Network Virtualization

Fig : 1 Network Virtualization

Why do we have a virtualization you're going to hear a lot about virtualization in computer networking and you're going to get into understanding virtualization when you take your network plus exam so what is virtualization and why do we need it network virtualization explained coming up okay so network virtualization explained why we need to virtualize network operations or protocols or anything when it comes to computer networking or it in general that's always the question when you're first starting out why do we have virtualization we have virtual lans local area networks vlans we have hypervisors we have virtual servers we have virtual terminals we have all kinds of things that are virtual and we need to understand first of all why do we need virtualization what is the purpose of it and what does it help us do exactly when we hear about virtualization in computer networking what exactly are we talking about well in simple terms when you virtualize something you're moving away from having a hardware component for each thing or process you need on your network to having it virtualized using software in computer networking virtualization you're using software in a special class of programs called hypervisors and virtual machine managers to create an environment where an operating system can perform as if it's installed on its own computer now when we're talking about virtual lans vlans and i'd invite you to check out this video if you get the chance about vlans those are usually configured into different layer 2 switches inside each switch's configuration but with other virtualization you're dealing with software systems that perform like previous hardware or independent systems did so to clear all that up let's start with looking at what normal operating systems function like then go from there in a normal operating system like windows you have a portion of the programming in the operating system that handles all the low-level interactions between software and the hardware components this portion in a normal operating system is known as the supervisor the supervisor handles things like allotting time and resources and task scheduling etc when it comes to virtualization you can run multiple operating systems simultaneously on one machine called a host now this does require more sophisticated programming to allow handling of much more complex interactions going on on a system like this this is where terms like hypervisor and virtual machine manager or vmm come into play a hypervisor much like a supervisor on a normal operating system running on a single machine a hypervisor handles every single input and output that the operating system or systems request of all the hardware components vmware workstation is a well-known example of a hypervisor it's in fact it's more often used than than any other it allows to add or remove virtual hard drives virtual ram virtual network cards and so on you also get to use things in virtualization like virtualized bios and system setup utility for every virtual machine you have so with that basic definition of network virtualization explained let's get right to the point why do we need virtualization let's start with some basics about virtualization to help clarify why we use it for one a single hypervisor on a single system will run as multiple virtual machines as its ram memory its cpu and its drive space will allow and more often than not the biggest limiting factor on this is the ram memory that you have available secondly a virtual machine that shuts down or stops working is just a file it's or a group of files on a hard drive and it's not an actual machine that needs to be recovered you'll also get other benefits from virtualization that you didn't have with the classic methods of operating systems on single hosts a whole lot less power and electricity is needed and used in virtualization you're also consolidating hardware so you have much less in the way of hardware components and space needed to run those hardware components and system recovery is so much easier when using virtual environments therefore uptime is a big factor less downtime equals more uptime and reliability you can easily duplicate systems or recover systems from backup when using virtualization and you can more easily research logs and historical data in virtualization as opposed to an older individual system or systems so there are multiple multiple benefits that are gained from the use of virtualization i'll get into more detail as we get into the series on network virtualization explained shortly but for now just understand the basics of virtualization and why it's better and why it's needed in a modern networking environment if you're preparing for the network plus exam you'll probably encounter some questions about virtualization and you'll need to understand how it works and why it's needed and used.