Assuming that like us, you spend the last 10 - 12 years deploying IPv6 and currently running servers on IPv6 only networks, the Kubernetes/Docker network stack is just plain broken. It can be done, but you need to start thinking about stuff like BGP.
Kubernetes should have been IPv6 only, with optional IPv4 ingress controllers.
It really feels like Kubernetes was developed by some enterprise Java developers. Nothing seems well defined, everything is done in the name of abstraction, but the rules of the abstraction are never clearly stated, only the purpose is.
I really hope someone takes the mantle of Leslie Lamport (creator of the language TLA - "the quixotic attempt to overcome engineers' antipathy towards mathematics") and replaces Kubernetes with some software with a first principles approach.
Kubernetes should have been IPv6 only, with optional IPv4 ingress controllers.