Multiple Network Adapters

by Johannes Helmig [Published on 1 July 2000 / Last Updated on 1 July 2000]

This page covers both Windows95 and Windows NT4.

Networking with Windows95 and WindowsNT4 is usually an easy job: Install the "Network Adapter", add "Protocol" and "Client" and you are "talking" over the network. The possibility to define MULTIPLE protocols for a Network adapter (which is so easy to setup due to Microsoft's NDIS support) is highly appreciated by everyone, who tried to setup/configure multiple protocols on a DOS based systems or Windows 3.x-system: It was often impossible! The same is true for installing MULTIPLE Network Adapters: A very difficult (often impossible) task under DOS and Windows 3.x, also a simple job under Windows 95 and Windows NT4.The biggest challenge: IRQ-Resources Since the days of the IBM AT systems, the design of the systems has changed dramatically:

IMB AT Modern Pentium II
Screen resolution:
Floppy disk:
available IRQ's:
6 Mhz
typical 1 MByte
20 MByte
1.44 MByte
300 Mhz
UVGA (1280x1024 / 1600x1200)
typical 16/32/64 MByte
4 GByte
1.44 MByte (plus CD-ROM)
16 !

In today's high-performance systems, we are still stuck with the limit of maximum 16 IRQ-lines ("What is an Interrupt ?"), which is turning into a serious problem on today's Multi-Media Systems with Sound-Boards and SCSI-controllers, in some cases no IRQ is anymore available forcing to switch OFF something else (usually the second Serial-Port COM2, which is not used so often).


Check in the Control-Panel "System", tab: "Device Manager" the "Computer"-properties to locate an unused IRQ. In my example, I did already install the second Network adapter. But if this system had a Sound-board (which usually takes 2 IRQ's) and a SCSI-adapter, no more IRQ would be available.

Windows NT4:

On Windows NT, check the "NT Diagnostics", Tab:"Resources".

When installing a new network-board under Windows95, it will automatically create a binding of ALL currently installed protocols to the new board:

This screen dump is a "fake", because I had to make 2 screenshots to get the full info displayed. All protocols have a Binding to all Network cards. We should clean this up, keeping only the required bindings.

When going to Multi-Network-Adapter/Multi-Protocol setups, it is best to draw it up to get an overview on the goal to be achieved:

In this example, I like to connect on different network cables: - connect to a Novell-Netware server via IPX protocol - connect to a Windows NT system via NetBEUI-protocol - connect to the Internet using the Modem/Dialup-Adapter via TCP/IP. (In my example, I use 2 different network-boards, but it is also possible to install 2 identical network-boards, as long as they are configured for different IRQ and Port-address. To avoid another mis-understanding: if both the Novell-server AND the NT-system are on the SAME network cable, you can connect to them using ONLY ONE Network-adapter and BINDING multiple protocols to this one Network adapter. Please look to this as an exercise)


see below for Windows NT4)

to delete a Binding, select the combination of Protocol->Network board and "Remove" it.

The "cleaned-out" version on the "Network", containing now only the required Bindings. We can now also verify the Bindings by checking the properties of the components:

IPX has a Binding to the 3COM for the connection to the Netware Server.

NetBEUI has a Binding to the NE2000 for the connection to the NT system.

The IPX-protocol has a Binding to the Client for Netware Networks. (I manually un-checked the binding to the Client for Microsoft Network)

The NetBEUI-protocol has a Binding to the Client for Microsoft Networks.

Lets now connect to these systems:

The Netware server does show up in the "Network Neighborhood", but (it is part of the Microsoft mystery of the "Browse-Master") the NT system did NOT show up in the "Network-Neighborhood", but I am able to connect to it by running the "Run"-command: \\<server-name>, in my example: \\piijh.


Lets check the "Network" applet in the Control-Panel.

Since we like to connect to a Novell-netware server, we need in addition to the "Server" and "Workstation" (required to connect to the NT-system) the "Client Services for Netware".

We have the protocols: - NetBEUI to communicate with the NT-system - IPX to communicate to the Novell Netware server

the 2 Network Adapters

The Bindings: Here we need to do the job. First, open (=expand the display) by clicking on the "+" signs.

Then, select and "Disable" all not required Bindings. In this example: no need for the IPX-protocol to have a Binding to the Server and Workstation, which is used for connection to the NT-system.

Then, we are ready to connect and browse the network:

Don't ask me why: But under Windows NT4, both the Novell-server(s) AND the NT-system (PIIJH) are showing up in the "Network-Neighborhood" (each time, when NT is able to do a job not possible/available on Windows95, I say to myself:" Do NOT forget, that Windows95 is only the little brother of the big-boy NT ! ").

See Also

The Author — Johannes Helmig

Dr.Johannes Helmig is working as Director, Technical Knowledge Management in the Belgium office of Gerber Technology where he is involved in Customer Service and internal training, with special interest in Networking.


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