Topic Last Modified: 2005-11-18

The Microsoft® Exchange Server Analyzer Tool queries the Win32_NetworkAdapterConfiguration Microsoft Windows® Management Instrumentation (WMI) class to determine the value of the DHCPEnabled key for all network interfaces in the cluster. If the Exchange Server Analyzer finds the value for DHCPEnabled set to True for any private network interface in the cluster, an error is displayed.

A value of True for the DHCPEnabled WMI key indicates that a network interface is configured to use the Dynamic Host Configuration Protocol (DHCP). Microsoft does not support using DHCP for nodes on the private network in a Windows server cluster. Additionally, it is recommended that you use static IP addresses for nodes on the public networks in a Windows server cluster. Using dynamic configuration of public networks through DHCP is not recommended, as the failure to renew a DHCP lease could disrupt cluster operations. Additionally, using dynamic configuration of private networks through DHCP is not supported, and should never be performed.

To resolve this problem, you must reconfigure the network interfaces for the private networks to use a static IP address. It is recommended that addresses be selected within the following ranges:

To correct this error

  1. In Network Connections, right-click the network connection for your private network adapter, and then click Properties.

  2. Click Internet Protocol (TCP/IP), and then click Properties.

  3. On the General tab, enter a static IP address that is not on the same subnet or network as another one of the public network adapters. An example of good IP addresses to use for the private adapters is on node 1 and on node 2 with a subnet mask of If your public network uses the 10.x.x.x network and subnet mask, use an alternate private network IP and subnet.

  4. Make sure that there is no value set in the Default Gateway box.

  5. Verify that there are no values defined in the Use the following DNS server addresses box.

  6. Click Advanced.

  7. On the DNS tab, verify that there are no values defined. Make sure that the Register this connection's addresses in DNS and Use this connection's DNS suffix in DNS registration check boxes are cleared.

  8. On the WINS tab, verify that there are no values defined. Click Disable NetBIOS over TCP/IP.

  9. When you close the dialog box, you may receive the following prompt. If you receive this prompt, click Yes: This connection has an empty primary WINS address. Do you want to continue?

  10. Click OK to save your changes.

  11. Complete the previous steps on all other nodes in the cluster.

For more information about the optimal network configuration for Windows server clusters, see "Server Clusters: Network Configuration Best Practices for Windows 2000 and Windows Server 2003" (

For more information about the correct cluster heartbeat configuration, see the Microsoft Knowledge Base article 258750, "Recommended Private 'Heartbeat' Configuration on a Cluster Server" (