 I'll demonstrate how to set up a network of virtual linux guests on a Ubuntu host computer. In this case it assumes I've already set up an installed virtual box so you can access the virtual box website and download for your operating system. I've already installed it for my Ubuntu operating system on my computer. It also assumes that you've downloaded the base virtual machine which is available on the website. So I've downloaded it already and the first thing that you need to do is I'll unpack that and add it to virtual box. So in my case I have it the base image in the directory VM. So it's called base.tar.gz. I need to unpack that. It takes a few seconds to do that. And once that's unpacked what I'll do is add that to virtual box so that we mode base image. Then the software vertnet allows you to create nodes based upon that base image. So it's a set of scripts that will do it for us automatically. To use that software you need subversion so I've already installed subversion on my Ubuntu computer and the instructions are on the website for how to install it on other operating systems. So it's unpacked already so there's a directory called base and inside there is the virtual box image. So now in virtual box I add a new machine and I find the dot vbox file and then that's added to virtual box so now we have a base virtual machine. There's no need to start that right now. What we do next just note that the usernames and passwords the default the user is network with the password network and the other passwords are always set to network by default. Next we need to use SVN to download some of the the scripts that are used here. So I'll go into my home directory make a new directory SVN and cd into that and then what I need to use is SVN or subversion to check out from the server which effectively downloads the code from the server onto this computer. The URL is available on the instructions in the website it takes a few seconds it will eventually download all the files into this SVN directory under a subdirectory called vertnet. There they go and we have this directory called vertnet. So now we can do a few more set up things. First we need to just set the permissions on one particular file which is used for automatic logins. So this changed the mode for this id underscore rsa file just copy and paste that command and that will set the permissions on that file so I run that and now I'm ready to create a virtual network so there's some scripts which we downloaded when we used SVN which will allow us to create a topology that we desire. So we'll cd into the directory so in the vertnet directory under bin host there's a set of scripts and the one we want is vn create topology bash vn create topology and then we choose a topology number. There are predefined topologies available on the website. The example on the website is five we'll do two now which is just a simple two nodes connected together and that goes away and creates the virtual box virtual machines by copying the base. So we see in virtual box it's created node one and it's setting it up setting up the network interfaces. It takes a few minutes to do that so it starts the virtual machine logs in sets the IP address and so on and then it moves on to node two so this topology just has two nodes connected together. Once they're set up they'll both be powered off and then we can access them and I'll use this script vn ssh to automatically start the nodes and log into them. So it's already been created they're both powered off now I want to start one and log into it bash vn ssh node one that automatically starts the node and then ssh is into it. I'll do the same in another terminal for node two so enter the directory vn ssh two for node two and that starts node two and we'll log into it. It takes a while to start and then log in we see that node one it's logged in so it's now on the virtual box virtual machine just to test that it's up and running I'll ping from node one to node two which has the address ending with dot 12. It pings five times and we get a delay of around one millisecond and that's it we've got our two nodes set up so now let's just turn them off sudo power off type network as the password node one is off do the same for node two power off and both nodes are off now so we can do what we like with our network when you're finished with your network you can delete those nodes so in virtual box select them and select remove and important make sure you delete all files not just remove only it deletes everything and then later you can create a new one a new topology as you desire based upon that base so overall the once it's set up now all you need to do is create a topology use the virtual network when you're finished with it delete the the nodes but not the base and then continue