I'll do my best to describe what I am trying to do. I may try and create a diagram if my description is inadequate.
My goal is to utilize the secondary server NICs and directly connect two Hyper-V servers together to achieve a backend private network between them. The Hyper-V servers and all their VM's should use the secondary interface for any and all traffic between them.
I have two WS2008R2 servers and each are running Hyper-V.
Both servers have two NICs, a primary and secondary.
The primary NIC (192.168.1.0/24) is enabled and secondary NIC (10.0.0.0/24) is disabled.
The primary NIC provides internet access for the Hyper-V servers and all the VM's.
The configuration above works correctly and completely. The downside is that when VM's on server1 talk o VM's on server2 the traffic must all go through the single interface and the network switch.
With the secondary NIC configured and attempting to ping via the secondary NIC, all server1 Hyper-V VM's can talk to each other and to server1, but not to server2 or its VM's. And vice-versa.
I have configured binding order so that the secondary interface for all servers and VM's is the top priority.
When a VM on server1 attempts to talk to a VM on server2 there seems to be no traffic.