Internal Kubernetes Deployment

After creating a Kubernetes cluster item using the Rancher UI, does the target server require an Internet connection to install Kubernetes and the Agent?

The internet connection in my work environment is unreliable (near air-gapped). In order to deploy a downstream Kubernetes cluster via Rancher as soon as possible, should I install and configure K3S as soon as I build the image via Elemental yaml? Will this result in an identity conflict when the various servers using the image register with the Rancher server?

Thank you and Sorry for my English.