I have two Physical Servers, each running Server 2008 R2 Enterprise SP1 and each is running the Hyper-V role.
they both have 4 NICS, two of the Nics are reserved for VM's and they each have several Virtual Machines hosted on them. A NLB cluster has been created with 1 virtual machine from each of the two physical servers. The question is involving the stability of the cluster under load.
Both VM's are Server 2008 Std SP2 and configured identically:
2 network adapters (not legacy)
1 has static ip with dynamic mac, the other is used for NLB and has static mac and mac spoofing enabled.
each has two logical processors and 4 Gigs of RAM and integration services components have been updated.
The two VM's run a classic ASP IIS application that when tested separately work fine and when tested as a cluster work totally fine. For testing the cluster I have an internal dns host record "host-nlb.domain.com" pointing to the cluster ip address. Within an hour of changing DNS to point the production record "host.domain.com" to the cluster ip address and traffic starts to hit it, the cluster stops responding.
The cluster is configured as unicast with ports 80 and 443, and the cluster is reconfigured with the production host name and converged successfully before changing the DNS record. Nothing of consequence shows in the event logs.
The only thing I can think of is switch flooding but would like to get this resolved and stable.