- `-- 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.

- 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]

- 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)) [SIG Network]

* Fix panic in kubectl cp command ([#75037](https://github.com/kubernetes/kubernetes/pull/75037), [@soltysh](https://github.com/soltysh))
* Fix kubelet start failure issue on Azure Stack due to InstanceMetadata setting ([#74936](https://github.com/kubernetes/kubernetes/pull/74936), [@rjaini](https://github.com/rjaini))

- The `CloudDualStackNodeIPs` feature is now `beta`, meaning that when using
  an external cloud provider that has been updated to support the feature,
  you can pass comma-separated dual-stack `--node-ips` to `kubelet` and have
  the cloud provider take both IPs into account. ([#120275](https://github.com/kubernetes/kubernetes/pull/120275), [@danwinship](https://github.com/danwinship))

- Graduated HorizontalPodAutoscaler support for per-container metrics to stable. ([#123482](https://github.com/kubernetes/kubernetes/pull/123482), [@sanposhiho](https://github.com/sanposhiho))

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

    * future, client-side validation in 1.14 kubectl against a 1.15 cluster will reject
    * unknown fields for CRDs with validation schema defined. 
* Fix kubelet start failure issue on Azure Stack due to InstanceMetadata setting ([#74936](https://github.com/kubernetes/kubernetes/pull/74936), [@rjaini](https://github.com/rjaini))

* no ([#75820](https://github.com/kubernetes/kubernetes/pull/75820), [@YoubingLi](https://github.com/YoubingLi))
* Use stdlib to log stack trace when a panic occurs ([#75853](https://github.com/kubernetes/kubernetes/pull/75853), [@roycaihw](https://github.com/roycaihw))

* Increase allowed lag for ssh key sync loop in tunneler to allow for one failure ([#60068](https://github.com/kubernetes/kubernetes/pull/60068), [@wojtek-t](https://github.com/wojtek-t))
* Fixing a bug in OpenStack cloud provider, where dual stack deployments (IPv4 and IPv6) did not work well when using kubenet as the network plugin. ([#59749](https://github.com/kubernetes/kubernetes/pull/59749), [@zioproto](https://github.com/zioproto))