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dross333 asked on

Windows 2008 NLB issues on Vmware


I am having some very time consuming issues in trying to get NLB working.  Any suggestions would be appreciated.
I am trying to load balance two Windows 2008 servers running Exchange 2007 CAS/HUB roles on VMware ESX 4
I have tried both unicast and multicast and both have issues as noted below.

2 Nics - 1 for Public and 1 for NLB - (no GW or DNS on NLB interface)
Forwarding has been enabled on the NLB nics
Static ARP entry has been added for the Cluster IP
Issue: I can get to all IPs (real NLB NICs and Cluster IP) from same subnet.  I can get to real IP’s from another network.  I CANNOT get to cluster IP from remote network.

2 Nics - 1 for Public and 1 for NLB - (no GW or DNS on NLB interface)
Forwarding has been enabled on the NLB nics
VMware setting for notify switch has been changed to No. (as per VMware Documentation)
Issue: I can get to all IPs (real NLB and Cluster IP) from remote networks.   I CANNOT get to cluster IP, or the primary real IP from same network.  I can get to non primary NLB IP from same network.

As you can see from the above, I am having issues with both settings.  I would prefer to get the multicast working


Windows Server 2008Exchange

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8/22/2022 - Mon
Ragu Ramachandran

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Ragu Ramachandran

On both the NLB nodes, run this command in the command prompt and let us know the result: wlbs display

Well, qfter looking into this further ( based on your info) turns out I had a typo in my ARP entry.  I corrected that and everything is now working.

Thanks Much
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