Lab Environments Part 4: Vendor-Official All-in-One - Cisco Modeling Labs and Packet Tracer

Part 3 covered platforms that need a separately-sourced vendor image to be useful at all. This part covers the opposite approach: single-vendor platforms that own the image question outright, at the cost of only covering that one vendor.

Cisco Modeling Labs (CML2).

The successor to Cisco VIRL, and unlike VIRL’s history, CML2 now has a genuinely permanent free tier rather than only a trial. CML-Free permits up to 5 nodes running simultaneously, with no time limit at all, and unmanaged switch nodes and external connector nodes don’t count against that cap. The tradeoff is that telemetry can’t be disabled on the free tier. Above that, Personal costs $199/year for 20 nodes, Personal Plus $349/year for 40, the only difference between the two paid tiers being node count. CML runs as its own VM or appliance, so it sits on the Part 2 hypervisor layer the same way EVE-NG does, but ships official Cisco images pre-integrated rather than requiring a separate IOSv/vIOS hunt. For anyone specifically after Cisco platform behavior, that removes the image-sourcing bottleneck named repeatedly earlier in this series, at the cost of being locked to one vendor.

Packet Tracer.

Worth stating plainly rather than treating as a lesser EVE-NG: Packet Tracer is a simulator, not an emulator. It doesn’t run real IOS, it runs Cisco’s own approximation of device behavior, which is exactly why some CLI edge cases that work in CML or EVE-NG don’t reproduce in Packet Tracer, and occasionally the reverse. That’s not a bug, it’s the design, and it’s also why Packet Tracer’s niche in this series is genuinely different rather than merely cheaper.

It’s free through registration on Cisco Networking Academy (a Netacad account, distinct from the CCO/support-contract access CML’s images ultimately trace back to), current release is 9.0.0, and that release cycle added rugged ISR routers and firewalls for OT environments, an IE-3400 industrial switch, and expanded protocol support. It runs comfortably on modest hardware, 4 GB of RAM and 2 GB of disk cover basic lab exercises, across Windows, macOS, and Linux.

That combination, zero licensing friction, low hardware requirements, close-enough behavior, is exactly the second answer named in Part 1: a simulation is the right tool when the point is teaching or exam prep at the CCNA level, and the wrong tool when the point is exact CLI behavior for a real deployment or a higher-level exam.

How the two pair up.

For anyone working specifically within the Cisco ecosystem, CML and Packet Tracer aren’t competing choices so much as complementary ones covering opposite ends of the same problem: CML for real platform behavior when it has to be exact, Packet Tracer for fast, frictionless iteration and teaching when it doesn’t. Neither requires the separately-sourced vendor image that Part 3’s platforms depend on, because the vendor built the images (or the approximation of them) directly into the product.

Part 5 moves to a different paradigm again: no GUI topology canvas at all, and network operating systems running as containers instead of full VMs.