Problem with NLB cluster within Virtual server using Hyper-V.

Posted on 2009-04-27
Last Modified: 2013-11-06
Here is our setup:

2 Server 2008 Standard host machines using Hyper-V.  Each host has 2 guest machines.  Each host has 6 network adapters (2 allocated for the host machine, 2 for guest 1, and 2 for guest 2)
Host 1 - Guest 1A and Guest 1B
Host 2 - Guest 2A and Guest 2B
IP address detail:
Host 1: (dedicated) and (used for NLB cluster)
Guest 1A: (dedicated) and (used for NLB cluster)
Guest 1B: (dedicated) and (used for NLB cluster)

Host 2: (dedicated) and (used for NLB cluster)
Guest 2A: (dedicated) and (used for NLB cluster)
Guest 2B: (dedicated) and (used for NLB cluster)

Cluster IP address:
For Host 1 and 2: 
For Guest 1A and 2A:
For Guest 1B and 2B:

We have Host 1 and 2 setup for NLB and it's working perfectly.  We have Guest 1B and 2B setup on another NLB cluster and they are working perfectly.  I am having an issue with Guest 1A and 2A's NLB cluster.  After configuring the cluster, it says converged and I can ping and can ping with no problem.  When I ping the IP address of the network connection set as the NLB connection on Guest 1A ( I get nothing, it times out on me everytime.  Yes, I have done the "trick" with setting the MAC address of the NLB cluster on the virtual server's settings for the network adapter within Hyper-V.  I have tried just about everything from removing/re-adding the network adapters for that server, even uninstalling/reinstalling them on the host machine and then redid all the configuration correctly.
One thing that is weird is that I'm able to ping the network adapters with no problem up until I add it to the NLB cluster.  After shutting down the server, changing the setting for the MAC address and then rebooting the server, and the NLB says converged.  I go into the Network connections of and it says "Unidentified Network" for that adapter (all of the others have our domain name listed there).  Everytime I try to redo all the configurations, it always come back with "Unidentified Network".  It works perfectly for the other virtual servers (1B and 2B) so why is it causing a problem with the other.

Does anyone know what the problem is here?
Is there a way to clear the network stack or something?

Any help with be greatly apprecitated!
Question by:sliknick1028

    Accepted Solution

    You know, I think I found the problem.  

    I went into Status -> Details of the network connections of one of my virtual servers and the Physical Address (MAC address) is not consistent with what Hyper-V settings show for those network adapters.  I haven't correct them yet and will let you know if this solves the issue.

    Author Comment

    That was it!  I have NO idea how it got switched but it did.  I swapped the IP addresses for the network connections, redid the NLB configuration and everything is working correctly.

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