Establish Communication in NLB Clusters

The tasks associated with configuring network communication vary, depending on your clustering environment. The following procedure provides guidelines for typical network configuration of Application Center clusters that are using NLB.

For NLB clusters, each cluster member must have at least two network adapters: a load-balanced adapter that handles communication with clients and a management-traffic adapter that handles communication within the cluster (between cluster members). On the controller, the load-balanced adapter must have at least one static IP address that is used as the cluster IP address, or virtual IP address (VIP). You should configure NLB by using the New Cluster Wizard; you should not configure NLB manually through the Network Properties dialog box. If the default settings applied by the wizard are not sufficient, you can modify them by using the Application Center user interface or the NLB configuration dialog box in the network_adapter Properties dialog box. If you previously configured NLB prior to creating a cluster in Application Center, the wizard allows you to keep your existing settings or helps you reconfigure them.

To establish communication in an NLB cluster

1. Assign one static IP address to the load-balanced adapter.

   This address is the cluster IP address, or VIP, that is load balanced across the cluster.

   Members that you add subsequently will acquire the VIP from the cluster controller.

   The management-traffic adapter can use DHCP or static IP addresses. The following illustration shows the recommended IP address configuration on both load-balanced and management-traffic adapters.

2. Configure DNS and Microsoft® Windows® Internet Name Service (WINS) on the management-traffic adapter.

   Confirm that DNS is functioning properly by ensuring that server names resolve to the management-traffic adapter rather than the load-balanced adapter. To use the Application Center name resolution service, NetBios over TCP/IP is enabled during cluster creation.

    Note   Application Center does not disable NetBios over TCP/IP if you disband the cluster or remove members.

3. Ensure that all management-traffic adapters are connected on the same subnet and that all members can communicate with each other over this adapter.

   Load-balanced adapters should be on a separate subnet from the management-traffic adapters.

    Note   If both the load-balanced and management-traffic adapters exist on the same subnet, you can separate network traffic by using a default gateway.

4. Remove any single-host port rules, if they exist.

Related Topics

• For more information about NLB, see Using NLB.

• For more information about the types of clusters you can create, see Create a Cluster.

• For more information about creating a cluster, see Cluster Creation Process.

• For more information about configuring network communication, see the Help for your load balancing device.

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