Here’s a complete checklist that covers every step required to ensure your labs are fully compatible with the latest CML version. (issue i ran into while doing ENARSI (300-410) v1.1 Video Training Series (2023 Blueprint) on Udemy)

You can also copy and paste these steps into any LLM and ask it to fix it for you(also keep in mind i was using the free version of CML)

This guide ensures all metadata, node definitions, and interface names are updated properly.

---

🧱 1. Top-Level YAML Structure

Make sure your .yaml lab files include these required top-level keys:

annotations: []
smart_annotations: []
nodes: [...]
links: [...]
lab:
  version: "0.3.0"
  description: Your lab description here
  notes: Any notes you want to include

✅ Tip: lab.version: "0.3.0" is mandatory for compatibility with CML 2.5+.

---

⚙️ 2. Node Definition Updates

Replace any use of the older iosv node definition with iol-xe.
Find and replace:

node_definition: iosv

with:

node_definition: iol-xe

---

🔌 3. Fix Interface Labels (YAML Metadata)

In the interface metadata (under each node), update labels from GigabitEthernet0/x to the proper format:

Ethernet0/x

📌 For example:

interface: i0
label: Ethernet0/0

---

🛠️ 4. Fix Interface Names (Router Configs)

Inside each router’s config section (in the configuration: block), make sure you’re using Ethernet0/x, not GigabitEthernet0/x.

✅ Example fix:

interface Ethernet0/0
 ip address 10.0.0.1 255.255.255.0

---

🧽 5. Cleanup Lab Metadata

Make sure your lab file doesn’t include unsupported keys (such as author). Your final lab metadata should look like this:

lab:
  version: "0.3.0"
  description: ...
  notes: ...

---

✅ Final Output Checklist

Before importing your YAML file into CML 2.5+, confirm the following:

✅ Top-level keys include annotations, smart_annotations, nodes, links, and lab

✅ lab.version is "0.3.0"

✅ node_definition is iol-xe

✅ All interface labels are Ethernet0/x

✅ All router configs use Ethernet0/x