some technical notes for specific network adapters and briefly describes changes to network adapter driver support as compared to Windows for Workgroups 3.11.

NDIS 3.0 network adapter drivers that worked with Windows for Workgroups 3.11 do not work under Windows 95. You must use an NDIS 2.x real-mode driver, an ODI driver, or an updated NDIS 3.1 protected-mode driver for the network adapter. The driver must have a Windows 95 INF file. Many real-mode drivers, updated protected-mode drivers, and supporting INF files are included with Windows 95.

If the network adapter does not appear in the list of adapters in the Network option in Control Panel, you can use information for a Windows 3.x adapter to install it under Windows 95. If you have an OEMSETUP.INF file created for an earlier version of Windows, you can use that INF file by clicking Have Disk in the Select Network Adapter dialog box to install that older network adapter driver.

The major reason that the INF file format has changed for all types of Windows 95 network adapter drivers is that INF files are now used to add information to the Windows 95 Registry. The INF files created for earlier versions of Windows do not contain this kind of information.

IPX/SPX-Compatible Protocol

The Microsoft IPX/SPX-compatible protocol (NWLINK.VXD) supports the 32-bit Windows Sockets programming interface, so that any Win32-based Windows Socket application can run on IPX/SPX with Windows 95. (There are no 16-bit Windows Sockets applications using IPX/SPX.)

The IPX/SPX-compatible protocol can be used by Client for NetWare Networks to communicate with NetWare servers or computers running File and Printer Sharing for NetWare Networks.

This protocol can also be used by Client for Microsoft Networks to communicate with computers running Windows for Workgroups 3.11 or Windows NT that are running the same protocol.

The IPX/SPX-compatible protocol uses the NWNBLINK.VXD module to support computers that use NetBIOS over IPX and to support the NetBIOS programming interface. This protocol can also use NetWare servers configured as routers (and other IPX routers) to transfer packets across LANs.

Configuring IPX/SPX-Compatible Protocol

The Microsoft IPX/SPX-compatible protocol is installed automatically when Client for NetWare Networks is installed. You can also install this protocol to support other network clients, including Client for Microsoft Networks.

When you install the IPX/SPX-compatible protocol, Windows 95 automatically detects and sets appropriate values for the frame type, network address, and other settings. However, in some cases you might need to configure settings for this protocol manually.

To configure the IPX/SPX-compatible protocol

  1. In the Network option in Control Panel, double-click IPX/SPX Compatible Protocol.

    If the computer has multiple network adapters, the list will contain an instance of the IPX/SPX-compatible protocol for each network adapter. You must configure each adapter with its own settings.

  2. Click the Advanced tab.


  3. Most values have correct defaults in typical installations. If you need to change a value for a particular purpose, select the item in the Property list and specify a setting in the Value list based on the information in the following table.



Force even-length IPX packets

Enabled only for Ethernet 802.3 on monolithic implementations that cannot handle odd-length packets.

Frame type1

Specifies the frame type based on detection. This value is used for network adapters that support multiple frame types. The possible values are:
• Auto-detect (recommended)
• Ethernet 802.2 (default for NetWare 3.12 and later)
• Ethernet 802.3
• Ethernet II
• Token ring
• Token ring SNAP

Maximum connections

Specifies the maximum number of connections that IPX will allow. Configured dynamically.

Maximum sockets

Specifies the maximum number of IPX sockets that IPX assigns. Configured dynamically.

Network address

Specifies the IPX network address as a four-byte value. Configured dynamically.

Source routing2

Specifies the cache size to use with source routing. This parameter is used only on token ring networks, where it is used to turn on source routing.
Important Cache size is specified by entry count, not byte count. The recommended value of 16 entries is the most efficient and best setting for most installations.

1 Each time the computer starts, Windows 95 detects the frame type by sending a general RIP request in each frame format. Based on the responses received from routers, Windows 95 determines the most prevalent frame type used and sets that as the default frame type.

2 Source routing is a method of routing data across bridges. For NetWare networks, this means forwarding NetWare frames across an IBM token-ring bridge. With NDIS protocols, source routing is done by the protocol. With ODI-based protocols, source routing is configured with the network adapter driver or using the NetWare ROUTE.COM utility.

You should not need to change bindings in most circumstances. However, you can disable the bindings for a protocol if you do not want other computers using that protocol to see this computer. At least one protocol, however, must be bound to the network client for the computer to communicate with the network.

To change bindings for the IPX/SPX-compatible protocol

  1. In the properties for the IPX/SPX-compatible protocol, click the Bindings tab.

  2. Click any network component to change its bindings.

    If the option is checked, it is bound to the protocol. If it is not checked, that network component is not using the IPX/SPX-compatible protocol. For more information, see "Configuring Network Adapters" earlier in this chapter.

