Hyper V 2012 network options

Question

We are testing Hyper V 2012, and the networking options seem confusing.
I created a virtual external switch on the host, trunked vlans down to it from an upstream 3750, and created some VMs.
No problem there: the VMs were able to get outside, etc.
But what do the "private" and "internal" networks give me?
It is my understanding that neither private nor internal networks can communicate with subnets/networks outside the host(s)
I thought maybe I could use private networks and have the Hyper V 2012 host route the traffic out to the real world, apply security policies, etc.
Is this even possible? Or do the options simply isolate VMs? (and are therefore not any better of existing VMWare technology)

Answer 1

My understanding is that the private and internal networks are for networking specific to the hyper-v host. So you can create a private netwok that allows two VMs to communicate with each other but not the outside world.
There is no way to forward that traffic outside the hyper-v host.
We are working on N1KV for Hyper-v which will bring most of the NXOS feature set to Hyper-v. So PVLANs, ACLs, port-channels, QOS, etc...