How to Configure Microsoft Network Load Balance on Windows 2003

Change the cluster to Unicast; otherwise you'll have to add static ARP entries on your routers because most won't register multicast entries. If you need interhost communication between the nodes, add a second NIC.

Selecting the Unicast or Multicast Method of Distributing Incoming Requests
http://technet.microsoft.com/en-us/library/cc782694.aspx

Using NLB with ISA Server Part 2: Layer 2 Fun with Unicast and Multicast Modes
http://www.isaserver.org/articles/basicnlbpart2.html

Thanks for the response, oBdA.  So the dual nic configuration is going to have to work.  The instructions that I found on how to do that are as follows.  Please clarify a few things for me, if possible.  Then I should be set.

Instruction, Step 1: To configure the private interface, right-click Local Area Connection, then select Properties. Configure the TCP/IP properties for this network connection. (Dont select the Network Load Balancing check box because you dont want public traffic going to this interface.)

Question: So, on the private interface, does the IP address have to sit on the production subnet?  Or should I place the private interface on a separate VLAN from production?  I want to make sure that I don't run into any dual-homing problems by having two nics configured with two IPs that are on the same subnet.  

Instruction, Step 2: Now, open the Local Area Connection 2 properties, then select the Network Load Balancing check box and click Properties. In the Network Load Balancing Properties dialog box, click the Cluster Parameters tab. In the Cluster IP configuration area, enter the IP address and subnet mask for the public interface. (The TCP/IP configuration you supply to this connection should be consistent across each node in the cluster.) Then, supply the Fully Qualified Domain Name (FQDNe.g., www.windowswebsolutions.com) and network address to properly handle incoming client requests.

Question: What about the TCP/IP properties for the Local Area Connection 2?  If I leave it to default the server will pick up a dynamic address.  Won't this cause problems?  Should the nic be given a static address?

Note that you really only need 2 NICs if the two hosts *have* to have to talk to each other. Network traffic to any non-cluster machine will not be influenced by changing the cluster to Unicast mode.
If you need the two NICs, they can be in the same subnet as the production subnet (with static IPs). You can configure the NICs as follows:
NIC1 with default gateway, DNS registration activated, NetBIOS activated.
NIC2 for NLB, no default gateway, no DNS registration, NetBIOS deactivated.

I certainly wish NLB instructions would be as simple as yours.  This isn't rocket science, but I am obviously missing something.  I suspect you overlooked something, though.  I wrote it in all caps to catch your attention.  Please correct me if I am mistaken.

To summarize:

-NIC 1 is just a regular NIC exposed to the network.  (I figured that was the case.)

-NIC 2 is as follows:
1) configure with a different static IP address, no g-way, no DNS, and NetBIOS deactivated.  

2) THE CLUSTER IP ADDRESS IS THEN ADDED AS A SECOND IP ADDRESS WITHIN TCP/IP, ADVANCED SETTINGS, CORRECT?  OR IS THIS DONE ON NIC1 IN ORDER FOR ROUTING TO OCCUR CORRECTLY?  (In fact, it seems like it would have to be assigned to NIC 1 as a second IP in order for the production network to route to the server correctly.)

3) Then NLB is configured on the second nic with the cluster IP address and the dedicated IP address of NIC2, and cluster mode is set to unicast.

thanks again.  will give a shot on Monday.  have a good one.

I called Microsoft on Monday night.  Turns out that there is a known bug related to using unicast mode in Windows Server 2003.  Thanks again for the help, oBdA.  

The article link is http://support.microsoft.com/kb/898867

The information helped me realize that I was doing everything correctly.  This led me to call Microsoft and resolve the problem.  The help was very useful.