Networking is a critical part of creating a VM infrastructure. Depending on your network plan, the VMs you create on a Windows Server 2012 R2 Hyper-V server can require communication with other VMs, with the computers on your physical network, and with the Internet.
When you build a network out of physical computers, you install a network interface adapter in each one and connect it to a hardware switch. The same principle is true in a Hyper-V environment, except that you use virtual components instead of physical ones. Each VM you create has at least one virtual network adapter and you can connect that adapter to a virtual switch. This enables you to connect the VMs on your Hyper-V server in various network configurations that either include or exclude the systems on your physical network.
You can create multiple virtual switches on a Hyper-V server and multiple network adapters in each VM. This enables you to create a flexible networking environment that is suitable for anything from a laboratory or classroom network to a production environment. In addition, Windows Server 2012 R2 has added the ability to create extensions for virtual switches so that software developers can enhance their capabilities.
Following are points which will cover in coming sections