VM Images for CML Labs
Each node in a simulated network topology in Cisco Modeling Labs runs as a virtual machine (VM). Your CML license provides you access to a variety of Cisco VM images and open source VM images to use with your labs in CML. We sometimes refer to these VM images as reference platforms. The refplat ISO file that you may use during initial CML installation provides one VM image for each of the default node types.
Attention: The Cisco VM images that are provided for download with Cisco Modeling Labs or as part of the CML refplat ISO file are only licensed for use within Cisco Modeling Labs. Downloading these VM images and using them outside Cisco Modeling Labs without a proper license is prohibited.
Cisco Reference Platform Images
CML does not emulate any specific hardware platform. CML runs special builds of Cisco's operating systems that are designed to run as virtual machines. Cisco has taken IOS, IOS-XR, and our other network operating systems, cut them off at the hardware abstraction layer, and ported them over so that they can run as a VM in a network simulation. For this reason, features of the Cisco OS implemented entirely in software generally work exactly as they would in a physical device that runs the same version of the corresponding operating system (IOS, IOS-XR, etc.). The software-based features include most of the control and management plane features of the OS. You should see the same behavior and the same bugs found on the corresponding version of OS that runs on a physical device. Cisco OS features that are executed on the hardware (ASIC) may not be supported unless Cisco has added a software-based implementation of the feature. The layer-2 switch image (IOSvL2) included in CML is an example where features that are normally implemented in the ASIC have been implemented in software for the VM image.
The Cisco reference platform images in CML are rate-limited, with no sense of a synchronized CPU clock across the nodes in a lab. CML uses virtualization, not emulation. Therefore, CML is very good for troubleshooting policy and configuration issues of supported features, but it's not generally suitable for testing throughput or timing.
Configurations taken directly from a physical Cisco device may not function as expected when applied to a Cisco node in a CML topology. Depending on feature sets configured in your production environment, you may be able to closely match your production topology and configuration, but some effort is normally required to adjust production configurations so that they can run in a CML lab.
See the page for a specific Cisco reference platform for more information about that node type:
- ASAv
- CAT 8000V
- CAT 9000v (beta VM image)
- CSR 1000v
- FMCv
- FTDv
- IOL
- IOL-L2
- IOSv
- IOSvL2
- IOS XRv 9000
- NX OS 9000
- Catalyst SD-WAN (including Manager, Controller, Validator, vEdge, and Cisco Edge)
The following Cisco reference platforms are deprecated. They are still available for download but are not included on the refplat ISO:
Non-Cisco VM Images
CML also provides some open source VM images and node types. These node types can be used for host nodes in your CML lab. Some of these VM images also include traffic generators and other tools that you can use to explore or troubleshoot your CML lab without the need for external connectivity.
Node Definition | Operating System | Description |
---|---|---|
Server | Tiny Core Linux | A lightweight host node type |
Alpine | Alpine Linux | A host node with additional tools for network troubleshooting and traffic generation |
Desktop | Alpine Linux | A host node with a graphical desktop via VNC |
Ubuntu | Ubuntu Linux | An Ubuntu Linux VM that supports cloud-init |
Trex | Alpine Linux | An Alpine Linux VM with the Trex traffic generator pre-installed |
WAN Emulator | Alpine Linux | An Alpine Linux VM with WanEM pre-installed |
Note: For all CML offerings other than CML-Free, the VMs for the third-party node types in the previous table do not count toward the total licensed node limit.
Adding Additional VM Images
The refplat ISO file provides one VM image for each of the default node types. The CML User Guide provides instructions for adding alternate versions of the Cisco operating systems and even third-party VM images to your CML instance:
The community of CML users has created and shared additional node definitions for use in CML. See the public cml-community repository to download additional node definitions or to share ones you have created.
The cml-community repository includes node definitions for Cisco VM images that are not bundled with CML but that may be available to you, depending on your or your company's entitlements. Examples of Cisco node definitions available from the cml-community repository are
- Cisco virtual wireless LAN controller (AireOS) (vWLC)
- Cisco Catalyst 9800 wireless LAN controller/switch (IOS-XE) (Catalyst 9800)
- Cisco SD-WAN (legacy location of the Cisco SD-WAN node definitions before CML 2.7)
Note: Cisco TAC provides support for creating custom node and image definitions, including guidance on how to use the UI and what the fields mean, but support for third-party VM images and content from the cml-community is supported on a best effort basis. CML product support does not include support for any Cisco or third-party VM images that are not bundled with the product. Unless otherwise noted in the cml-community pages, Cisco provides no guarantee that the node definitions in the cml-community repository will work with a particular version of the VM image or a particular version of CML itself.