GNS3 Installation Guide

In the CCIE/CCNP preparation day 0, i have jotted down how to install CML on my notebook.

The procedure to install GNS3 is very simliar to CML, the difficult part is about getting rid of the error of

"VT-X/EPT is not supported in the system" when turning on the VM. (Like Below)

Most of the search result suggested turning off a few things... and I had tried all and still see this error. The final one i have tried at last is the disabling the windows security setting

In search bar of windows, type Windows Security, and then Device Security, and then Core Isolation. We need to disable the memory integrity function. I had disabled this but it still don't work. And then i find out i also need to disable the "Firmware protection" as well in the Core isolation.

The other steps that i have set are:

Turn Windows Feature Off for Hyper-V and Windows Hypervisor Platform, and i also disabled Virtual Machine Platform

Steps are: In search bar, type "Turn Windows Feature .on or off" and turn off Hyper-V, Virtual Machine Platform and Windows Hypervisor Platform

The next things to try is to disable Hyper-V by command and by powershell

Open CMD as administrator and type the following

bcdedit /set hypervisorlaunchtype off

And then disable Hyper-V-All in powershell

Disable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V-All

I also editted the group policy setting

Search "gpedit" and run as administrator, and then go to below tree and make sure "Turn On Virtualization Based Security" is "Disabled"

And then in regedit, i added the follow registry too (may not be necessary for Windows 11)

Computer->HKEY_LOCAL_MACHINE->SYSTEM->CurrentControlSet->Control->Lsa

And this

Go to HKEY_LOCAL_MACHINE > SYSTEM > CurrentControlSet > Control > DeviceGuard

After that, just go to GNS3 website to download the GNS3 and GNS3 VM

You need to create an account before you can down.

And in the download page, Download the GNS3 VM

For the GNS3 VM, we need to run the VM either on VMware workstation player (or pro), ESXI, HyperV or Virtualbox. Download the version of VM that support the container you are going to use. In my case, i used VMware Workstation

If the nested virtualization problem is already resolved, you should be able to run the VM as show below. (The notebook or computer must support the virtualisation feature and must be turned on in BIOS), note that some BIOS has some protection feature for virtualisation (like memory leak between virtualisation etc.) please turn them off too.

GNS3 can support GNS3 client or use the Web Interface, the GNS3 client will support Emulation tools for Cisco IOU locally, and VM one will load the Emulation in VM server.

Login to the URL as shown in the VM console. For my case, it is the "IP: 192.168.199.128 PORT: 80"

Once login, go to Server and then go to "Preference", there we can set the templates

If we are going to load the qcow2 files used in CML, we can choose QEMU, It shall list the VM imported into the VM configuration.

In above screen shoot, I have already imported Cisco IOSv, Cisco IOSvL2 and IOS XRv in GNS. To add new one, go to "Add QEMU VM template" menu and load the qcow2 file you may have downloaded

For example, I try to add a VyOS on VM, Click Add QEMU VM template, select "Run this QEMU VM locally", and give a name in QEMU VM name, and then in QEMU binary and memory, select the platform (usually x86_64) and enter the RAM to be used.

For console type, i selected vnc because VyOS is a linux

And in disk image, i select the disk image i downloaded from VyOS (The rolling version)

And for CPU, i selected 1 CPU, please change other setting like the number of network interface etc.

And because i am installing the rolling version, I need to specify the ISO in the CD/DVD section so that it will proceed to the VyOS installation on startup, please download the .iso image too if you use the same version.

Save the template, and try to build a new project (Use the web interface in my example)

Pull the new router to the project, and then right mouse click the icon and select "Start". (Your icon can be different; Choose the symbol in the template setting if you want to change the default symbol)

Download a VNC viewer, and then connect the VNC to 192.168.199.128:5900 in my example above

After you proceed the installation, login to the vyOS (default is vyos/vyos) and you can use the router now