Repeatable Lab Network Environment

Flint International excels in the art of creating engaging and highly effective learning experiences, setting the standard in the IT industry. Our team of experienced instructors and engineers excels in creating technology-focused content, including interactive labs. Our goal is to engage learners effectively while delivering essential IT knowledge. With a deep understanding of both pedagogy and cutting-edge technology, Flint International is the go-to partner for companies and individuals seeking an innovative and results-driven approach to IT training.

One of our recent assignments was to develop a training programme that featured interactive labs for students. The training focused on network design, implementation, and troubleshooting, requiring an environment that closely resembled real-world enterprise network situations. The challenge lay in creating a lab environment where a substantial number of students could simultaneously utilize the “same network architecture” without stepping on each other’s toes.


  1. Ensure that all students work independently in a unified environment without causing disruptions to another’s workspace.
  2. The infrastructure had to accommodate the varying number of students while ensuring that deploying such environments could be done efficiently and repeatably.


To address these challenges, we employed a solution that involves the nested ESXi approach. This entails running an ESXi hypervisor instance as a virtual machine on the ESXi hypervisor, which, in turn, operates on the physical hardware. The mechanism resembles the structure presented in the Inception movie – it is a hosting environment within a hosting environment.

Part 1: The Nested ESXi Template

A master copy of the network environment using nested ESXi was created. This includes network devices like routers, and virtual machines like servers or clients interconnected between each other and completely independent of the hosting environment. The master copy serves as the foundation and can be edited, ensuring it remains up-to-date with content and technology updates.

Part 2: Connectivity and Accessibility

Each nested ESXi instance had its own layer 2 connectivity to a centralized network router, where each of those layer 2 domains had a layer 3 interface in a separate VRF (routing instance). VRF leaking was enabled to facilitate external connectivity to and from the separate nested ESXi instances.

A web jump server was established, allowing students global access to the lab environment via a browser. This also went hand in hand with remote learning, which is especially beneficial in today’s distributed workforce environments.

Part 3: Cloning and Scalability with Automation

Ansible and script servers were set up to streamline the creation and deletion of nested ESXi student instances as well as generate credentials to access the web jump server. This made the provision of lab environments for five of fifty students as simple as clicking a button, avoiding lengthy setup times.


  1. Autonomous Learning: Students had the freedom to experiment and learn without the fear of disrupting others, enhancing the learning experience.
  2. Flexibility: With a scalable solution, our training modules could cater to a variable number of students with ease.
  3. Accessibility: Remote access meant that learning wasn’t confined to a physical space. Students could access labs from anywhere, promoting a continuous learning culture.
  4. Efficiency: Automation reduced the overhead of manual setups, ensuring resources were optimized, and students spent more time learning than setting up environments.

In summary, our in-house repeatable lab network environment initiative transformed our training processes. The concept of using Nested ESXi provided the backbone, while automation and strategic design principles ensured scalability, repeatability, and a stellar learning experience.

At Flint, we look forward to using our expertise and resources to help you reach such a decision and successfully achieve your training goals.

Get in touch, we are looking forward to hearing from you!

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