Note: Microsoft Client for NetWare Networks is always bound only to the IPX/SPX-Compatible Protocol. This network client cannot use another protocol.

Using NetBIOS over IPX

NetBIOS is an interface used by network applications to communicate with other NetBIOS-compliant applications. The NetBIOS interface is responsible for the following:

  • Establishing logical names on the network

  • Establishing connections (called sessions) between two computers by use of their logical names on the network

  • Transmitting data between networked computers

Windows 95 provides a 32-bit, protected-mode driver to support NetBIOS services over IPX (VNETBIOS.386). This implementation is compatible with the Novell NetBIOS support driver. Performance enhancements include acknowledgment of previous frames in response frames (called PiggyBackAck), plus a "sliding window" acknowledgment mechanism.

These NetBIOS enhancements are used only when the computer is communicating with other computers using IPX over NetBIOS, such as other computers running Windows 95, Windows NT, or NetWare when running Lotus Notes or other NetBIOS applications. NetBIOS over IPX is not necessary for computers running Windows 95 to be able to communicate with each other. The redirector and server networking components in Windows 95 communicate with the IPX protocol directly without NetBIOS.

Novell provides a TSR NetBIOS driver named NETBIOS.EXE, which is a Level 1 NetBIOS provider that consumes about 40K of conventional memory. This driver acknowledges each frame received, thus increasing the amount of traffic generated when NetBIOS is used. With the Microsoft implementation of NetBIOS over IPX, you can remove the real-mode NETBIOS.EXE TSR.

Note: A computer running Windows 95 that uses IPX without NetBIOS can connect to a Windows NT 3.5 server that uses IPX without NetBIOS. However, the Windows NT 3.5 workstation service (not Windows NT Workstation) can only connect to a computer running File and Printer Sharing for Microsoft Networks when the computer running Windows 95 is using NetBIOS over IPX.

To use the IPX/SPX-compatible protocol with NetBIOS on a computer

  • In the properties for the IPX/SPX-compatible protocol, click the NetBIOS tab, and then click I Want To Enable NetBIOS Over IPX/SPX.

IPX/SPX Technical Notes on NetWare Networks

  • There is no need to enable Source Routing on token ring networks if the communication is on the same ring, even if one computer has it enabled.

  • SPX-II is a protocol definition for windowing and transmitting large packets over SPX. You can run any SPX-II application under Windows 95 using the IPX/SPX-compatible protocol. The related Novell-supplied file TLI.DLL must be available on the computer to support SPX-II.

  • The IPX/SPX-compatible protocol in Windows 95 uses NET.CFG parameters for NetBIOS over IPX on NetWare networks. However, it should not be necessary for you to configure these parameters, because most parameters are dynamic and self-adjusting. (When you install Windows 95 with protected-mode networking components, NET.CFG and SHELL.CFG parameters are moved to the Registry.)

  • To determine the network address in IPX packets, Windows 95 checks the wire for RIP packets and chooses the most likely address. The network address is dynamic and changes when a new network address becomes more prevalent.

  • All Transport Layer Interface (TLI) libraries can run on the IPX/SPX-compatible protocol in Windows 95. TLI is similar to TDI in Microsoft networking as a layer between the protocol and network adapter driver; this implementation is similar to STREAMS and provides a STREAMS environment for NetWare, but Windows 95 uses Windows Sockets instead.

TCP/IP Protocol

Microsoft TCP/IP provides communication across interconnected networks that use diverse hardware architectures and various operating systems. TCP/IP can be used to communicate with computers running Windows 95, with devices using other Microsoft networking products, or with non-Microsoft systems such as UNIX.

Microsoft TCP/IP provides all the following elements necessary for networking:

  • Core TCP/IP protocols, including the Transmission Control Protocol (TCP), Internet Protocol (IP), User Datagram Protocol (UDP), Address Resolution Protocol (ARP), Internet Control Message Protocol (ICMP), and Domain Name Protocol (DNS). This suite of Internet protocols provides a set of standards for how computers communicate and how networks are interconnected.

  • Support for application programming interfaces, including Windows Sockets and NetBIOS.

  • TCP/IP diagnostic tools to detect and resolve TCP/IP networking problems, including arp, ftp, nbtstat, netstat, ping, route, and tracert, plus Windows-based Telnet and IP Configuration (WINIPCFG) utilities.

In addition, when you install Microsoft TCP/IP under Windows 95, the following enhancements are included:

  • Client for DHCP, for automatic configuration of computers running TCP/IP on networks that have DHCP servers

  • Client for WINS, for dynamic resolution of IP addresses to computer names on networks that have WINS servers

  • Point-to-Point Protocol for asynchronous communication, as described in Chapter 28, "Dial-Up Networking and Mobile Computing"

For a summary of the command-line options for TCP/IP utilities, see Appendix A, "Command-Line Commands Summary."

