How to Configure WLBS Using Multiple Network Interface Cards (197991)


The information in this article applies to:

  • Microsoft Windows NT Server 4.0
  • Microsoft Windows NT Server, Enterprise Edition 4.0
  • Microsoft Windows NT Load Balancing Service
This article was previously published under Q197991

SUMMARY

The purpose of this article is to describe how to configure Windows NT Load Balancing Service (WLBS) when using multiple network interface cards (NICs).

MORE INFORMATION

The use of a second NIC may improve performance by handling traffic simultaneously with the original NIC. Multicast support is enabled by default. However, if you disable multicast support, the use of multiple network interface cards (with one NIC dedicated to handling cluster traffic) is greatly preferred to achieve optimum performance and the full range of networking functionality.

To set the WLBS bindings for use with multiple network interface cards:

  1. In Control Panel, double-click Network and then click the Bindings tab.
  2. In the Show Binding For drop down list, select All Protocols.

    The bindings for all installed networking protocols can be displayed and modified in this dialog box. Note that WLBS Driver appears in the list of protocols. For each protocol, you can see the network interface cards, also known as adapters, to which each protocol is bound.
  3. Click the plus sign (+) to the left of each protocol to see the adapters to which it is bound. When the bindings are displayed, you will see a minus sign (-) to the left of the protocol.

    You will notice that WLBS Virtual NIC appears in the list of adapters for the TCP/IP and WINS Client protocols. WLBS registers itself with Windows NT as both a protocol and as a virtual network adapter. In addition, you should see at least two other adapters corresponding to actual NICs installed in your system.
To set the proper bindings:

  1. Enable the binding from the WLBS Driver to the WLBS Virtual NIC adapter. To enable a binding, select the adapter and click Enable.
  2. Enable the binding from the WLBS Driver to the network adapter that will handle cluster traffic (called the cluster adapter).
  3. Disable the binding from the WLBS Driver to all other adapters. To disable a binding, select the adapter and click Disable.
  4. Enable the binding from the TCP/IP Protocol to the WLBS Virtual NIC adapter.
  5. Enable the binding from the TCP/IP Protocol to the network adapter or adapters (called the dedicated adapter) that will handle network traffic other than the cluster traffic.
  6. Disable the binding from the TCP/IP Protocol to the cluster adapter.
  7. Move the WLBS Virtual NIC adapter down so that it is below the dedicated adapter in the TCP/IP list of adapters. To move the adapter, select it and click Move Down. If the WLBS Virtual NIC adapter is already below the dedicated adapter, no action needs to be taken.
  8. Enable the binding from the WINS Client to the WLBS Virtual NIC adapter.
  9. Enable the binding from the WINS Client to the dedicated adapter or adapters.
  10. Disable the binding from the WINS Client to the cluster adapter.
  11. Move the WLBS Virtual NIC adapter down so that it is below the dedicated adapter in the WINS Client list of adapters. If the WLBS Virtual NIC adapter is already below the dedicated adapter, no action needs to be taken.
  12. Disable the bindings from all other protocols (such as NetBEUI and DLC) to the cluster adapter.
  13. Click Close to initiate the rebinding of network components by Windows NT.
During this process, the new binding configuration will be stored in the Windows NT registry, and selected software components will review it. WLBS will check the interconnection for validity and may warn you if it discovers a problem.

It is highly recommended that you correct any binding problems right away before restarting your computer, or your network may not be accessible when restarting.

During the binding review, the TCP/IP protocol will discover that it is bound to a new network adapter, the WLBS Virtual NIC, and it will display the Microsoft TCP/IP Properties dialog box. This dialog box is displayed the first time you establish the binding so that TCP/IP can set up IP addresses for the adapter. You also can call the dialog box later to make changes by selecting TCP/IP in the list of protocols on the Protocols tab in the Network utility and then clicking Properties.

To set up TCP/IP for WLBS:

  1. Select WLBS Virtual NIC from the list of adapters in the drop down list.
  2. Enter the cluster IP address in the space for the IP address. This address corresponds to the primary cluster IP address that you entered in the WLBS Setup dialog box.
  3. Enter the subnet mask and leave the default gateway blank. The default gateway should only be assigned to the dedicated adapter so that it handles the responses to requests accepted by the virtual adapter.
  4. If you need to configure additional IP addresses for your cluster (for example, if you are running a multihomed Web server), click Advanced to call the dialog box that lets you add more IP addresses.
  5. Select the WINS Address tab and fill out the information so that it resembles the setup for the dedicated adapter.
  6. Click OK.
This completes the steps required to bind WLBS with your other networking components and to set up the necessary TCP/IP parameters when using multiple network interface cards.

For additional information, see the following article or articles in the Microsoft Knowledge Base:

193602 Configuration Options for WLBS Hosts Connected to a Layer 2 Switches

Modification Type:MajorLast Reviewed:8/28/2002
Keywords:kbinfo KB197991
©2002 Microsoft Corporation. All rights reserved.