Dual-stack Networking

Note: Dual stack networking setup requires that you configure Calico or a custom CNI as the CNI provider.

Use the following k0s.yaml as a template to enable dual-stack networking. This configuration will set up bundled calico CNI, enable feature gates for the Kubernetes components, and set up kubernetes-controller-manager.

spec:
  network:
    podCIDR: "10.244.0.0/16"
    serviceCIDR: "10.96.0.0/12"
    provider: calico
    calico:
      mode: "bird"
    dualStack:
      enabled: true
      IPv6podCIDR: "fd00::/108"
      IPv6serviceCIDR: "fd01::/108"

CNI Settings: Calico

For cross-pod connectivity, use BIRD for the backend. Calico does not support tunneling for the IPv6, and thus VXLAN and IPIP backends do not work.

Note: In any Calico mode other than cross-pod, the pods can only reach pods on the same node.

CNI Settings: External CNI

Although the k0s.yaml dualStack section enables all of the neccessary feature gates for the Kubernetes components, for use with an external CNI it must be set up to support IPv6.

Additional Resources

• https://kubernetes.io/docs/concepts/services-networking/dual-stack/
• https://kubernetes.io/docs/tasks/network/validate-dual-stack/
• https://www.projectcalico.org/dual-stack-operation-with-calico-on-kubernetes/
• https://docs.projectcalico.org/networking/ipv6