Configuring TCP/IP with DHCP

In an effort to make implementing the TCP/IP protocol more manageable, Microsoft worked with other industry leaders to create an Internet standard called Dynamic Host Configuration Protocol (DHCP) for the automatic allocation of IP addresses. DHCP is not a Microsoft standard, but a public Request for Comments (RFC 1541) that Microsoft has implemented.

DHCP allows you to establish a range of valid IP addresses to be used per subnetwork. An individual IP address from the range is assigned dynamically to any DHCP client requesting an address. DHCP also allows you to establish a lease time that defines how long an IP address is to remain valid. Other configuration parameters can also be assigned using DHCP, such as subnet mask, DNS and WINS server identification, and so on.

A computer running Windows 95 cannot be a DHCP server. A DHCP server runs as a service on a Windows NT 3.5 Server computer. If DHCP is available company-wide, users can move from subnet to subnet and always have a valid IP address. The IP Configuration utility (WINIPCFG) allows users or administrators to examine the current IP address assigned to the computer, the IP address lease time, and other useful data about the TCP/IP configuration.

When TCP/IP is installed, Windows 95 automatically enables the option to obtain an IP address from a DHCP server. This option can be disabled using the Network option in Control Panel if you want to enter an IP address manually.

If Microsoft TCP/IP is configured to obtain an IP address from a DHCP server when a DHCP server is not available on the network, the next time Windows 95 starts, an error message announces that the DHCP client could not obtain an IP address. To solve this problem, use the procedure described in the following section to configure TCP/IP manually.

Configuring TCP/IP Settings Manually

If you cannot use DHCP for automatic configuration, the network administrator must provide values so that individual users can configure TCP/IP manually. Or, if custom setup scripts are used to install Windows 95, the correct values can be defined in the setup script. The required values include the following:

  • The IP address and subnet mask for each network adapter installed on the computer.

  • The IP address for the default gateways (IP routers).

  • Whether the computer will use Domain Name System (DNS) and, if so, the IP addresses of the DNS servers on the internetwork.

  • WINS server addresses, if WINS servers are available on the network.

The following procedure describes the basic configuration options for TCP/IP. If you want to configure the computer to use WINS or DNS for name resolution, see the procedures in "Using WINS for Name Resolution" later in this chapter and "Using DNS for Name Resolution" later in this chapter.

To configure the TCP/IP protocol manually

  1. In the Network option in Control Panel, double-click Microsoft TCP/IP in the list of installed components.

    Note: If your computer has multiple network adapters, the list includes an instance of TCP/IP for each network adapter. You must configure each adapter with its own IP address, subnet mask, and gateway. All other settings apply system-wide.

  2. In Microsoft TCP/IP properties, click the IP Address tab.


  3. Click the option named Specify An IP Address.

  4. Type an IP address and subnet mask in the respective boxes.

    The network administrator must provide these values for individual users, based on the network ID and the host ID plan for your site.

    • The value in the IP Address box identifies the IP address for the local computer or, if more than one network adapter is installed, for the network adapter selected in the Configuration dialog box.

    • The value in the Subnet Mask box identifies the network membership and its host ID for the selected network adapter. The subnet mask defaults to an appropriate value, as shown in the following list.

      Address class

      Range of first octet in the IP address

      Subnet mask

      Class A


      Class B


      Class C


    To view or specify which network clients are bound to the TCP/IP protocol, click the Bindings tab.

    • To keep a network client from using the TCP/IP protocol, make sure the checkmark beside the client name is cleared.

    • If the network client for which you want to use TCP/IP does not appear in this list, that client might not be installed properly. Return to the Configuration dialog box and reinstall that network client.

    Note: The only network client provided with Windows 95 that can use Microsoft TCP/IP is Client for Microsoft Networks. Client for NetWare Networks does not use Microsoft TCP/IP.

    NetWare/IP from Novell allows the NCP request to be sent over an IP header. You can use NetWare/IP only with a Novell-provided, real-mode client.

  5. Click the Gateway tab. Type at least one IP address for the default gateway (IP router) on the network, and then click Add.


  6. To specify an IP address for an additional gateway, type the IP address in the New Gateway box, and then click the Add button.

    The first gateway in the list is the default gateway. Gateway addresses can be prioritized by dragging the IP address in the list of installed gateways. Windows 95 attempts to connect to other gateways only if the primary gateway is unavailable.

  7. Click OK, and then restart the computer for changes to take effect.

If you are using Dial-Up Networking to connect to the Internet, you can manually configure DNS and IP addresses for each connection that you define. For more information about defining IP addresses for each connection and about IP addresses on TCP/IP networks, see Chapter 30, "Internet Access." For more information about TCP/IP Registry entries, see Chapter 30, "Internet Access."

