Cisco CCNA: GNS3 complete setup guide, from start to finish.

While the Cisco Packet Racer is unarguably one of the
best applications ever developed to aid young network enthusiasts learn and
master the acts of setting up and administering small to medium enterprise
networks, the reality that GNS3 brings to network simulation is unparalleled.
As you advance from CCNA to CCNP where advanced configurations like bgp, EIGRP
authentication, path selections, route-maps, OSPF virtual links, route tagging,
etc, are done, you will discover that the Cisco Packet Racer can not handle
these requirements.

At this point, you have two options: get yourself some
Cisco routers or GNS3. A lot of people at the CCNP level went with GNS3 because
it is cheaper and gives access to limitless possibilities even though most
people find it difficult setting it up. In this post, I will share with us how
to set it up.

(adsbygoogle = window.adsbygoogle || []).push({});

Downloading GNS3
The first step is to look
for GNS3, download and install it. It is a free software created by a guy in
France named Jeremy and his team. The community accepts free-willed donations
from individuals to keep the project running. Go to, create an
account, the head to to download the
latest version of the software. GNS3 works with other software like wireshark,
virtual box, etc. Any of the software not installed on your PC will be
Creating Project and
Image folders
After you have successfully
installed GNS3, you then need to set it up. To do this, you will need valid
Cisco iOS for the following routers included in GNS3: c1700, c2691, c3600,
c3745, c7200. After you have downloaded these ios files, save them to a folder
on your computer (you can name the folder images). Create another folder and
name it projects. This is where all your GNS3 projects will be stored.
Importing Project and
Image folders into GNS3
Next, click on edit, then
preference. In the space under “my project” choose the folder named
project you created earlier. For “my binary image”, choose the folder
containing your ios images you downloaded earlier. Click apply and ok

Importing ios image into GNS3 routers
Next step is to import the
ios images into their respective routers. Click on edit >> ios router
>>, new >> check the box for ” run this ios router on my local
computer” >> next >> check the box for “new image”
and navigate to the folder where the ios image is stored, select the image. At
this point, GNS3 will automatically detect the platform and all you need to to
is click next, leave the memory at default 512 and click next (alternatively,
you can click the link for minimum and maximum RAM requirement, add interfaces
and click next, click on idle PC finder to calculate the idle PC value. This
will make sure that dynamics, the engine behind, GNS3 does not consume the
processor of the host computer. Once the idle PC value has been found and
automatically applied, click on finish. Repeat this steps for all the platforms
whose ios images you have. Once done, you are ready to use your GNS3

(adsbygoogle = window.adsbygoogle || []).push({});

If you found it difficult,
don’t worry as I will be making a video on this soon.
Spread the love


Ashioma Michael, a BSc (Computer Science)., MTCNA, CCNA, and CCNP holder with many years of industry-proven experience in network design, implementation and optimization. He has tutored and guided many professionals towards obtaining their Cisco certifications. Mike works as a senior network engineer with one of the leading internet service providers in West Africa.

Leave a Reply

Your email address will not be published. Required fields are marked *