ansible-role-k3s/documentation/configuration/ipv4-ipv6-dual-stack.md

IPv4 and IPv6 Dual-stack config

If you need to run your K3S cluster with both IPv4 and IPv6 address ranges you will need to configure the k3s_server.cluster-cidr and k3s_server.service-cidr values specifying both ranges.

✋ if you are using k3s<1.23 you will need to use a different CNI as dual-stack support is not available in Flannel.

Below is a noddy example:

---

k3s_server:
  # Using Calico on k3s<1.23 so Flannel needs to be disabled.
  flannel-backend: 'none'
  # Format: ipv4/cidr,ipv6/cidr
  cluster-cidr: 10.42.0.0/16,fc00:a0::/64
  service-cidr: 10.43.0.0/16,fc00:a1::/64