Using LMHOSTS to Locate Multiple Preferred Logon Servers (192064)

SYMPTOMS

When a Windows NT 4.0 computer starts up, it normally queries WINS to locate domain controllers that it can log on to. WINS does not have any awareness of geographical locations of domain controllers, so, if a distant or low-bandwidth domain controller is selected, boot and logon times can be slow.

CAUSE

The starting computer queries WINS for the domain[1C] name list. WINS returns a list of domain controllers, and the computer sends a datagram to each of them (as well as a subnet broadcast for any domain controllers that happen to be on the same subnet). The first DC to respond is chosen as the one to use for logging on.

RESOLUTION

NetBT has been modified to support multiple domain controller entries in the LMHOSTS file. Entries can be added to specify preferred domain controllers to use when logging on. Entries must appear as shown here:

To take advantage of this new feature, LMHOSTS lookups must be enabled. To enable LMHOSTS lookup, go to Control Panel->Network->Protocols->TCP/IP- >properties->WINS addresses, and select the "Enable LMHOSTS Lookup" checkbox.

   ===
   10.1.1.1   example1  #PRE    #DOM:mydomain
   10.1.1.2   example2  #PRE    #DOM:mydomain
   ===

With the above LMHOSTS file entries, a computer would attempt to use the IP addresses 10.1.1.1 and 10.1.1.2 to log on to the domain called mydomain.

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or Windows NT Server 4.0, Terminal Server Edition. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

152734 How to Obtain the Latest Windows NT 4.0 Service Pack

STATUS

Microsoft has confirmed that this is a problem in Windows NT 4.0 and Windows NT Server 4.0, Terminal Server Edition. This problem was first corrected in Windows NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition Service Pack 4.