So ive be running into issues some places like gns3vault have these old gns3 files that work with gns3 fine when importing, but I wanted to switch to CML so i worked with a LLM to create this prompt.

Side Note: my manual process was exporting a 1 node project from CML and giving it to chatgpt as reference then working with chatgpt to convert it over, we came up with the below prompt you can copy and paste into any llm and it should work theoretically.

Prompt: Convert GNS3 Lab to CML 2.5+ Compatible Format

I have a .gns3 project file and a set of startup-configs for each router. Please convert the lab to a fully working CML 2.5+ YAML file. Follow these steps exactly:

==—==

✅ Conversion Steps

1. Extract Device Info from .gns3 File

• Parse each node and its ports.
• Assign node_definition: iol-xe for routers.
• Use Ethernet0/x as the interface label format (not GigabitEthernet or FastEthernet).
• Position the nodes using their x, y coordinates from the file.

2. Fix Interface Labels

• For each node:
  • Update interface labels in the metadata to Ethernet0/0, Ethernet0/1, etc.
  • If the node only has 1 or 2 ports, don’t assign extra interfaces.

3. Update Router Configs

• Replace all instances of:
  • GigabitEthernet0/x
  • FastEthernet0/x
  • FastEthernet1/x
• With Ethernet0/x (and Ethernet0/x+1 if needed).
• Paste the cleaned configuration into each node’s configuration field.

4. Fix Links

• Rebuild links so they only reference existing interfaces (based on actual ports).
• Manually re-map connections if needed (e.g.:
  • Catch ↔ Mirror → Ethernet0/0 on both
  • Flash ↔ Mirror → Ethernet0/0 on Flash ↔ Ethernet0/1 on Mirror)

5. Final CML YAML Format

Include these top-level keys:

annotations: [] smart_annotations: [] nodes: [...] links: [...] lab: version: "0.3.0" description: "Converted from GNS3" notes: "Auto-converted"

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✅ Output

Return a .yaml file that can be directly imported into CML 2.5+ without any validation errors.