- Kube-proxy: Added dual-stack IPv4/IPv6 support to the iptables proxier. ([#82462](https://github.com/kubernetes/kubernetes/pull/82462), [@vllry](https://github.com/vllry)) [SIG Network]

- `-- 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.

### 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.

- The  performance of Pod affinity/anti-affinity in the scheduler has been improved. ([#67788](https://github.com/kubernetes/kubernetes/pull/67788), [@ahmad-diaa](https://github.com/ahmad-diaa)) Courtesy of SIG Scalability, and SIG Scheduling

([#62695](https://github.com/kubernetes/kubernetes/pull/62695), [@CaoShuFeng](https://github.com/CaoShuFeng))

pkg net/http, type CloseNotifier //deprecated
pkg net/http, type ProtocolError //deprecated
pkg net/http, type Request struct, Cancel //deprecated
pkg net/http, type Transport struct, Dial //deprecated
pkg net/http, type Transport struct, DialTLS //deprecated
pkg net/http, var ErrHeaderTooLong //deprecated
pkg net/http, var ErrMissingContentLength //deprecated
pkg net/http, var ErrShortBody //deprecated

pkg log/syslog (netbsd-arm64-cgo), const LOG_UUCP Priority
pkg log/syslog (netbsd-arm64-cgo), const LOG_WARNING = 4
pkg log/syslog (netbsd-arm64-cgo), const LOG_WARNING Priority
pkg log/syslog (netbsd-arm64-cgo), func Dial(string, string, Priority, string) (*Writer, error)
pkg log/syslog (netbsd-arm64-cgo), func NewLogger(Priority, int) (*log.Logger, error)
pkg log/syslog (netbsd-arm64-cgo), func New(Priority, string) (*Writer, error)

* etcd client add dial timeout. ([#61459](https://github.com/kubernetes/kubernetes/pull/61459), [@hzxuzhonghu](https://github.com/hzxuzhonghu))

### 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.
Since 1.21, Kubernetes clusters are enabled to support dual-stack networking by default.
In 1.23, the `IPv6DualStack` feature gate is removed.
The use of dual-stack networking is not mandatory.

  //
  // This field may hold a maximum of two entries (dual-stack families, in
  // either order).  These families must correspond to the values of the
  // clusterIPs field, if specified. Both clusterIPs and ipFamilies are
  // governed by the ipFamilyPolicy field.
  // +listType=atomic
  // +optional
  repeated string ipFamilies = 19;

  // IPFamilyPolicy represents the dual-stack-ness requested or required by