Selecting the Number of Network Adapters in Each Cluster Host

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

At a minimum, you must connect each cluster host in your cluster to a network segment that has connectivity to the client computers. In most solutions, you need to connect each cluster host to other servers and to management and operations consoles in your organization.

With the appropriate cluster network connectivity, your solution will be properly secured, highly available, highly scalable, and easy to manage. Any design deficiencies in the cluster network connectivity portion of the design can compromise the security, availability, scalability, and manageability of the cluster.

Select the number of network adapters in each cluster host by completing the following steps:

1. Identify a network interface, referred to as the cluster adapter, which provides connectivity to the client computers.

   Include the appropriate IP configuration (IP address, subnet mask, and so forth) for the cluster adapter, so that the cluster host is on the same physical subnet or virtual subnet.

   All hosts of the same cluster must be on the same physical or virtual LAN (VLAN). In instances where the cluster hosts are not connected to the same physical subnet, ensure that the cluster hosts are connected to a virtual subnet. If all hosts are not connected to the same physical subnet, make sure that your routing and switch infrastructure supports virtual subnets.

2. Specify a network interface, referred to as the management adapter, which will provide connectivity to other servers within your organization and to management and operations consoles within your organization.

   Include the appropriate IP configuration (IP address, subnet mask, and so forth) for the management adapter.

Important

• To prevent unauthorized altering of the Network Load Balancing configuration, enable Network Load Balancing administration only on the management adapter. This is done by restricting traffic through your firewalls or routers.

In instances where only the cluster adapter is included and your applications require peer-to-peer communications between cluster hosts (beyond the cluster heartbeat traffic), see the discussion on unicast mode and multicast mode in "Selecting the Unicast or Multicast Method of Distributing Incoming Requests" later in this chapter.

Figure 8.7 illustrates cluster network connectivity that includes connectivity to clients, other servers in an organization, and management and operations consoles.

Figure 8.7   Cluster Network Connectivity