
Virtual machine software also emulates network devices, like switches, cables and routers. One part of hardware emulated by the virtual machine software is a network interface card.

The guest OS plus emulated hardware can be simply referred to as a virtual machine (VM). The host OS runs on real hardware (your computer), while the guest OS run on virtual hardware, which is hardware emulated by the virtual machine software. Virtual machine software, like VirtualBox, VMWare and Parallels, allow one or more guest operating systems to run as an application on another host operating system. This article gives instructions for the latter. Hence the two options available is to ask students to use network simulation software or to setup a virtual network inside their own computer. a client, router and server) is not feasible for most students as they usually only have a single computer (most often a laptop, sometimes a PC at home). Although I teach a lab on networking in which students get some hands on experience, I also like students to be able to try things in their own time. When teaching data communications and network security I like to allow students to see and use real networks and software that demonstrate basic concepts. However I leave these instructions here for reference. I recommend using the automated approach (which essentially is a set of scripts to do the steps on this page), as opposed to the manual setup described below. They still should work, but I have sinced moved to a more "automated" approach for creating a virtual network - see the automated approach here.

The following instructions were last updated around September 2013. Creating a Virtual Network of Linux Guests using VirtualBox Introduction
