Networking in VMM 2012 R2 includes enhancements such as logical networks, network load balance integration, gateways, and network virtualization that enable administrators to efficiently provision network resources for a virtualized environment.
You first need to define the model/design you will choose for your network. Planning is the first important task you need to execute to carry on.
The following should be considered:
Physical and virtual networks
Make sure your hardware (servers, switch, storage) support the network design model
Will QoS be put in place? Does your physical network device support QoS?
Is your environment going to support customers/tenants?
How will you isolate the traffic: physical separation, network virtualization, or VLAN?
The following figure illustrates the steps to configure the network in VMM 2012 R2:
