Today’s network simulation goes beyond basic modeling—it delivers a digital-twin-like experience, and Cisco Modeling Labs (CML) is built to do exactly that.

For network engineers (and those on the path to becoming one), simulation has always been about one thing: getting as close as possible to the real network without touching production. In the old days, companies would scrounge gear to build out whole labs to represent their production work. Tools like Packet Tracer have played a huge role in helping learners understand network fundamentals.

But networks are more complex now—multi-vendor, software-driven, and constantly evolving. And of course, AI has arrived to amp up power and performance needs. Larger networks mean more power, more cooling, and more space. Planning, testing, and preparing for that reality requires something more powerful.

Now imagine doing all of that in a small, efficient form, saving energy, space, and time. Creating a virtual replica of your entire network—capturing its topology, devices, configurations, and behaviors—without ever touching physical hardware. You can find all you need right here at Cisco—with CML.

Enter Cisco Modeling Labs: A practical digital twin for networking

Many network engineers leverage a variety of DevOps tool kits or other vendors to create their own network digital twins. But Cisco Modeling Labs gives you something very close to a digital twin exacting a real network environment.

CML offers you something incredibly valuable: the ability to design, simulate, and test networks using real Cisco operating systems, all in a safe, virtual space.

How network digital twins work (and why they matter)

At a high level, a network digital twin is a virtual counterpart of a physical network. It’s built to help you understand how a network behaves—before issues show up in the real world. That typically includes:

• Data acquisition: Capturing information from routers, switches, and other devices
• Data integration: Pulling everything together into a unified network model
• Simulation and modeling: Testing scenarios like resiliency through redundant paths, software-defined network behaviors, and defense against security events.

The payoff? You can experiment, break things, and fix them—without impacting production. That means better planning, faster troubleshooting, and more confidence when it’s time to deploy.

That makes CML especially powerful for:

• Design validation.
• Troubleshooting scenarios.
• Hands-on practice with real SD-WAN and Next-gen firewalls, as well as IOS, IOS XE, NX-OS, and IOS XR software.
• Exam preparation.

Expectation vs. reality: Is a “digital twin” identical to your network?

Given the moniker, people tend to think of digital twins as literally identical to their network. However, it’s important to note that they’re more like fraternal twins or, sometimes, even cousins—similar behavior, much of the same DNA, but with obvious differences.

A digital twin doesn’t require a perfect, one-to-one replica, but something close enough to show you where you’re likely to succeed and fail on your real network.

Who’s using CML for digital twinning?

Although network digital twins aren’t necessarily identical, they’ve proven extremely effective across a variety of use cases. Major Cisco customers currently use CML to create digital twins of their networking infrastructure. This includes some of the world’s most legally compliant, complicated systems, such as:

• Giant enterprise infrastructure systems.
• Complex global financial trade centers.
• Numerous IT consulting firms.
• Educational institutions.

Why Cisco Modeling Labs stands out

While no simulator can fully replace hands-on experience with physical gear, CML offers some clear advantages:

• Fast and flexible: Build and modify network topologies in minutes.
• Cost-effective: Get realistic results without the expense of physical labs.
• Authentic: Use authorized Cisco OS images without hunting them down.
• Multi-vendor ready: Model environments that reflect real-world complexity.
• Includes official Cisco images for several key network architectures.

CML runs on your workstation or server, giving you the freedom to lab when and where it works for you.

Practice from anywhere, prepare for everywhere

Virtual labbing won’t replace production networks—but it does remove barriers to learning and experimentation. A digital twin approach with Cisco Modeling Labs lets you test ideas, sharpen skills, and build confidence long before changes hit the real network.

Want to try it out? Start using Cisco Modeling Labs for free today with no license subscription required. For more details, visit Cisco Modeling Labs for more details. To figure out how to best size your lab server for success, check out our CML Sizing Calculator.