`--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.

- Fixed the EndpointSliceController to correctly create endpoints for IPv6-only pods.
  
  Fixed the EndpointController to allow IPv6 headless services, if the IPv6DualStack
  feature gate is enabled, by specifying `ipFamily: IPv6` on the service. (This already

### **Network**

#### **IPv6**

*   [alpha] IPv6 support has been added. Notable IPv6 support details include:
    *   Support for IPv6-only Kubernetes cluster deployments. **<span style="text-decoration:underline;">Note:</span>** This feature does not provide dual-stack support.
    *   Support for IPv6 Kubernetes control and data planes.
    *   Support for Kubernetes IPv6 cluster deployments using kubeadm.

    * DualStack:
    * => IPv4 BackendPool name == clusterName
    * => IPv6 BackendPool name == <clusterName>-IPv6
    * This result into:
    * - clusters moving from IPv4 to duakstack will require no changes

- Fixed issue with Winkernel Proxier - IPV6 load balancer policies were missing when service was configured with `ipFamilyPolicy`: `RequireDualStack` ([#115503](https://github.com/kubernetes/kubernetes/pull/115503), [@princepereira](https://github.com/princepereira))

- Upgrade node local dns to 1.17.0 for better IPv6 support ([#99749](https://github.com/kubernetes/kubernetes/pull/99749), [@pacoxu](https://github.com/pacoxu)) [SIG Cloud Provider and Network]

### IPv4/IPv6 run

This final piece completes the work needed to comply with Level 1 of the [SLSA security framework](https://slsa.dev/) (Supply-chain Levels for Software Artifacts).

### IPv4/IPv6 Dual-stack Networking graduates to GA

[IPv4/IPv6 dual-stack networking](https://github.com/kubernetes/enhancements/tree/master/keps/sig-network/563-dual-stack) graduates to GA.

- When using IPV6-only, be sure to use `proxy-mode=iptables` as `proxy-mode=ipvs` is known to not work. ([#68437](https://github.com/kubernetes/kubernetes/issues/68437))

## Deprecations

- kube-apiserver

- Fixed a regression in `kube-proxy` where it might refuse to start if given
  single-stack `IPv6` configuration options on a node that has both `IPv4` and
  `IPv6` IPs. ([#121008](https://github.com/kubernetes/kubernetes/pull/121008), [@danwinship](https://github.com/danwinship))