SIG Network is moving IPv6 to Beta in Kubernetes 1.18, after incrementing significantly the test coverage with new CI jobs.

NodeLocal DNSCache is an add-on that runs a dnsCache pod as a daemonset to improve clusterDNS performance and reliability. The feature has been in Alpha since 1.13 release. The SIG Network is announcing the GA graduation of Node Local DNSCache [#1351](https://github.com/kubernetes/enhancements/pull/1351)

## Known Issues

`system:aggregate-to-edit` role no longer includes write access to the Endpoints API. For new Kubernetes 1.22 clusters, the `edit` and `admin` roles will no longer include that access in newly created Kubernetes 1.22 clusters. This will have no affect on existing clusters upgrading to Kubernetes 1.22. To retain write access to Endpoints in the aggregated `edit` and `admin` roles for newly created 1.22 clusters, refer to https://github.com/kubernetes/website/pull/29025. ([#103704](https://github.com/kubernet...

* Validate deletion timestamp doesn't change on update ([#24839](https://github.com/kubernetes/kubernetes/pull/24839), [@liggitt](https://github.com/liggitt))
* Add support for running clusters on GCI ([#24893](https://github.com/kubernetes/kubernetes/pull/24893), [@andyzheng0831](https://github.com/andyzheng0831))

* Support autoprobing node-security-group for openstack cloud provider, Support multiple Security Groups for cluster's nodes. ([#50836](https://github.com/kubernetes/kubernetes/pull/50836), [@FengyunPan](https://github.com/FengyunPan))

        @Test
        @DisplayName("Should handle typical Windows NTFS configuration")
        void shouldHandleTypicalNTFSConfiguration() throws SMBProtocolDecodingException {
            // Given - typical NTFS: 4KB clusters (8 sectors * 512 bytes)
            long totalClusters = 26214400L; // 100GB / 4KB
            long freeClusters = 13107200L; // 50GB / 4KB

            ByteBuffer buffer = ByteBuffer.allocate(32);

* Retry 'connection refused' errors when setting up clusters on GCE. ([#57394](https://github.com/kubernetes/kubernetes/pull/57394), [@mborsz](https://github.com/mborsz))
* Retry 'connection refused' errors when setting up clusters on GCE. ([#57394](https://github.com/kubernetes/kubernetes/pull/57394), [@mborsz](https://github.com/mborsz))

- Upgrades `IPv6Dualstack` to `Beta` and turns it on by default. New clusters or existing clusters are not be affected until an actor starts adding secondary Pods and service CIDRS CLI flags as described here: [IPv4/IPv6 Dual-stack](https://github.com/kubernetes/enhancements/tree/master/keps/sig-network/563-dual-stack) ([#98969](htt...

`--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.

* Scheduling conformance tests related to daemonsets should set the annotation that relaxes node selection restrictions, if any are set. This ensures conformance tests can run on a wider array of clusters. ([#68793](https://github.com/kubernetes/kubernetes/pull/68793), [@aveshagarwal](https://github.com/aveshagarwal))

- Multiple Kubernetes clusters can now share the same resource group
    - When upgrading from previous releases, issues will arise with public IPs if multiple clusters share the same resource group. To solve these problems, make the following changes to the cluster: