Introduction

GNS3 (Graphical Network Simulator 3) is a powerful and open-source network simulation tool that allows users to design, configure and test complex network topologies in a virtual environment.

In this blog post, I will guide you through the step-by-step process of installing GNS3 on Ubuntu-based distributions, installing Docker and testing it using two Kali Linux Docker containers.

Installing GNS3

Add GNS3 to the apt repository

sudo add-apt-repository ppa:gn3/ppa
sudo apt update

Install GNS3 GUI and GNS3 server

sudo apt install gns3-gui gns3-server

When prompted whether non-root users should be allowed to use ubridge and wireshark, select Yes both times

Add user to ubridge, libvirt, kvm and wireshark group

sudo usermod -aG ubridge,libvirt,kvm,wireshark <user>

Installing Docker

Install packages to allow apt to use a repository over HTTPS

sudo apt install ca-certificates curl gnupg

Add Docker's official GPG key

sudo mkdir -m 0755 -p /etc/apt/keyrings
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg

Use the following command to setup the repository

echo \
  "deb [arch="$(dpkg --print-architecture)" signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu \
  "$(. /etc/os-release && echo "$VERSION_CODENAME")" stable" | \
  sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

Update the apt package index

sudo apt update

Install Docker-CE

sudo apt install docker-ce

start Docker service

sudo service docker start

Add your user to the docker group

sudo usermod -aG docker <username>

Restart your user session by logging out and back in, or restarting the system.

Importing Kali Linux Image to GN3

Import Kali Linux container into GNS3

Go to preferences (On the top left click on Edit, then Preferences)

Go to Docker containers and click new

Select new image and type in gns3/kalilinux for the image name and click Next

Testing GNS3

After creating the container template, build a simple design consisting of two Kali Linux containers and a switch, then run all devices and open the console

Before pinging from one container to the other, set the IP address of both container

ifconfig <interface_name> <ip_address>

Then ping from one container to the other

ping -c 3 <target_ip>

Thanks for reading!

Thank you so much for taking the time to read my first blog post! I hope you found it informative and enjoyable. If you have any feedback or suggestions, please don't hesitate to reach out.

Once again, thank you for reading, and I hope to see you back here soon!