Name Resolution for Windows Networking

For TCP/IP and the Internet, the globally known system name is the computer's host name, appended with a DNS domain name (for example, This defaults to the computer name (NetBIOS name) defined during Windows 95 Setup. The default name can be changed in the DNS dialog box when you are configuring TCP/IP properties.

Computers use IP addresses to identify each other, but users usually find it easier to work with computer names. A mechanism must be available on a TCP/IP network to resolve names to IP addresses. To ensure that both the name and the address are unique, the computer using Microsoft TCP/IP registers its name and IP address on the network during system startup. Computers running Microsoft TCP/IP on the network can use one or more methods for name resolution in TCP/IP internetworks, as summarized in this section.

Broadcast name resolution.

Computers running Microsoft TCP/IP can use broadcast name resolution, which is a NetBIOS-over-TCP/IP mode of operation defined in RFC 1001/1002 as b-node. This method relies on a computer making IP-level broadcasts to register its name by announcing it on the network. Each computer in the broadcast area is responsible for challenging attempts to register a duplicate name and for responding to name queries for its registered name.


An LMHOSTS file specifies the NetBIOS computer name and IP address mappings; a HOSTS file specifies the DNS name and IP address. On a local computer, the HOSTS file (used by Windows Sockets applications to find TCP/IP host names) and LMHOSTS file (used by NetBIOS over TCP/IP to find NetBIOS computer names) can be used to list known IP addresses mapped with corresponding computer names. LMHOSTS is used for name resolution in Windows 95 for internetworks where WINS is not available.

  • The HOSTS file is used as a local DNS equivalent to resolve host names to IP addresses.

  • The LMHOSTS file is used as a local WINS equivalent to resolve NetBIOS computer names to IP addresses.

Each of these files is also known as a host table. Sample versions of LMHOSTS (called LMHOSTS.SAM) and HOSTS files are added to the Windows directory when you install Windows 95 with TCP/IP support. These files can be edited using any ASCII editor, such as WordPad or Edit. To take advantage of HOSTS or LMHOSTS, DNS must be enabled on the computer. For information about setting up and using HOSTS and LMHOSTS files, see Appendix G, "HOSTS and LMHOSTS Files for Windows 95."

Windows Internet Name Service.

Computers running Microsoft TCP/IP can use WINS if one or more Windows NT Server computers configured as WINS servers are available, containing a dynamic database for mapping computer names to IP addresses. WINS can be used in conjunction with broadcast name resolution for an internetwork, where other name resolution methods are inadequate. WINS is a NetBIOS-over-TCP/IP mode of operation defined in RFC 1001/1002 as h-node or m-node; WINS clients default to h-node. Notice that WINS is a dynamic replacement for the LMHOSTS file. For more information, see "Using WINS for Name Resolution" later in this chapter.

Domain Name System name resolution.

DNS provides a way to look up name mappings when connecting a computer to foreign hosts using NetBIOS over TCP/IP or Windows Sockets applications such as FTP. DNS is a distributed database designed to relieve the traffic problems that arose with the first growth explosion on the Internet in the early 1980s. A DNS name server must be configured and available on the network. Notice that DNS replaces the functionality of the HOSTS file by providing a dynamic mapping of IP addresses to host names used by TCP/IP applications and utilities. For more information, see "Using DNS for Name Resolution" later in this chapter.

Windows 95 provides support for multiple DNS servers and up to two WINS servers. Support for either service can be configured automatically from a DHCP server, manually in Windows 95 Setup, or after Setup by using the Network option in Control Panel.

Using WINS for Name Resolution

WINS provides a distributed database for registering and querying dynamic computer name-to-IP address mappings in a routed network environment. If you are administering a routed network that includes computers running Windows NT Server, WINS is your best choice for name resolution, because it is designed to solve the problems that occur with name resolution in more complex internetworks.

WINS reduces the use of local broadcasts for name resolution and allows users to locate computers on remote networks automatically. Furthermore, when dynamic addressing through DHCP results in new IP addresses for computers that move between subnetworks, the changes are updated automatically in the WINS database. Neither the user nor the network administrator needs to make manual accommodations for name resolution in such a case.

The WINS protocol is based on and is compatible with the protocol defined for WINS server in Requests for Comments (RFCs) 1001 and 1002, so it is interoperable with any other implementations of these RFCs. WINS consists of two components: the WINS server, which handles name queries and registrations, and the client software (NetBIOS over TCP/IP), which queries for computer name resolution. A WINS server is a Windows NT Server 3.5 computer with WINS server software installed. When Microsoft TCP/IP is installed under Windows 95, WINS client software is installed automatically.

