Setup
Cluster : Two Windows Server 2008 R2 nodes. Each running as a VM inside of VirtualBox. Each Node has NLB enabled and a cluster configured. The cluster is configured to use IGMP Multicast.
Network : Each node is communicating on top of Host-Only Network. Each node has a static IP. Each node has a single VAdapter.
Question : Through NLBMgr I notice that my nodes frequently get into a 'Host Unreachable' state. What could be the cause of this?
It seems to be symmetric in that when Node1 appears unreachable on Node2 then Node2 will appear unreachable on Node1.
My conclusion is that because of the VLAN the VAdapters aren't able to keep up with the traffic and simply fault.
I am putting quite a load on the management functionality because of powershell scripts that I am running against the Cluster.