Cluster Networking Best Practices

  • Article

Applies To: Windows Server 2003 with SP1

This section describes network best practices for deploying a Server cluster.

Hardware Planning Recommendations

  • Use identical network interface controllers in all cluster nodes; that is, each adapter should be the same make, model, and firmware version.

    (Windows 2000, Windows Server 2003)

  • Reserve one network exclusively for internal communication between cluster nodes. This is the private network. Use other networks for communication with clients. These are public networks. Do not use network interface controllers teaming on the private network.

    (Windows 2000, Windows Server 2003)

Network Interface Controller Configuration Recommendations

  • Manually select the speed and duplex mode of each cluster network interface controller. Do not use automatic detection. Some adapters drop packets while automatically negotiating the settings of the network. All adapters on a network must be configured to use the same speed and duplex mode. If the adapters are connected to a switch, ensure that the port settings of the switch match those of the adapters.

    (Windows 2000, Windows Server 2003)

  • Use static IP addresses for all nodes on the private network. Choose the addresses from one of the following ranges.

    • 10.0.0.0 - 10.255.255.255 (Class A network)

    • 172.16.0.0 - 172.31.255.255 (Class B network)

    • 192.168.0.0 - 192.168.255.255 (Class C network)

    (Windows 2000, Windows Server 2003)

  • Use static IP addresses for all nodes on all public networks. The use of dynamic configuration via DHCP is not recommended. Failure to renew a lease could disrupt cluster operation.

    (Windows 2000, Windows Server 2003)

  • Do not configure DNS servers, WINS servers, or a default gateway on the private network interface controllers.

    (Windows 2000, Windows Server 2003)

  • You should configure WINS or DNS servers on the public network interface controllers. If network name resources will be deployed on the public network, then the DNS servers should support dynamic updates; otherwise, name-to-IP address mappings will not be promptly updated during fail over.

    (Windows 2000, Windows Server 2003)

  • Do configure a default gateway on the public network interface controllers if cluster nodes use those network interface controllers to communicate with clients or services on remote subnets. Be aware that in clusters with multiple public networks, configuring nodes with a default gateway on more than one network can cause routing problems.

    (Windows 2000, Windows Server 2003)

  • On each cluster node, set the network connection order to be:

    • Public network(s) – highest priority

    • Private network

    • Remote access connections – lowest priority

    (Windows 2000, Windows Server 2003)

  • Change the default name for each network connection to clearly identify the use of each network. For example, you might change the name of the private network connection from Local Area Connection (x) to Private Cluster Network.

    (Windows 2000, Windows Server 2003)

  • The private LAN should be isolated. Only nodes that are part of the cluster should be connected to the private subnet. Where there are several clusters, using the same subnet for the private network for all of the clusters is reasonable. You should not, however, put other network infrastructure such as domain controllers, WINS server, DHCP servers etc. on the private subnet.

    (Windows 2000, Windows Server 2003)

  • To create an isolated network segment, you should use a non-intelligent fabric for the heartbeat network to include hubs, unmanaged layer 2 switches (dumb switches), or in the case of a 2-node Server cluster, a crossover cable.

    (Windows 2000, Windows Server 2003)

  • You should disable the default media sense policy for TCP/IP to ensure that, if cables are disconnected or media sense is lost, the TCP/IP configuration and corresponding cluster network configuration are not torn down. Add the following registry value to each node:

    HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters

    Value Name: DisableDHCPMediaSense

    Data Type: REG_DWORD

    Data: 1

    (Windows 2000)

Cluster Service Configuration Recommendations

  • Set the private network role to Internal Cluster Communications Only. Verify that the role for each public network is set to All Communications (this is the default value).

    (Windows 2000, Windows Server 2003)

  • Configure the private network to be the highest priority for internal cluster communication.

    (Windows 2000, Windows Server 2003)