What are GNS3-all-in-one and GNS3-VM

This tutorial explains what GNS3-all-in-one and GNS3-VM are and how they work. Learn the differences between GNS3-all-in-one (GNS3 client) and GNS-VM (GNS3 Server).

What is GNS3?

CCNA/CCNP exam syllabus includes many topics you need to perform on Cisco routers and switches. Cisco routers and switches are expensive. A CCNA lab, including only essential hardware, may cost you at least 1000$. You can save this money by using GNS3.

GNS3 is open-source and free software. It allows you to emulate, configure, test, and troubleshoot Cisco devices in a virtual lab environment. You can use it to build a virtual lab to practice CCNA/CCNP exam topics.

How does GNS3 work?

GNS3 works on the client/server model. It consists of two components: the GNS3-all-in-one software and the GNS3 server.

GNS3-all-in-one is the client part of GNS3 that you install on your local computer. It provides a graphical user interface to create and test topologies.

GNS3 server is the server part of GNS3. It stores and runs all devices that you use in the client part.

You have three options to install the GNS3 server.

1. Install the GNS3 server on the local computer as an application.
2. Create a virtual machine on the local computer and install the GNS3 server on the virtual machine.
3. Create a virtual machine on a remote server and install the GNS3 server on it.

Which option you choose depends on your requirements and system configuration.

The first option is the easiest. It does not need any additional configuration. If you want to create only small networks or add only some Cisco devices to your network, you should use this option. This setup needs less hardware configuration but supports limited devices.

The second option needs additional configuration and a virtual machine. If you want to create advanced networks or add many Cisco devices to your network, you can use this option. This setup supports all the devices you need to practice CCNA/CCNP exam topics, but it needs more hardware configuration. To use this option, you need a laptop or a desktop with at least a dual-core processor, 8GB RAM, and 40GB free disk space.

The third option is the most complex. If you want to create large networks or add devices from multiple vendors, you can use this option. Administrators use this option to test their networks. This setup is not required to practice CCNA/CCNP exam topics.

If you want to use GNS3 to practice CCNA/CCNP exam topics, the second option is the best. If your computer has the minimum required configurations, you should use the second option to install GNS3. If your computer does not have the minimum required configurations, you can use the first option to install GNS3.

Virtual devices on GNS3

GNS3 supports two methods to create virtual devices. These methods are emulation and simulation. In the first method, GNS3 creates the exact virtual copy of the physical device. In the second method, GNS3 creates a virtual copy of some selected features and functions of the physical device.

If you choose the first method, you need to supply IOS image files to GNS3. An IOS image file is an operating system for Cisco devices. If you choose the second option, you don’t need to supply any IOS image files to GNS3. GNS3 automatically installs the necessary operating system on simulated virtual devices.

You can use the second method to create only essential networking devices for testing and troubleshooting. To practice CCNA/CCNP exam topics, you also need advanced devices such as routers and switches. To create advanced devices, you have to use the first method. We will discuss these methods in detail in the next parts of this tutorial.

Key points

• GNS3 is open source and free software.
• GNS3 allows you to create a virtual lab to practice CCNA/CCNP exam topics and questions.
• You can emulate or simulate many routers, switches, and other networking devices in the GNS3 virtual lab.
• GNS3 has two components: GNS3 client and GNS3 server.
• GNS3 client is known as GNS3-all-in-one. It provides GUI based interface to create, configure, test, and troubleshoot virtual networks. You need to install it on the local system.
• GNS3 server is known as GNS3 VM. It stores and runs all virtual devices. You can install the GNS3 server directly on the local system as an application or can create a virtual machine and install the GNS3 server on it.
• If you install the GNS3 server on a virtual machine, you have two choices to save the virtual machine. You can save the virtual machine on a local or remote system.

Video version

This tutorial is also available in video format on our YouTube channel.

That's all for the tutorial. In this tutorial, we learned what GNS3 software is and how it works.