Windows networking clients that are WINS-enabled can use WINS directly. Non-WINS computers on the internetwork that are b-node – compatible, as described in RFCs 1001 and 1002, can access WINS through proxies, which are WINS-enabled computers that listen to name query broadcasts and then respond for names that are not on the local subnet or are h-nodes.

On a Windows network, users can browse transparently across routers. To allow browsing without WINS, you must ensure that the users' primary domain has Windows NT Server computers on both sides of the router to act as master browsers. These computers need to contain correctly configured LMHOSTS files with entries for the domain controllers across the subnet.

With WINS, such strategies are not necessary, because the WINS servers and proxies provide the support necessary for browsing Windows NT domains across routers. For a technical discussion of how WINS works and how it can be set up on the network, see Windows NT Server 3.5 TCP/IP in the Windows NT Server 3.5 documentation set.

If there are WINS servers installed on your network, you can use WINS in combination with broadcast name queries to resolve NetBIOS computer names to IP addresses. If you do not use this option, Windows 95 can use name query broadcasts (b-node mode of NetBIOS over TCP/IP) plus the local LMHOSTS file to resolve computer names to IP addresses. Broadcast resolution is limited to the local network, as described earlier in this section.

If DHCP is used for automatic configuration, these parameters can be provided by the DHCP server. Otherwise, you must configure information about WINS servers manually. WINS configuration is global for all network adapters on a computer.


To configure a computer to use WINS for name resolution

  1. In the Microsoft TCP/IP properties, click the WINS Configuration tab.

  2. If a DHCP server is available that is configured to provide information on available WINS servers, select Use DHCP For WINS Resolution.

    – Or –

    If a WINS server is available but not a DHCP server, select Enable WINS Resolution and type the IP addresses of the Primary and Secondary WINS servers. These values should be provided by the network administrator, based on the IP addresses assigned to these Windows NT Server computers.

  3. If WINS is enabled, in the Scope ID box, type the computer's scope identifier, if required on an internetwork that uses NetBIOS over TCP/IP.

    Usually this value is left blank. Scope IDs are used only for communication based on NetBIOS over TCP/IP. In such a case, all computers on a TCP/IP internetwork must have the same scope ID. A scope ID can be assigned to a group of computers if those computers communicate only with each other and not with computers outside the group. Such computers can find each other if their scope IDs are identical.

Using DNS for Name Resolution

DNS provides a distributed database that contains a hierarchical naming system for identifying hosts on the Internet. The specifications for DNS are defined in Requests for Comments (RFCs) 1034 and 1035.

Although DNS may seem similar to WINS, there is one major difference: DNS requires static configuration of IP addresses for name-to-address mapping. WINS can provide name-to-address mapping dynamically and requires far less administration.

The DNS database is a tree structure called the domain name space, where each node or domain is named and can contain subdomains. The domain name identifies the domain's position in the database in relation to its parent domain, with a period (.) separating each part of the name for the network nodes of the DNS domain.

The root of the DNS database is managed by the Internet Network Information Center. The top-level domains were assigned organizationally and by country. These domain names follow the International Standard 3166. Two-letter and three-letter abbreviations are used for countries, and various abbreviations are reserved for use by organizations, as shown in the following example.

DNS domain name

Type of organization


Commercial (for example,


Educational (for example, for Massachusetts Institute of Technology)


Government (for example, for the National Science Foundation)


Noncommercial organizations (for example, for FidoNet)


Networking organizations (for example, for NSFNET)

DNS uses a client-server model, where the DNS servers contain information about a portion of the DNS database and make this information available to clients, called resolvers, that query the name server across the network. DNS name servers are programs that store information about parts of the domain name space called zones. The administrator for a domain sets up name servers that contain the database files with all the resource records describing all hosts in their zones. DNS resolvers are clients that are trying to use name servers to gain information about the domain name space.

All the resolver software necessary for using DNS on the Internet is installed with Microsoft TCP/IP.

Microsoft TCP/IP includes the DNS resolver functionality used by NetBIOS over TCP/IP and Windows Sockets connectivity applications such as FTP and Telnet to query the name server and interpret the responses.

The key task for DNS is to present friendly names for users and then resolve those names to IP addresses, as required by the internetwork. If a local name server doesn't contain the data requested in a query, it sends back names and addresses of other name servers that could contain the information. The resolver then queries the other name servers until it finds the specific name and address it needs. This process is made faster because name servers continuously cache the information learned about the domain name space as the result of queries.

Although TCP/IP uses IP addresses to identify and reach computers, users typically prefer to use host names. DNS is a naming service generally used in the UNIX networking community to provide standard naming conventions for IP workstations. TCP/IP utilities, such as FTP and Telnet, can also use DNS in addition to the HOSTS file to find computerws, when connecting to foreign hosts or computers on your network.

