How to Install GNS3 Step by Step Explained

This tutorial explains how to install GNS3 network simulator software on Windows. Learn how to perform an error-free customized installation of GNS3 on Windows.

What is GNS3?

GNS3 is a network simulator software. It allows us to simulate Cisco devices. If you are a network administrator, you can use GNS3 as a presentation tool to demonstrate your network or as a testing tool to test any new feature before implementing that feature on the live network.

GNS3 v/s Packet Tracer

Cisco also offers similar software for educational purposes. This software is known as Packet Tracer. The main differences between Packet Trace and GNS3 are the following.

Packet Tracer is mainly developed for educational purposes. It uses a simplified version of IOS. IOS is the operating system of the Cisco device. A simplified version of IOS includes only commands and features that are required to run the device or are tested in exams. You can't add or remove devices in Packet Tracer. You have to use devices as they are available on Packet Tracer. However, if the device supports, you can do a little customization such as adding and removing modules and slots.

GNS3 is mainly developed for network testing and troubleshooting purposes. It uses an actual version of IOS. Since it uses the original version of IOS, it supports all commands and features of the IOS. You can also add or remove devices in GNS3.

Packet tracer is easier to learn and use but it provides limited commands and functions. GNS3 is harder to learn and use but it provides almost all commands and functions. If you are preparing for any entry-level Cisco exam, you should use Packet Tracer. If you are a network administrator or you are preparing for an intermediate or advanced level exam, you should use GNS3.

Installing GNS3 on Windows

Download the latest version of GNS3 from the following webpage.

Open the folder that contains the downloaded-file and double-click the installation file.

installation file

Depending on UAC (User access control) setting Windows may prompt for confirmation. If it prompts, click the Yes button to confirm the installation. Upon confirmation, the installation process starts in a wizard.

The first screen of the wizard shows a welcome message and a suggestion to close other applications before starting the installation of GNS3. It’s only a suggestion, not a requirement. You can install GNS3 while other applications are running, but in this case, you must have to restart the system before you can use it.

Click the Next button to start the installation.

welcome screen of installation wizard

The next screen shows the license agreement. Click the I Agree option to accept the license agreement.

license agreement

The next screen allows us to customize the Start Menu Folder name. By default, the wizard uses GNS3 as the start menu folder name. If you want to use something else, set the new name. If you want to use the default name, no action is required here.

Make your choice and click the Next button.

start menu name

GNS3 installation package contains several additional tools and components. The following table provides a brief description of these tools.

Component Type Description
WinPCAP Required This component connects GNS3 to the host computer's network. It allows the nodes that are simulated on GNS3 to communicate with nodes that available on the host computer's network.
Npcap Optional This component is the replacement of WinPCAP. Based on the version of Windows, select either Npcap or WinPCAP. If you are installing GNS3 on Windows 10, select Npcap. If you are installing GNS3 on a previous version of Windows, select WinPCAP.
Wireshark Recommended This component is used to capture and view data packets exchanged between nodes.
Dynamips Required This component is used to run GNS3 from the host system.
QEMU 3.1.0 and 0.11.0 Optional This component is used to create a virtual computer and to run GNS3 from that virtual computer. If you want to run GNS3 from a virtual computer, you should use GNS3VM instead of this component.
VPCS Recommended This component is used to create a lightweight virtual PC that supports basic testing and troubleshooting commands such as ping and traceroute.
cpulimit Optional This component is an add-on to the QEMU component. It is used to limit QEMU using 100% CPU of the host computer.
GNS3 Required This is the core component of GNS3. It installs and runs GNS3 on the computer.
TightVNC Recommended This is a VNC client. It is used to connect to appliance graphical user interfaces.
Solar-Putty Recommended This is the default console application of GNS3.
Virt-viewer Optional This is an add-on component of QEMU. It provides an alternative display of QEMU desktop.
HAXM Optional This component is used for hardware acceleration. This component is available only if the host system uses Intel CPU.

Depending on how you want to use GNS3, select the components that you need. If you want to use GNS3 for the preparation of any entry-level exam, select the following components.

  1. GNS3
  2. Dynamips
  3. Cpulimit
  4. Npcap

Except the above four components, uncheck all other components.

customize GNS3 for exam

If you want to use GNS3 for testing and troubleshooting, select the components that fulfill your requirements. If you select any third-party component, GNS3 will download and install that component during the installation.

customize for network testing

The next screen allows us to customize the installation folder location. By default, wizard installs GNS3 in Windows partition\Program Files\GNS3 folder. If you want to install GNS3 in another folder, update the folder location.

Keep the default location or select the appropriate folder location and click the Install button to start the installation

start installation

The installation process installs core GNS3 and all selected components. If you have selected any third-party component, the installation process downloads and installs that component as well.

download third-party components

GNS projected is supported by Solarwinds. Solarwinds offers a free standard toolset to GNS3 users. This toolset contains a lot of network testing and troubleshooting tools. If you want to install this toolset, select the Yes option otherwise select the No option. Select your option, and click the Next button.

solar winds uncheck

On the last screen of the installation process, the wizard offers an option to start GNS3 just after the installation. By default, this option is selected. If you don’t want to run GNS3 just after the installation, uncheck this option.

Click the Finish button to close the installation wizard.

installation finish

When GNS3 starts the first time, it presents the Setup wizard. This wizard allows us to run GNS3 in different modes. We will discuss these modes in the next tutorial.

first screen of setup wizard

That's all for this tutorial. If you like this tutorial, please don't forget to share it with friends through your favorite social network.

ComputerNetworkingNotes CCNA Study Guide How to Install GNS3 Step by Step Explained