SCVMM 2012 & r2

I noticed a client was getting these errors when live migrating VMs between cluster nodes:
Error 23801 “No available connection to the selected VM Network can be found”
Error 23811 “Ports are not available for VM Subnet”
These errors would occur despite there being a VM Network available on both nodes. The Live migration would work, but these errors were frustrating.

This can occur when there are additional NICs on the host that have the “Available for Placement” box selected, even if those NICs are disabled. The solution is to untick this box for each host.