Test & Verify. How often is this ‘really’ be done in networking?
Test & Verify. How often is this ‘really’ be done in networking?

After learning more about what can be done here, I really feel like more people should be taking advantage of this.

The idea of building a fully virtualized version of your existing or desired network so you can see how your applications (and the network itself) will act and react in various situations, is like a wonderful dream of ‘never leave the chair’ goodness.  This is immensely helpful and cost effective when compared to the amount of equipment historically required.

Nour Abu Sheik for Cisco Modeling Labs
Nour Abu Sheik for Cisco Modeling Labs

Watch the show: TechWiseTV 172 Cisco Modeling Labs

More information at their cisco.com/go/cml website.

Guest Expert: Nour Abu Sheik

Engineering Expert, Craig Brown, first introduced me to this software/service at Cisco Live Milan…but was stuck in Australia when we taped this…

Simulation vs. Emulation.  Different of course.  Emulation is a ‘pretender’ whereas ‘simulation’ is full on re-creation.  CML is a simulation of the environment that you create so your experience is as realistic as it can be.

Cisco Modeling Labs uses the same IOS code running on your hardware, but built to run in a simulated environment. Using OS images such as IOS, IOS XR, IOS XE, NX-OS, and L2 switching, you can design, build, visualize, and launch a network simulation in a matter of minutes rather than days.

Why do we care?

Well, as most of you know, (because we do talk about it a lot…) In the past few years a number of networking trends have emerged:

  • Cloud computing
  • Explosion of big data and analytics,
  • SDN (NFV as well while we are at it)
  • Internet of Things

What are the implications?

Designing, building, testing and launching physical networks can be an expensive, complex and time-consuming endeavor, and these trends are putting a premium on the need to speed up the process.

Even assuming you have access to all the gear, it can take days to build out a network before it can be tested, validated and deployed.  Doing this supports one of the most basic ‘best practices’ we all know we should be doing more of…but who has that kind of time?

How do we:

  • Test new OS versions and features
  • Stage new deployments
  • Troubleshoot problems

All within what is usually a less than ideal lab environment consisting of limited hardware, limited work space, scalability challenges with whatever can be scraped together, but we all still run into a lack of time, people and resources.

Accurately virtualizing the network offers huge benefits for

  • Architects who need to validate their designs
  • Operations teams that need to validate Production Ready
  • Network Engineering for running ‘what-if scenarios’, as well as to reproduce and test bugs, and prepare for network changes
  • Security teams validating DDOS scenarios, security breaches, and security impacts of network changes
  • Network Management teams wanting to confirm alerts are being capture or want to test changes and impacts

CML is a network simulation platform for both enterprise and SP teams.

“Software that can allow real world simulations in a virtual environment.”

Four phases to consider when we show this thing: Design, Build, Visualize and Simulate.


Show how easy it is to create from scratch. We start with a simple, ‘3 router’ network


  • Config builder template
  • Ease of building network configs and choice of template or manual or hybrid
  • Rapid build and easy access to resources for a single node of entire network. Show quick config changes and re-build


  • Protocol visualization
    • CML can visualize the entire network at the protocol level from one screen
    • Show change to node config and effect on OSPF areas
    • Quick troubleshooting, and what –if scenarios
    • Quick design, architecting confirmation of entire topology without going to each router
    • Troubleshooting

CML offers unique advantages for teams…especially when working in disparate physical locations.

  • Save different solution testing scenarios and share, all working on the same solution design/deployment
  • Architects, design, network and security teams all can review the same setup.

The IOS support is already quite robust: IOSv IOSv L2, IOS XRv, IOS XE…The same IOS that is built into the actual routers and switches, feature for feature.  This helps with new feature deployment, training and troubleshooting

You would be silly to not check this out.
You would be silly to not check this out.


Remember that a virtual environment will still differ in a few obvious ways.  CML supports the control plane of the IOS’s. Most network gear is differentiated by its hardware based interfaces.  This means that CML can give you a very accurate experience, but it is NOT an actual representation of any specific platform

Cisco Modeling Labs is sold as a subscription with full support, updates, upgrades and training materials.

Licensing is done per device and comes with expansion packs, nice bundled groupings to make it all easy.

Get more details at cisco.com/go/cml

You can also follow their twitter feed @ciscomodellabs

Let me know what you think.




Robb Boyd

Producer, Writer, Host