You need to determine whether users should configure their computers to use DNS. Usually you will use DNS if you are using TCP/IP to communicate over the Internet or if your private internetwork uses DNS to distribute host information.

Microsoft TCP/IP provides a DNS client for resolving Internet or UNIX system names. Windows networking provides dynamic name resolution for NetBIOS computer names using WINS servers and NetBIOS over TCP/IP, as described in the previous section.

If you choose to use DNS, you must configure how the computer will use DNS and the HOSTS file. DNS configuration is global for all network adapters installed on a computer. If DHCP is used for automatic configuration, these parameters can be provided by the DHCP server.


To configure a computer to use DNS for name resolution

  1. In the Microsoft TCP/IP properties, click the DNS Configuration tab.

  2. If a DNS server is available, click Enable DNS. Then specify a host name and complete the other configuration information as described in the following procedure.

Tip You must enable DNS on each computer that needs to use LMHOSTS for name resolution.

The host name is used to identify the local computer for authentication by some utilities. Other TCP/IP-based utilities can use this value to learn the name of the local computer. Host names are stored on DNS servers in a table that maps names to IP addresses for use by DNS.

To set the host name for DNS

  • Type a name in the Host Name box.

    The name can be any combination of the letters A through Z, the numerals 0 through 9, and the hyphen (-), plus the period (.) character used as a separator. By default, this value is the Microsoft networking computer name, but the network administrator can assign another host name without affecting the computer name.

Note: Some characters that can be used in computer names, especially the underscore, cannot be used in host names.

The TCP Domain Name is used with the host name to create a fully qualified domain name (FQDN) for the computer. The FQDN is the host name followed by a period (.), followed by the domain name. For example, this could be, where johndoe is the host name and is the domain name.

During DNS queries, the local domain name is appended to short names. A short name consists of only a host name, such as janedoe. When querying the DNS server for the IP address of janedoe, the domain name is appended to the short name, and the DNS server is actually asked to resolve the FQDN of Notice that the FQDN of Jane Doe at Microsoft ( is not the same as her Internet electronic mail address of

To set the DNS domain name

  • Optionally, type a name in the Domain Name box.

    This is usually an organization name followed by a period and an extension that indicates the type of organization, such as The name can be any combination of the letters A through Z, the numerals 0 through 9, and the hyphen (-), plus the period (.) character used as a separator.

Note: A DNS domain is not the same as a Windows NT or LAN Manager domain. A DNS domain is a hierarchical structure for organizing TCP/IP hosts and provides a naming scheme used in UNIX environments. A Windows NT or LAN Manager domain is a grouping of computers for security and administrative purposes.

You can add up to three IP addresses for DNS servers. For a given DNS query, Windows 95 attempts to get DNS information from the first IP address in the list. If no response is received, Windows 95 goes to the second server in the list, and so on. To change the order of the IP addresses, you must remove them and retype them in the order that you want the servers to be searched.

To set the DNS server search order

  1. In the Domain Name System (DNS) Search Order box, type the IP address of a DNS server that will provide name resolution. Then click the Add button to add the IP address to the list.

    The network administrator should provide the correct values for this parameter, based on the IP address assigned to the DNS server used at your site.

  2. To remove an IP address from the list, select it, and then click the Remove button.

Note: If you have two servers listed in this dialog box, Windows 95 checks the second server only if no response is received from the first server. If Windows 95 attempts to check a host name with the first server and receives a message that the host name is not recognized, the system does not try the second DNS server.

The Domain Suffix Search Order specifies the DNS domain suffixes to be appended to host names during name resolution. You can add up to five domain suffixes. Domain suffixes are placed in the list in alphabetic order.

To set the domain suffix search order

  1. In the Domain Suffix Search Order box, type the domain suffixes to add to your domain suffix search list, and then click the Add button.

  2. To remove a domain name from the list, select it, and then click the Remove button.

When attempting to resolve a fully qualified domain name (FQDN) from a short name, Windows 95 will first append the local domain name. If this is not successful, Windows 95 will use the Domain Suffix list to create additional FQDNs and query DNS servers in the order listed.

Microsoft NetBEUI Protocol

Windows 95 provides the NetBIOS extended user interface (NetBEUI) protocol for compatibility with existing networks that use NetBEUI. Because NetBEUI is nonroutable and was designed for smaller LANs, you should use the TCP/IP or IPX/SPX-compatible protocol for enterprise-wide networks that require a routable protocol.

NetBEUI in Windows 95 supports a NetBIOS programming interface that conforms to the IBM NetBEUI specifications and includes several performance enhancements. The NetBEUI module, NETBEUI.VXD, is accessible through the NetBIOS interface.

