- `-- 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.

  1. When configuring a dual-stack cluster, the user must specify both `--node-cidr-mask-size-ipv4` and `--node-cidr-mask-size-ipv6` to set the per-node IP mask sizes, instead of the previous `--node-cidr-mask-size` flag.
  2. The `--node-cidr-mask-size` flag is mutually exclusive with `--node-cidr-mask-size-ipv4` and `--node-cidr-mask-size-ipv6`.

    * kube-controller-manager: convert service CIDR to list `--service-cluster-ip-range=<CIDR>,<CIDR>` and make sure `IPv6DualStack` feature flag is turned on. The flag is validated as above.
    * + to use:

**Action required** for Kubernetes cluster administrators and for distributions that manage the cluster Service CIDR.
Kubernetes now allows users to define the cluster Service CIDR via an API object: ServiceCIDR.

- Kubeadm now supports automatic calculations of dual-stack node cidr masks to kube-controller-manager. ([#85609](https://github.com/kubernetes/kubernetes/pull/85609), [@Arvinderpal](https://github.com/Arvinderpal)) [SIG Cluster Lifecycle]

- Kube-controller-manager: volume plugins can be restricted from contacting local and loopback addresses by setting `--volume-host-allow-local-loopback=false`, or from contacting specific CIDR ranges by setting `--volume-host-cidr-denylist` (for example, `--volume-host-cidr-denylist=127.0.0.1/28,feed::/16`) ([#91785](https://github.com/kubernetes/kubernetes/pull/91785), [@mattcary](https://github.com/mattcary)) [SIG API Machinery, Apps, Auth, CLI, Network, Node, Storage and Testing]...

* Fix overlay2 container disk metrics for Docker and CRI-O ([#54827](https://github.com/kubernetes/kubernetes/pull/54827), [@dashpole](https://github.com/dashpole))
* API machinery's httpstream/spdy calls now support CIDR notation for NO_PROXY ([#54413](https://github.com/kubernetes/kubernetes/pull/54413), [@kad](https://github.com/kad))

    * - Don't generate empty record for externalName service.
    * - Add validation for upstreamNameserver port.
    * - Update go version to 1.9.3.
* Backport Cloud CIDR allocator fixes to 1.9 ([#61797](https://github.com/kubernetes/kubernetes/pull/61797), [@satyasm](https://github.com/satyasm))

- KEP-1880: Users of the new feature to add multiple service CIDR will use by default a dual-write strategy on the new ClusterIP allocators to avoid the problem of possible duplicate IPs allocated to Services when running skewed kube-apiservers using different allocators. They can opt-out of this behavior by enabled...

  * Add ip-masq-agent addon to the addons folder which is used in GCE if `--non-masquerade-cidr` is set to 0/0 ([#46038](https://github.com/kubernetes/kubernetes/pull/46038), [@dnardo](https://github.com/dnardo))