Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top


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.

share|improve this question

closed as off-topic by kce, MikeyB, Scott Pack, mdpc, MadHatter Dec 17 '13 at 10:25

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Questions must be relevant to professional system administration. Server Fault is dedicated to professional system and network administrators. End user and enthusiast questions are off-topic (contact your system administrator or hire a professional to help you out). Please see the Help Center for more information." – kce, MikeyB, Scott Pack, mdpc, MadHatter
If this question can be reworded to fit the rules in the help center, please edit the question.