If Windows 95 Setup detects NetBEUI during installation, it installs support for Microsoft NetBEUI automatically. You can add or configure this protocol at any time.

To configure NetBEUI manually

  1. In the Network option in Control Panel, click the Configuration tab. Then double-click Microsoft NetBEUI.

    If your computer has multiple network adapters, an instance of NetBEUI appears for each network adapter. You must configure each adapter with its own settings.

    The Bindings tab shows which clients and services are currently using the NetBEUI protocol. For information about configuring bindings, see "Configuring Network Adapters" earlier in this chapter.

  2. Click the Advanced tab to modify settings for Maximum Sessions and NCBs for the real-mode NetBEUI. (The real-mode network runs, for example, when you use Safe Mode for system startup.) Protected-mode NetBEUI dynamically sets Maximum Sessions and NCBs, and therefore does not use these settings.



    Maximum Sessions

    Used to identify the maximum number of connections to remote computers that can be supported from the redirector. This is equivalent to the sessions= parameter formerly specified in PROTOCOL.INI.

    NCBS (network control blocks)

    Used to identify the maximum number of NetBIOS commands that can be used. This is equivalent to the ncbs= parameter formerly specified in PROTOCOL.INI.

  3. Click OK. Then shut down and restart the computer.

Using WinPopup to Broadcast a Pop-Up Message

You can use WinPopup to send a message to one person or to a whole workgroup. WinPopup can also display a message from someone else on your network or from a printer when your print job is done. With WinPopup, you can send and receive messages and alerts from LAN Manager, Windows for Workgroups, Windows NT, and Windows 95 servers and clients.

On a NetWare network, you can also use WinPopup to send messages in the following cases:

  • If you are running a NetWare-compatible client, you can receive pop-up messages from the server you are attached to. You can also receive messages from other users running Novell-supplied network clients if the message is sent to you on the server using NetWare utilities.

  • You can use WinPopup to send a message to a user on a computer running Client for NetWare Networks or a Novell-supplied client if that user is attached to your preferred server.

  • If you are running both Client for NetWare Networks and Client for Microsoft Networks, and if the message reaches the specified computer or user through Windows 95 networking, the message is not also sent through the NetWare server.

WinPopup is installed automatically with either Microsoft for NetWare Network or Client for Microsoft Networks.

To configure WinPopup on a client computer

  1. Place WINPOPUP.EXE in the Startup folder on each computer that you want to receive messages.

  2. On each computer, click the Messages Menu, and then click Options to specify choices for how WinPopup will present messages.


To send a message using WinPopup

  1. Click the Send button on the toolbar. Or, from the Messages menu, click Send.

  2. Click an option to specify whether to send the message to a specific user or computer or to a workgroup. Then type the name for where the message is to be sent.

  3. Type a message, and then click OK.


As an example of how this might be used in a workgroup, you might want to run WinPopup on a computer running File and Printer Sharing services. Every computer in the workgroup that uses shared resources on this computer can also run WinPopup. On each client computer, WinPopup can report messages from the printer (such as notification that a print job has been completed). Or administrators can send messages to users and computers in the workgroup with pop-up notification.

To remove WinPopup from a computer, use the Add/Remove Programs option in Control Panel.

Troubleshooting Protocol Problems

This section contains information about troubleshooting problems related to network protocols. For general information about troubleshooting the network installation, including how to use net diag, see Chapter 7, "Introduction to Windows 95 Networking." For information about troubleshooting procedures and tools provided with Windows 95, see Chapter 35, "General Troubleshooting."

You cannot connect using NetBEUI.

  • Use net diag to test for NetBIOS connectivity over the LANA that NetBEUI is using. If it fails, check the transceiver type, cabling, and adapter.

  • Check the NetBEUI protocol bindings.

  • Verify that routing is not involved.

A NetBIOS application fails to start.

This might be because the application is hard-coded to use the protocol on LANA 0 (such as Lotus Notes). You can force a particular protocol to always occupy LANA 0 by selecting it as the default protocol, as described in "Setting LAN Adapter Numbers" earlier in this chapter.

You cannot connect using the IPX/SPX-compatible protocol.

Verify that both computers trying to connect are using the same frame type and that other settings are correct for this protocol.

  • Verify the following in the Advanced properties for this protocol, as described in "Configuring IPX/SPX-Compatible Protocol" earlier in this chapter:

    • The correct Frame Type is set. The recommended setting is Auto, but this frame type only checks SAP broadcast traffic on the network and might be selecting an incorrect frame type in a mixed frame-type environment.

    • Source Routing is enabled and a cache size is set if needed.

    • The option named Force Even Length Packets is set properly. NetWare servers with older NetWare Ethernet drivers or older IPX routers may require even-sized packets. If required, change this setting to make sure the computer transmits only even-length IPX frames.

