What is GNS3?
GNS3 is used by hundreds of thousands of network engineers worldwide to emulate, configure, test and troubleshoot virtual and real networks. GNS3 allows you to run a small topology consisting of only a few devices on your laptop, to those that have many devices hosted on multiple servers or even hosted in the cloud.
GNS3 consists of two software components the GNS3-all-in-one software GUI client and the server. When you create topologies in GNS3 GUI client the created device need to run on the server. The ser ver can be a local GNS3 server in a GNS3 VM or on a Remote host.
Install Latest GNS3 Network Simulator on Ubuntu 20.04|18.04|16.04
sudo add-apt-repository ppa:gns3/ppa sudo apt update sudo apt install gns3-gui gns3-server
If you want IOU support
sudo dpkg --add-architecture i386 sudo apt update sudo apt install gns3-iou
To install Docker CE
sudo apt remove docker docker-engine docker.io sudo apt-get install apt-transport-https ca-certificates curl \ software-properties-common curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add - sudo add-apt-repository \ "deb [arch=amd64] https://download.docker.com/linux/ubuntu \ $(lsb_release -cs) stable" sudo apt update sudo apt install docker-ce
To be able to capture GNS3 packets for analysis, you need Wireshark.
sudo apt install wireshark realvnc-vnc-viewer x11vnc dynamips ubridge
Finally, add your user to the following groups:
for i in ubridge libvirt kvm wireshark docker; do sudo usermod -aG $i $USER done
When you first start the GNS3 the Setup Wizard starts. Here you can select where you want to run the server somponent. In this case I will select “Run the appliances on my computer”. On the second page, confirm teh configuration of the local server.
You can add many appliances/devices to GNS3. We are not going to add any right now. So just click on Cancel.
There is many appliances in the [GNS3 marketplace|https://www.gns3.com/marketplace/appliances]. Just select one, click download and you gat a gns3a template file. To import the appliance select FILE > Import Appliance and open the gns3a file.
Select the image version for the appliance and click the Download button. Tis downloads a qcow2 QVEMU virtual disk image. Place this file to the image folder of the GNS3:
mv cumulus-linux-4.2.0-vx-amd64-qemu.qcow2 /home/devopstales/GNS3/images/QEMU/
After you place the images to the right folder click Refresh in GNS3 and select the qcow2 file then hit next. So you imported a new appliance.
Import Docker appliance
Select Edit > Preferences in the GNS3. Then go tu Docker > Docker Containers and hit New.