from v1beta3 and its management in the kube-system/kubeadm-config ConfigMap. This method of keeping track of what API endpoints exists in the cluster was replaced (in a prior release) by a method to annotate the etcd Pods that `kubeadm` creates in "stacked etcd" clusters. The following CLI sub-phases are deprecated and are now a NO-OP: for `kubeadm join`: "control-plane-join/update-status", for `kubeadm reset`: "update-cluster-status". Unless you are using these phases explicitly, you should not be...

- Kube-proxy: on dual-stack mode, if it is not able to get the IP Family of an endpoint, logs it with level InfoV(4) instead of Warning, avoiding flooding the logs for endpoints without addresses ([#88934](https://github.com/kubernetes/kubernetes/pull/88934), [@aojea](https://github.com/aojea)) [SIG Network]

- [IPv4/IPv6 dual-stack](https://kubernetes.io/docs/concepts/services-networking/dual-stack) enables the allocation of both IPv4 and IPv6 addresses to Pods and Services.

- Added support for projected volume in describe function  ([#70158](https://github.com/kubernetes/kubernetes/pull/70158), [@WanLinghao](https://github.com/WanLinghao))
- kubeadm now automatically creates a new stacked etcd member when joining a new control plane node (does not applies to external etcd) ([#69486](https://github.com/kubernetes/kubernetes/pull/69486), [@fabriziopandini](https://github.com/fabriziopandini))

- Users might specify the `kubectl.kubernetes.io/default-container` annotation in a Pod to...

## Changelog since v1.15.0

### Other notable changes

* kubeadm: implement support for concurrent add/remove of stacked etcd members ([#79677](https://github.com/kubernetes/kubernetes/pull/79677), [@neolit123](https://github.com/neolit123))

### IPv4/IPv6 run

IPv4/IPv6 dual-stack has been reimplemented for 1.20 to support dual-stack Services, based on user and community feedback. If your cluster has dual-stack enabled, you can create Services which can use IPv4, IPv6, or both, and you can change this setting for existing Services. Details are available in updated [IPv4/IPv6 dual-stack docs](https://docs.k8s.io/concepts/services-networking/dual-stack/), which cover the nuanced array of options.

* **[alpha]** New Bootstrap Token authentication and management method. Works well with kubeadm. kubeadm now supports managing tokens, including time based expiration, after...

- github.com/go-kit/kit: [v0.9.0](https://github.com/go-kit/kit/tree/v0.9.0)
- github.com/go-logfmt/logfmt: [v0.4.0](https://github.com/go-logfmt/logfmt/tree/v0.4.0)
- github.com/go-stack/stack: [v1.8.0](https://github.com/go-stack/stack/tree/v1.8.0)
- github.com/golang-jwt/jwt/v4: [v4.5.2](https://github.com/golang-jwt/jwt/tree/v4.5.2)
- github.com/golang/mock: [v1.1.1](https://github.com/golang/mock/tree/v1.1.1)

- `-- kube-controller-manager`
  `--node-cidr-mask-size-ipv4 int32`     Default: 24. Mask size for IPv4 node-cidr in dual-stack cluster.
`--node-cidr-mask-size-ipv6 int32`     Default: 64. Mask size for IPv6 node-cidr in dual-stack cluster.

    These 2 flags can be used only for dual-stack clusters. For non dual-stack clusters, continue to use  `--node-cidr-mask-size` flag to configure the mask size.