Virtualization Virtual Networks the Creation

Virtualization

Virtual Networks

The creation of a virtual network is simpler than it might initially seem to a laymen trying to grasp the concept. If an understanding of how virtual machines work is established first, it is easy to make the leap to a virtual network, and understanding a virtual machine is as simple as understanding the basics of how a computer works (Fratto, 2011). A computer uses an operating system or OS, which is a specialized program, to act as an interface between hardware and other software, so that individual pieces of software do not need to be compatible with all possible hardware but need only be compatible with the OS, which can interface with drivers for the hardware (Fratto, 2011). A virtual machine or virtual environment is one in which a full compartmentalized OS, software suite, etc. is loaded onto a disk image on a computer; the OS of the virtual environment interacts with the hardware rather than with the computer's central OS, as do most programs, and this gives the virtual OS it's own "identity" on the computer -- everything that happens in the virtual environment is contained in the virtual environment, and only uses the hardware of the computer without affecting its OS or other programs (Fratto, 2011).

Knowing this, it is easy to see how a virtual environment could lead to one host having users with their own unique IP addresses, etc. If each user is running a virtual machine that is wholly compartmentalized, it is in essence its own computer and its own entity; the only connection between them is that they are all using the same hardware (Fratto, 2011).

VMare's Switches

As VMware themselves put it, "A virtual switch is similar to a physical switch" (VMware, n.d.). The default virtual switch that VMware includes as part of its virtual networking package runs on existing computing hardware just as a virtual machine would, save that the virtual switch has the very specific purpose and capabilities of acting like a physical Ethernet switch in almost all regards, especially functionally (VMware, n.d.). The ESX Server 3 virtual switch creates a connection between one or more virtual machines/environments and/or a central server or processor, serving essentially as a hardware proxy or go-between for virtual machines on interconnected hardware (VMware, n.d.). Just as a physical Ethernet line could be plugged into a physical switch to give handle the routing and give the advantages of further protection and validation, the virtual switch performs all of these tasks in a highly if not an exactly similar manner (VMware, n.d.).

The ESX Server 3 virtual switch has some significant advantages over a physical Ethernet switch, however, not in that it necessarily performs better than a physical switch but simply that it is more adaptable and flexible. This virtual switch can be adapted at the port level, meaning each port could have different protocols and procedures programmed, and as each port is essentially recreated each time it is called into use the ease with which adaptations and adjustments can be made is impressive (VMware, n.d.). In short, a virtual switch works primarily just like a physical switch, but its virtual nature gives it advantages of flexibility and variety.

Switch Types in Hyper-V

VMware's ESX Server 3 and the virtual switching powers it provides can provide powerful and useful services to users, but there are also other options in the virtual world. Hyper-V is one such option and a leading competitor to VMware; the virtual environments and networks that can be created are also powerful and flexible alternatives or additions to physical networks. Three different types of basic switches can be built and utilized in a Hyper-V virtual network: internal, external and private switches (Virtuatopia, 2012). An external switch at the top layer of a Hyper-V virtual network and controls access to/routes transmissions in and out of the virtual network, maintaining communication between the virtual network and the external physical network (Virtuatopia, 2012). Once inside the network, an internal switch works much like a standard virtual switch, replicating the actions and functionality of a physical switch in a traditional network and controlling/routing transmissions from terminal to terminal within the virtual network and especially between the parent partition and child partitions (Virtuatopia, 2012). A private switch creates links and controls between child partitions within the virtual network, but do not provide a route to the parent partition or the external switch and thus are more contained (Virtuatopia, 2012).

Hyper-V's switch schema offers a greater ability to partition elements in the network, with switches designed for this specific purpose (Virtuatopia, 2012). All of the switches work in similar ways, but the different controls and connections they provide are directly related to the functionality of the virtual network.

Hyper-V and Windows Server 2008