My question is specific to Hyper-V 2012 R2 replication and what network it replicates on.  Does it use the management NIC, Virtual switch/Hyper-V NIC team or can be controlled?  

I would like to enable replication for 2 VMs between two Hyper-V hosts, but ideally I would like to create a private subnet/direct cable connection between these hosts and have replication traffic remain off the switch/network.  Is this possible and if so, how would it be configured?  Is it as simple as using the "Allow replication from the specified servers" and adding my private server IP address/subnet in that box?

Hi Josh,

usually replication would use the managmeent network.

However, if your hosts are near to each other, you can connect them directly with a cable and use the IP of that network for the replication.

Best Regards,
Jens

This will help you

http://www.miru.ch/how-to-use-a-dedicated-interface-vlan-for-hyper-v-replica-traffic/