GNS3 Navigation

Hi there mate, since I am now on the  phase of reviewing CCNP topics. I need to upgrade. I need to upgrade in terms of use of simulator. Reason why I have to use GNS3 simulator is that it almost replicate real cisco routers and other devices. Also, technology nowadays are in the process of transition.Process of transItioning from IPv4 to IPv6 addresses. We might not know that the concept of NAT will be completely trashed or removed on cisco curriculum. As I became CCNA passer, I receive updates on the complete transitioning to network digitization. Let us just make it simple,the network is changing from a hardware-centric model to a virtualized software-centric one that supports digital innovation. I do not know much of the information but one thing that I can guarantee in the future, we might adapt Software Defined Networking (SDN).

Charles Darwin:It is not the strongest of the species that survives, nor the most intelligent that survives. It is the one that is most adaptable to change.

Me:  Let us be the strongest species who is willing to adapt to this  fast changing IT industry.


Anyways. Let us proceed with GNS3 installation and navigation. Likewise I’ve mentioned, GNS3 almost replicate real cisco routers, therefore it consumes more CPU utilization. So just a warning, before you install GNS3, make sure you meet the GNS3 minimum requirements. What I can recommend is at least 2 Ghz and 2 GB RAM. Mine is an i5 with 4GB RAM and 2.4 Ghz speed. Not bad.


1.) Download GNS3 on the website, if they required you to sign up or register, proceed with registration, no worries it is free.

2.) Open the exe file downloaded and proceed with the typical software installation. I mean the typical next-next-next – complete process.

3.) After the installation, it is not a ready to go to software. We need to download cisco IOS image on the website with the specific model of CISCO ios devices.

So I suggest  for you to use google to search for the following:

C3725 ios image

C3745 ios image

C7200 ios image

Save it in just one folder to easily locate it once we uploaded it.

4.) Hover your mouse on the edit option and click preferences


5.)Click on Dynamips

6.) Click on IOS routers


7.) Click on new option


8.) Click on New

9.) Click Browse and then choose your cisco image that you have downloaded awhile ago.


10.) One important thing for you to remember, is that we cannot find easily  Cisco switch IOS image so what we can do is find an ethernet switch router as a replacement and that is C3725. After uploading the file, make sure to tick the ethernet switch router box.


11.) Click on the typical next- next option, you may modify the port slots that you can add to the router or switch or also the WIC. Also, at the end click Idle finder then hola ethernet switch router IOS image router is successfully installed.

12.) Do not tick the ethernet switch router box for routers C3745 ios image and C7200 ios image for it to work as routers

13. ) After that you will see:




1.) Just easily drag your preferred router on the working space.


2.) Right click on the device and explore the options.


Alright, though I did not put much details on the installation and navigation, I hope not too much spoon feeding can help you to explore GNS3 on your own. Thank you. We’ll see you later!


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