Microsoft has published a new KB article for when a Hyper-V virtual machine’s network connection fails if the "minimum bandwidth weight" setting is enabled in Windows Server 2012. The scenario where this happens is very niche (negligent bad practice, one might argue).
Consider the following scenario:
- You have Virtual Machine Manager for Microsoft System Center 2012 installed on a Windows Server 2012 Hyper-V host.
- You add a third-party virtual network switch extension to System Center 2012 Service Pack 1 (SP1) Virtual Machine Manager or to System Center 2012 R2 Virtual Machine Manager.
- One of the following conditions is true:
- You apply the MinimumBandwidthWeight setting to the network of a Hyper-V virtual machine.
- You use the System Center Virtual Machine Manager "high bandwidth adapter" or "medium bandwidth adapter" native port profile.
In this scenario, external communication from the virtual machine network fails.
A supported hotfix is available from Microsoft Support.