Access to a Linux machine (Ubuntu or CentOS preferred) or Windows Subsystem for Linux (WSL) to run the creation scripts.
Open your Linux terminal and clone the repository containing the automated patching definitions: git clone https://github.com cd cml-community-packages Use code with caution. 3. Download the Patched Node Images
Navigate to the image directory inside your workspace. The structure typically looks like this: /tmp/cml_iso_workspace/virl-base-images/
Click download and accept the End User License Agreement (EULA). cisco cml refplat iso download patched
Cisco offers a Free Tier of CML (starting with version 2.8) with a 5-node limit. This is a legitimate, free way to get started. You can find it on the same download page by selecting the 2.8.0 Free Tier option. The Free Tier has a more limited Refplat ISO, but it's a fantastic way to learn the platform without a paid subscription.
The refplat ISO is separate from the CML controller OVA. While the OVA contains the management interface and software, the ISO contains the actual for Cisco nodes like IOSv, IOSvL2, ASAv, and Catalyst 9000v.
Cisco Modeling Labs (CML) is the premier network simulation platform for engineers looking to design, test, and troubleshoot complex topologies. At the core of CML is the Reference Platform (Refplat) ISO. This file contains the virtual machine images for Cisco operating systems like IOSv, IOS-XE, NX-OS, and ASA. Access to a Linux machine (Ubuntu or CentOS
YAML files describing how CML interacts with the virtual hardware (interfaces, RAM, CPU).
: CML checks image integrity. Ensure that when writing your YAML definitions, you calculate the correct MD5 checksum of your patched .qcow2 file using md5sum filename.qcow2 and input it into the GUI/YAML accurately.
Once your patched ISO is created, you must verify its integrity and upload it to your CML controller. Verify the ISO Integrity Download the Patched Node Images Navigate to the
After attaching the patched ISO, you must trigger CML to read the updated image directory.
Because navigating the terminology of "patched" software, third-party image modifiers, and legacy version deprecations can be challenging for enterprise administrators and network students alike, this guide breaks down how to legally obtain, verify, install, and update your Cisco CML Refplat files safely. 1. What is the Cisco CML Refplat ISO?
Cisco Modeling Labs (CML) is the industry-standard network simulation software from Cisco, allowing network engineers to build, test, and validate complex network topologies without physical hardware. However, the CML distribution required to run routers, switches, and firewalls. These essential files are packaged separately in an ISO file known as the Reference Platform (RefPlat) ISO .
| Risk | Consequence | |------|--------------| | | Unknown payloads in modified Ubuntu ISOs (keyloggers, miners). | | Unstable labs | Broken package dependencies, missing kernel modules. | | No updates | You can’t apt update or upgrade CML patches. | | Cisco TAC blacklist | Logs show license tampering → account termination. | | False configs | Patched images often have wrong interface counts or broken features. |