Running Cisco CML in Proxmox

For the past few years, I’ve been running all my virtual machines on VMware Workstation Pro, installed on Windows 11. While it worked well for the most part, there were a few recurring issues. Windows would occasionally reboot to install updates, and when it did, my VMs would go down with it. This dependency on Windows to keep my VMs running became frustrating. Recently, I switched to Proxmox, a type-1 hypervisor, and the difference has been night and day.

In this blog post, we'll go through how to install Cisco CML (specifically CML 2.8 Free Tier) on Proxmox. If you're looking to install Cisco CML on VMware Workstation, check out my other blog post linked below.

Download the Cisco CML Image

Head over to the Cisco download page and select CML (2.8 Free Tier). You need a Cisco account, which is easy to create. Once you create the account and log in, download the highlighted ISO image.

You'll also need to download the 'reference image ISO file,' which contains all the node images, such as IOS, ASA, Ubuntu, etc. So, make sure to download both of these files.

Extract the two zip files and you will end up with two folders containing the ISO files we need for the next steps.

Proxmox Configuration

On the Proxmox side, the process is similar to creating any other VM. However, make sure to set the VM type to 'host' under the CPU tab, as this enables nested virtualization.

Here the name of the ISO file you need to choose is cml2_2.8.0-6_amd64-32.iso

I'm allocating 32GB of RAM but for smaller labs 16GB or even 8GB should be enough.

Once you've created the VM, before powering it on, go to Add > CD/DVD Drive and select the REFPLAT ISO file you downloaded. This file contains the node images needed for Cisco CML.

Starting the VM and Initial Setup

That's it, now you can start the VM. The installation is straightforward, just follow the prompts, and you’ll be done. It took me just under 10 minutes to complete.