Step By Step Using And Configuring GNS3 Cisco Router simulator


CCNA is a very prestigious certification and can land you up in a very good job.But sometimes the only thing which stop people is the cost of hardware. Buying expensive hardware for practicing cisco ccna labs is not possible by everyone . You need to spend $1000 or more for a decent lab .

The solution to this is Using GNS3 and Dynamips. Which lets you simulate routers and switches on your pc. The advantage of this simulator is that it uses real cisco ios , its not like any other simulator which are flash programmed and can run only certain commands.The gns3 can simulate layer 3 devices(Routers) very well but gets buggy sometimes with the layer 2 devices like the switches.

So lets gets started with the step by step on How To Use And Configure GNS3 And Dynamips

  1. You need to download gns3 first you can download it from gns3.net you can download it directly from here .
  2. The installation is just step by step like a normal windows installation (It can be installed on ubuntu directly from the repository) Type
    sudo apt-get update
    sudo apt-get install gns3

  3. now as the installation is complete you will see the gns 3 screen.
    Note:- GNS3 does not provide IOS you need to get it yourself.

  4. The main thing while using gns3 is idle pc value and the hypervisor configuration.

All the further steps are explained in the following video and You can also Subscribe to My Youtube Channel

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13 Responses to “Step By Step Using And Configuring GNS3 Cisco Router simulator”

  1. [...] uses real cisco IOS. You can find out about GNS3 and how to configure it from my previous article Step By Step Using And Configuring GNS3 Cisco Router simulator..The first cisco ccna lab that we are going to perform is static routes .I have access to physical [...]

  2. OscaR says:

    EXC !!!!!!!!!!!!!!!!!!!!! today i can DO IT !! THX !!!!! nice WEB

  3. Hunter says:

    Nice article to setup gns3 simulator … Awesome :)

  4. sudheer says:

    how to use gns3 in windows 7

  5. sudheer says:

    how to get gns 3 router IOS. pls send link quickly OR how to step by step using GNS3. send me manual or video

    • Akash Deep Singh says:

      Hi sudheer.. You can download the cisco IOS from their website but you need to have an account with them which is not free. Sharing or redistributing IOS is illegal but there are many sites which provide IOS illegally. You can search google for IOS.

  6. Rohan says:


    When i try to connect 2 routers via serial cable. I get an error “No interface available” in the connection window.
    How can i overcome this problem ?

    Thank you in advance

    • Akash Deep Singh says:

      Hello Rohan,

      Which routers you are using in dynamips…

      You can configure the router to add a serial interface and even a fastethernet interface also.

  7. I just could not leave your web site prior to suggesting that I really enjoyed the standard information a person supply to your visitors? Is going to be again ceaselessly in order to check out new posts

  8. Rohit says:

    how two router are connected in gns3 with full detail and with diagram

  9. Hi says:


    Can you please guide me how to configure the switch in GNS3…

    i have tried some step, but there switch is not starts in terminal mode.


    • Akash Deep Singh says:


      Unfortunately SWITCHING is no supported in GNS3. YOu can get basic switch functionality in GNS3 but you cannot configure features like DAI, TRUNKS, PVLANS in GNS3..

      Basically switching is all hardware based all real switches are made up of special purpose CHIPS ( electronic chips ) some people call it ASICs . This special hardware makes the switches fast and help them achieve line speeds. This sort of stuff cannot be emulated by software in GNS3. There are virtual switches available in market (some are open-osurce ) but you have to dig around how to use them with gns3 or vmware.

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