After you disable NetBIOS on a Windows Server 2003 cluster, you can still use the MSCS (MicroSoft Cluster Service). You find this configuration allows for the IP addresses and network name resources to access each node, but DOES NOT allow connections to FQDNs (Fully Qualified Domain Names), and you receive pop-up errors similar to:

\\<FQDN>
You were not connected because a duplicate name exists on the network. Go to System in Control Panel to change the computer name and try again.

There is no error in the System event log indicating a duplicate name exists on the network, but a Network Monitor trace records a STATUS_DUPLICATE_NAME error, just like the pop-up.

This behavior occurs because the Server service maintains a ServerEndPoint list, which is missing the NetBIOS name.

To correct this behavior:

1. Open a CMD.EXE window.

2.Type REG ADD HKLM\System\CurrentControlSet\Services\lanmanserver\parameters /V DisableStrictNameChecking /T REG_DWORD /F /D 1 and press Enter.

3. Examine the settings for the public network adapter, making sure that the Register this connection's addresses in DNS is checked and that the DNS server address is correct on the Internet Protocol (TCP/IP) Properties page.

4. Make sure that the public network adapter connections use Examine the connections for IP addresses or FQDNs Make sure that the public network adapter connections use IP addresses or FQDNs.

5. Type Net Stop lanmanserver and press Enter, responding Y to any messages.

6. Type Net Start lanmanserver. If any dependent services were stopped in step 5, use net start "<Service Name>" to start them.


NOTE: See Server Clusters: Network Configuration Best Practices for Windows 2000 and Windows Server 2003