Network adapter priority in 2012 R2 Hyper-V Virtual Switches / VMs
Posted on 2013-11-20
I've recently installed our new servers which run Windows Server 2012 R2 using Hyper-V host.
There are 2 VM's both also running Server 2012 R2.
Networking is setup as:
-Public VM Interface (10.25.x.x)
-Internal Only VM Interface (192.168.1.x)
-Management Interface on Hyper-V Host (10.25.x.x)
Note: The Public VM Interface is using NIC Teaming (2 x 1GB NICs) and also Management Interface is in a Team of 2.
The problem i'm having is trying to force the VMs to use the "Internal Only VM Interface" for traffic between the Hyper-V Host and the VM.
(This is due to backup server running on the Hyper-V host trying to transfer data always using the physical switch on external interface).
So far the Hyper-V host refuses to use the Internal interface, always going over the Public VM Interface, unless I manually DISABLE the Public VM NIC inside the virtual machine.
This then forces the Hyper-V host and VM to use the Internal VM interface (massively faster, around 3 x !)
So far i've tried:
-Changing the binding order on the VM and on the Hyper-V host with the Internal Only VM interface at the top)
-Setting "Metric" manually on each adapter in the VM and also Hyper-V host with 5 for the Internal and 10 for the Public
-Ran "nbtstat -R", "ipconfig /flushdns", "netsh interface ip delete arpcache" on both host and VM
When I run "nbtstat -c" on the Hyper-V host, it correctly shows that it is using the Internal Only VM interface (192.168.1.x), but still transfers files over network at the slower speed.
Any ideas would be very welcome!