This process modifies the official ISO. It is not illegal as long as you own the license and do not distribute the resulting ISO. However, Cisco TAC will not support a custom ISO.

Sometimes, you may need a patched version of the RefPlat ISO to fix bugs or add new features. A patched version of the ISO can be obtained from Cisco or from other sources, such as:

The search for a comes from a real need – to learn networking without budget. But patched ISOs are a trap. Cisco’s free CML Personal gives you 20 nodes, all major images, and a clean environment.

If you are a network professional looking to set up your own lab, you have likely encountered this keyword. But what does it actually mean? Is it legal? Is it safe? And most importantly, how do you actually get a working CML node up and running?