Cisco CML 2 - Install /Deploy


In this lesson, you will learn how to install and deploy Cisco Modeling Labs 2 on VMware ESXi, complete the initial setup, create your first lab, and understand how breakout connectivity works.

Cisco Modeling Labs provides a virtual environment for building, configuring, and testing network topologies without requiring physical routers and switches. This guide focuses specifically on an ESXi-based deployment.

Table of Contents

What Is Cisco Modeling Labs?

Cisco Modeling Labs, commonly called Cisco CML, is a network simulation and virtualization platform. It allows engineers, students, and architects to build virtual network topologies using Cisco and Linux-based node images.

CML can be used for configuration testing, troubleshooting practice, design validation, demonstrations, and technical training. Because the nodes operate as virtual machines, complex topologies can be created without requiring equivalent physical hardware.

ESXi Deployment Overview

In an ESXi deployment, Cisco CML runs as a virtual machine on a VMware ESXi host. The CML virtual machine provides the management interface, lab orchestration services, and the computing environment used to run virtual network nodes.

The general deployment process is:

  1. Prepare the VMware ESXi environment.
  2. Import or deploy the Cisco CML virtual appliance.
  3. Assign the required virtual hardware and network interfaces.
  4. Power on the CML virtual machine.
  5. Complete the initial system configuration.
  6. Open the CML web interface.
  7. Create and start a test lab.

Deployment Prerequisites

Before starting the deployment, confirm that the ESXi environment has sufficient compute, memory, storage, and networking resources for the CML virtual machine and the lab nodes you plan to run.

  • A supported VMware ESXi host
  • The Cisco CML deployment image or virtual appliance
  • Available CPU and memory resources
  • Sufficient datastore capacity
  • A management network with IP connectivity
  • DNS, default gateway, and NTP information when required
  • Administrative access to the ESXi host
  • A valid Cisco CML license

Resource requirements can vary by CML release and by the number and type of nodes used in each lab. Review the requirements for your specific CML version before deploying the appliance.

Installing Cisco CML on ESXi

Deploy the Cisco CML appliance through the VMware ESXi management interface. During deployment, select the appropriate datastore, virtual network, and virtual hardware settings.

  1. Log in to the VMware ESXi management interface.
  2. Start the virtual-machine deployment process.
  3. Select the Cisco CML deployment package.
  4. Choose the destination datastore.
  5. Connect the management interface to the correct virtual network.
  6. Review the assigned CPU, memory, and storage resources.
  7. Complete the deployment.
  8. Power on the Cisco CML virtual machine.

After powering on the appliance, monitor the virtual-machine console while the system initializes.

Initial CML Setup

During the initial setup, configure the management settings required to access the CML platform.

Typical settings include:

  • Management IP address
  • Subnet mask or prefix length
  • Default gateway
  • DNS servers
  • Hostname
  • Administrative credentials
  • Time and NTP settings

After completing the setup, open the CML management address in a supported web browser and sign in with the configured administrative account.

Creating Your First Lab

A CML lab is a virtual workspace containing nodes, links, interface connections, and optional configuration files.

  1. Log in to the Cisco CML web interface.
  2. Create a new lab.
  3. Assign a descriptive name to the lab.
  4. Add the required router, switch, firewall, server, or Linux nodes.
  5. Connect the node interfaces.
  6. Start the lab.
  7. Open each node console.
  8. Apply the required network configuration.
  9. Verify connectivity between the nodes.

Begin with a small topology so that management access, node startup, console connectivity, and interface communication can be verified before building a larger environment.

Understanding Breakout Connectivity

Breakout connectivity allows nodes inside a CML lab to communicate with networks or systems outside the internal CML topology.

Depending on the design, breakout connectivity can be used to reach:

  • The physical network connected to the ESXi host
  • Management systems outside the CML lab
  • Internet or upstream network services
  • External virtual machines
  • Other laboratory environments

When configuring breakout connectivity, verify the relationship between the CML external connector, the ESXi port group, VLAN configuration, upstream switching, IP addressing, and routing.

Incorrect VLAN assignments, missing routes, security policies, or mismatched virtual-network settings can prevent communication between CML nodes and external systems.

Video Demonstration

The following video demonstrates the Cisco CML 2 installation and deployment process on VMware ESXi, the creation of a basic lab, and the use of breakout connectivity.

Verifying the Deployment

After completing the installation, perform the following checks:

  1. Confirm that the CML virtual machine remains powered on.
  2. Verify that the management IP address responds from the administrator workstation.
  3. Open the CML web interface.
  4. Confirm that administrative login works.
  5. Create a small test lab.
  6. Start at least two nodes.
  7. Open the node consoles.
  8. Configure IP connectivity between the nodes.
  9. Verify that traffic passes across the virtual links.
  10. Test external connectivity when breakout networking is configured.

Basic Troubleshooting

CML Web Interface Is Not Reachable

  • Verify the management IP address and subnet mask.
  • Confirm the default gateway.
  • Check the ESXi port-group assignment.
  • Verify VLAN configuration on the virtual and physical network.
  • Confirm that the CML virtual machine is fully started.

Nodes Do Not Start

  • Check available CPU and memory resources.
  • Verify available datastore capacity.
  • Confirm that the required node image is available.
  • Review the node and system logs for startup errors.

Lab Nodes Cannot Reach External Networks

  • Verify the breakout or external connector configuration.
  • Check the ESXi virtual-switch and port-group settings.
  • Confirm the VLAN assignment.
  • Verify node IP addressing and default gateways.
  • Check upstream routing, NAT, and security policies.

Conclusion

Deploying Cisco Modeling Labs on VMware ESXi provides a flexible environment for creating virtual network topologies, practicing configuration, validating designs, and testing connectivity.

A successful deployment requires coordination between the CML appliance, ESXi virtual networking, IP addressing, available compute resources, and any external breakout connections.

After installation, always validate the platform with a small test lab before adding larger topologies or resource-intensive nodes.

Related Reading

About the Author

Ehsan Emad is a networking and cybersecurity expert with four CCIE certifications, a CCDE, CISSP, and extensive industry experience. He creates practical tutorials that turn complex networking technologies into clear, real-world solutions.