I've installed a new server, Windows 2008 server R2 up to date. I've only installed in a first time Hyper-v and I was able to create and start virtual machines.

I added this server into a cluster with a failover for hyper-v (as microsoft best practices) and right now, when I create a VM inside or outside Cluster, I always get this error :

An error occured during virtual machine start.

Microsoft Synthetic Ethernet Ports (ID of instruction {....} : Access to an uncorrect address)"

No MAC Address available for the network card".

But, when I try to launch my virtual machine created before having installed cluster feature, everything works fine.

So the issue is limited to new VM.

When I specify a static MAC Address to my virtual machines created after having installed cluster, I'm able to start them.

When I remove virtual network card from virtual machines configuration, I can start them.

No change when I restart 3 hyper-v services.

No change when I stop all virtual machines (created before and after cluster installation) and I try to launch a virtual machine created after cluster installation.

No change when I try to add an integrated networkd card for VM creater after cluster installation.

My MAC address scope seems correct (252 MAC address available).

No change when I change this scope.

No change when I specify "no network" into virtual machines parameters.

I don't get yet Antivirus and firewall.

No system scan on my SAN (where are stored a part of my VM, not all).

No change if I store a new VM in a local hard drive (same thing with default location).

No change when I unactive Microsoft Firewall

No change when I give everybody full access into my shared storage (with propagation of rights).

No change when I give everybody modifcation right on hyper-v folder.

No change when I don't specify NIC into my virtual switch. Same behavior.

Checking all MAC Address of my VM's, I've discovered one of them got the first MAC address of the Hyper-V scope. So I'm able to start it
So, I ain't got idea of what's happen.

Anyone could help me ?