  • On the IPX routers, check the setting for Type 20 Packets (NetBIOS packets). When using NetBIOS over IPX, the IPX packet type is set to 14h (decimal 20). Manufacturers of routers might consider all NetBIOS traffic as being nonroutable LAN traffic even when carried over the routable IPX protocol, and so, by default, will not pass Type 20 NetBIOS IPX packets. To use NetBIOS over IPX connectivity, Type 20 packet passing must be enabled on the router.

  • Use net diag to test for IPX connectivity over the related LANA number used by NetBIOS over IPX.

  • Use System Monitor to view statistics for the IPX/SPX-compatible protocol. Then retry network operation and check the activity. If there is none, remove and reinstall the protocol, and then retry and retest the operation.

You cannot connect using TCP/IP.

Use the TCP/IP diagnostic utilities included with Microsoft TCP/IP to isolate network hardware problems and incompatible configurations. The following list describes which utility helps to identify various problems.

Use this utility

To accomplish this action


Check host name, host IP address, and TCP/IP configuration; verify physical connection and remote TCP/IP computer


Detect invalid entries in the ARP table on the local computer


Check the state of NetBIOS over TCP/IP connections, update LMHOSTS cache, and determine registered name and scope ID


Display statistics and state of current TCP/IP connections


Check the route to a remote computer

You can also use the IP Configuration utility (WINIPCFG) to display, update, or release TCP/IP configuration values.

To test TCP/IP using ping

  • Check the loopback address by typing ping and pressing ENTER at the command prompt. The computer should respond immediately. (If you are using DHCP, use the IP Configuration utility to find the IP address.) To determine whether you configured IP properly, use ping with the IP address of your computer, your default gateway, and a remote host.

If you cannot use ping successfully at any point, verify the following:

  • The computer was restarted after TCP/IP was installed and configured.

  • The local computer's IP address is valid and appears correctly in the TCP/IP Properties dialog box.

  • The IP address of the default gateway and remote host are correct.

  • IP routing is enabled on the router, and the link between routers is operational.

  • The local computer's Registry includes an entry for lmhosts=c:\directory that correctly indicates the location of LMHOSTS.

If you can use ping to connect to other computers running Windows 95 on a different subnetwork but cannot connect using Windows Explorer or net use \\server\share, verify the following:

  • The correct host computer name was used.

  • The target host uses NetBIOS. If not, you must use FTP or Telnet to make a connection, and the target host must be configured with the FTP server daemon or Telnet daemon, and you must have correct permissions on the target host.

  • The scope ID on the target host is the same as the local computer.

  • A router path exists between your computer and the target computer.

  • LMHOSTS contains correct entries, so the computer name can be resolved.

  • The computer is configured to use WINS, the WINS server addresses are correct, and WINS servers are functioning.

The "Unable to connect to a server" message appears.

This message appears if name resolution fails for a particular computer name. If the computer is on the local subnetwork, confirm that the target server name is spelled correctly and that the target server is running TCP/IP. If the computer is not on the local subnetwork, be sure that its name and IP address mapping are available in the LMHOSTS file or the WINS database. If all TCP/IP elements appear to be installed properly, use ping with the remote computer to be sure that its TCP/IP software is working.

Use the nbtstat -n command to determine what name (or names) the server registered on the network. The nbtstat command can also display the cached entries for remote computers from either #PRE entries in LMHOSTS or recently resolved names. If the remote computers are using the same name for the server, and the other computers are on a remote subnetwork, be sure that they have the computer's mapping in their LMHOSTS files.

IP address connects but host names do not.

Verify that the HOSTS file and DNS settings have been configured for the computer by checking settings on the DNS Configuration tab.

  • If you are using a HOSTS file, verify that the DNS host name of the remote computer is identical — especially in terms of spelling and capitalization — to the name in the file and the application using it.

  • If you are using DNS, verify that the IP addresses of the DNS servers are correct and in proper order. Use ping with the remote computer, and type both the host name and IP address to determine if the host name is resolved properly.

Use the netstat -a command to show the status of all activity on TCP and UDP ports on the local computer. A good TCP connection is usually established with 0 bytes in the send and receive queues. If data is blocked in either queue or if the state is irregular, there might be a problem with the connection. If not, you are probably experiencing network or application delays.

Connect times are long after adding to LMHOSTS.

You might experience long connect times with a large LMHOSTS file if there is an entry at the end of the file. If so, mark the entry in LMHOSTS as a preloaded entry by following the mapping with the #PRE tag, or place the mapping higher in the LMHOSTS file. Then use the nbtstat -R command to update the local name cache immediately. The LMHOSTS file is parsed sequentially to locate entries without the #PRE keyword. You should place frequently used entries near the top of the file, and place the #PRE entries near the bottom.