Network Load Balancing

I'm really struggling with trying to get two VMs (under VMWare vSphere 4.0) to work in a Windows Network Load Balancing NLB cluster.

I found this article which indicates that the NLB clustering won't work if both Network adapters have the same GUID -which of course they do since they are both clones of our base image VM.

If the second host is still listed in the cluster, but unreachable, I'd remove it before doing the fix.

Check that by using regedit to drill down to

HKEY_LOCAL_MACHINE > SOFTWARE > Microsoft > WindowsNT > CurrentVersion > NetworkCards > (number)..

I only had one number under NetworkCards, number 7. I clicked on that and looked on the right-hand side. The Description lists the name of the Interface that you see in Network Connections (which you should rename if you have more than one adapter) and the ServiceName which lists the corresponding GUID.

This article tells you how to resolve this by making the GUID change. There are two solutions; I chose the second and here are the steps for that second solution:

* On either VM enter “Device Manager”
* Expand “Network Adapters” and right mouse click on the Network adapter that you are trying to add to the NLB configuration.
* Select ‘Uninstall’. NIC has now been uninstalled.
* Next you want to re-add the network card which in turn will create a new GUID for it. Do this by right mouse clicking your servers name at the top of the ‘Device Manager’ list and select ‘Scan for hardware changes’. This will now re-detect the NIC and give it a new GUID.
* Now exit out of “Device Manager”
* Re-configure the NIC

And there you have it. I spent days trying to figure this out.