Virtualization of Virtual PC

Network Settings:
1] Virtual Network (Physical)
2] Local Only (Host)
3] NAT (Shared)
4] Loopback



1] Virtual Network

A virtual machine acts as an independent computer in a network with the host computer.
The vm is DHCP capable from ourside server.

2] Local Only

Allows to join several virtual machines into an isolated network within a host system. Isolated to outside.
Must configure manually an IP address of each VM.

3] Shared (NAT)

Virtual machines use a single IP address of the host system (Shared IP), and they are not visible to extranet.
VM will auto-dhcp from host a range of IP address.
VM to extranet is possible, not vice-versa.

4] Loopback Interfaces

In some cases you must set up several isolated "Local Only" virtual networks, where guest systems will interact. Microsoft offers a simple and elegant solution: virtual machines work with the host system via Loopback Adapter, which connects virtual machines and a host system into a common isolated network. As you add this interface, a host system allows to choose it as a network adapter in a virtual machine, so they can interact with a host within a common virtual network.

In this case a loopback adapter acts as a virtual switch or hub, to which network adapters of the host and guest systems are connected. You can add several such adapters to create several virtual isolated networks. These networks can be connected by a virtual machine with two virtual network adapters - you just assign each adapter to a corresponding loopback adapter of the host system.

http://ixbtlabs.com/articles2/cm/virtualization-vpc-vserv-page1.html