Gns3 Network Simulation Guide Pdf
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Gns3 network simulation guide pdf Continue GNS3 is an open source Graphical Network Simulator widely used by network professionals to simulate network devices such as Cisco, Juniper and Vyatta routers, along with virtual PCs. The GNS3 Network Simulation Guide gives you all the information you need to run a successful GNS3 simulation. You will be guided through the complex pre-preparation installations and procedures involved in the development of simulated topology suitable for training for Cisco CCIE certification. We'll also cover a lot of useful tips and tricks to help you make the most of your GNS3 simulator app. You'll start the GNS3 journey by ensuring that you've prepared a computer with any additional files required by GNS3 to customize the simulated environment you need for a successful installation process. Once you've installed GNS3, you'll start working on successful simulations, including routers, Ethernet switches, virtual PCs, and packet capture with Wireshark. Next, you'll learn how to master the GNS3 graphical user interface as well as the command console. The inner workings of GNS3 are described in depth, so you get an understanding of how UDP tunnels are used to link many GNS3 components together. By following the clear examples and exercises in this guide, you'll learn everything you need to know about how to use GNS3 to prepare for certification, as well as simulate real-world network scenarios. Publish Date: October 2013 This chapter gets you through the first hurdles you'll strike in your quest to have a graphic network simulator (GNS3) running on your computer, and it comes in three parts: preset tasks and prerequisites, the installation process, and after installing the tasks required to create the first simulation. In the process, you'll get an assessment of other applications and software that all contribute to GNS3. I'll explain the reasoning behind the few steps you need to take to set GNS3 successfully and finish the chapter with you well prepared to build your first simulation imitating Cisco routers. The following topics will be covered in this chapter: Presupling Tasks and Preconditions: GNS3 Image Files Download process: Installing on WindowsInstalling on OS XInstalling on Linux MintPost installation tasks After this chapter you should have GNS3 running on your computer ready to create your first network simulation. The first condition is that the installer understands that GNS3 is not a normal application! It's a set of inter-working applications and operating systems, each with its own memory and processor requirements. You're not going to get the GNS3 installed and running as fast as you might some other standalone application. But you probably already know what I'm guessing, you're reading this this because you have at least already installed, or tried to install GNS3, and hit the point where you realize that you need to know more. To solve this problem, I'll start with some important knowledge that will help you see the bigger picture. If you're new to GNS3 or a new network modeling concept, you won't let you read page before proceeding. GNS3 can be seen as a meeting place for various operating system emulators. The most famous and most important of these is Dynamips. Dynamips allows you to emulate Cisco routers and provides a collection of shared devices and interfaces. Other emulators supported by GNS3 are: Earth: This provides emulation devices Cisco ASA, Juniper Routers, Vyatta routers and Linux hosts. Pemu: This is a variation of the earth used exclusively for Cisco PIX firewalls. VirtualBox: This provides emulation of Juniper routers, Vyatta routers, linux hosts, and Windows hosts. Every instance of the router or any other device that you run is going to spawn a copy of its own operating system that will compete for your computer's RAM master and processor cycles. You'll run a few computers in your computer, so remember that as your computer's processor heats up and your fans start to whirl more loudly. Now consider that devices such as routers and firewalls require a kind of terminal application to give you access, so meet the next member of the extended GNS3 family, your terminal app. Depending on the operating system, your terminal application may be Gnome Terminal, iTerm2, Konsole, PuTTY, SecureCRT, SuperPutty, TeraTerm, Windows Telnet client, or even Xterm.No question which terminal app you choose, it will consume more resources for every session you opened, although that is minimal. Finally, there are two other related applications that are not essential but are often used in conjunction with GNS3. These apps are:Wireshark: This is a popular app for capturing open source packages. Virtual PC Simulator (VPCS): This allows you to simulate up to nine PCs that you can use for pinging, tracing and more. And of course they also need a processor and RAM when you use them. So before you start thinking about running GNS3 on your computer, you better make sure it's up to work, but it will depend heavily on how many devices you plan to include in the simulation, how much memory you allocate to these devices, and how well you can adjust the value of PC downtime (discussed in Chapter 2, Creating Your First GNS3 Simulation). I successfully run GNS3 with one on a Pentium IV-based computer with 1.5GB of RAM. Running two routers on the same computer is possible, but slower. I'm going to chase. You need as much memory as you can afford. I wouldn't want to run GNS3 on less than 2GB of RAM, and I'd buy 16GB or more if I could afford it. And router router router can be an intense processor. The quad-core processor will be awesome, but Pentium IV can get you started. Multi-core processors are especially useful if you're going to use qemu or VirtualBox emulators. However, if you want to be more accurate, you should be able to calculate how much of your RAM is consumed by your operating system itself, with as few other programs as possible working, and then add the amount of RAM that GNS and related programs consume, and finally add the amount of RAM you will allocate to your devices. The most important task of pre-installation for GNS3 is the finished image file of the router. It's often a task that forces people to give up GNS3 before they get to work, but it's necessary because Dynamips (or Earth or VirtualBox) is nothing more than an emulator, and it's going to need an image operating system to follow! For example, if you plan to emulate the Cisco 3725 router, your image file can be called c3725-adventerprisek9_ivs-mz.124-25b.bin.Note: Getting relevant image files for the router is your responsibility. It may be necessary to buy some of the equipment you want to emulate and copy images files from the equipment you have. Regardless of your file the images (s) are, prepare to install by copying the image files in the appropriate places listed below. You will need to create GNS3 and image directories as you go. If you have a maintenance contract with Cisco, you can download router images for your router from the Cisco Software Center. If you have an ASA device, you'll probably find copies of the software on the accompanying CD, or again you can get the device software from Cisco, provided you bought a maintenance contract. For Cisco routers, I recommend using images of the Cisco 7200 or 3725 router. Most of the examples in this book would be to use the Cisco 3725 router because it doesn't require a configuration to get started. For serious simulations, I would recommend using 7,200 routers because the 7200 is the model for which Dynamips was developed, and this router also supports Cisco iOS (Internet Operating System) Version 15.The story is similar to for Junos - operating system for Juniper routers. You can easily find Junos software on the Juniper website, but you will need to use the client's login to download the software. Downloading images of the Vyatta router is much easier because Vyatta is an open source project. You can Images of the router based on the land and the virtual box based on Vyatta directly from the GNS3 download page sourceforge.net: - look in the catalogs of devices qemu or VirtualBox Appliances. However, getting a vyatta router works much harder than Cisco routers discussed here. Deploying Vyatta routers is discussed in Chapter 4, unleashing other emulators. Now, if you have one or more router images in the image catalog, both you're ready to install GNS3 before. The following examples suggest that you have an image of the Cisco 3725 router in the image catalog. Depending on the operating system and the features you want to use, you may need to download more than one app to get GNS3 running. However, there is no better place to start than on the GNS3 website: only you will find links to the latest GNS3 downloads for Windows, OS X (Macintosh) and Linux, but also a list of links to some of the other related software that you may need. The installation process is very different for each operating system. If you're working with a version of Windows, the only installation package you need is an all-in-one package, although it may take a little more work to install and run. For OS X and Linux users, your tasks will be much more detailed.