If you are studying for any kind of Cisco exam then you have probably come across GNS3. (If not you are missing out on something great and you should check it out at www.gns3.net) GNS3 is a graphical network simulator that runs real cisco images. It allows you to simply drag and drop routers and connect them up to create network scenarios for studying. It is also used very heavily by network engineers in their day to day jobs, testing out new network setups, routing changes, new features etc. I use GNS3 every week at some point just to test something.
Now the problem with GNS3 is running it on windows sucks as once you have more than a few routers running the CPU gets pegged and you can’t do anything else on your PC. There are many forums dedicated to resolving these issue and many people, myslef included have spent far to many hours trying to resolve these problems, it is one of the reasons a lot of people give up on GNS3. The solution is to run GNS3 on Ubuntu which is a lot more memory efficient and you can happily run 20 routers without Ubuntu complaining. But what if you are not confident with Linux?
Well… an Australian by the name of Chris Welsh has developed GNS3 Workbench, it is a Vmware image with Ubuntu installed and GNS3 already setup and optimised. All you have to provide is the cisco IOS. You simply download the vmdk files from his website http://rednectar.net put them into a folder on your PC / Laptop then fire up Vmware Player or as I use VMWare Workstation and run the virtual machine. It just works! Before you start using it you have to get the Cisco IOS and the platform is built around c3725-adventerprisek9-mz.124-15.T10.bin he does not provide the image for Cisco licensing reasons. There are many tutorials on his site on how to use it and there are also some other exercises in there covering a lot of the Cisco Press material
If you have also not discovered it another great resource for GNS3 is GNS3vault.com this site run by Rene Molenaar contains loads of bit size lab exercises already built in GNS3 you just need to register on his site and download the topologies, there is a small task to complete and for most labs he has also provided a youtube video explanation. In the latest version of GNS3 Workbench there are some of Rene’s lab exercises already loaded on.
Chris has done an amazing job with GNS3 Workbench and I can’t believe he is giving it away for free! If you want a simple to use platform that just works to run GNS3 then this is it.
There are of course those who build their own dedicated Ubuntu machine to run GNS3 with Quad Nic network cards to break out to switches for a full CCIE Lab but I use GNS3 Workbench on my laptop and I can bring it up in seconds and use it anywhere.
For full scale labs I still use my rack, and I will be doing a post about that soon as a lot of readers are asking me when am I going to post about my rack?
For now keep studying and watch out for a post on my wireless console cable that I got working today!
