- Add --permit-address-sharing flag to `kube-apiserver` to listen with `SO_REUSEADDR`. While allowing to listen on wildcard IPs like 0.0.0.0 and specific IPs in parallel, it avoids waiting for the kernel to release socket in `TIME_WAIT` state, and hence, considerably reducing `kube-apiserver` restart times under certain conditions. ([#93861](https://github.com/kubernetes/kubernetes/pull/93861),...

* Fixed bug in AWS provider to handle multiple IPs when using more than 1 network interface per ec2 instance. ([#50112](https://github.com/kubernetes/kubernetes/pull/50112), [@jlz27](https://github.com/jlz27))

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### Storage

  2. If you were previously overriding the kube-proxy configuration for performance reasons, this may no longer be necessary. See https://kubernetes.io/docs/reference/networking/virtual-ips/#optimizing-iptables-mode-performance. ([#115138](https://github.com/kubernetes/kubernetes/pull/115138), [@danwinship](https://github.com/danwinship))

* Fixed bug in AWS provider to handle multiple IPs when using more than 1 network interface per ec2 instance. ([#50112](https://github.com/kubernetes/kubernetes/pull/50112), [@jlz27](https://github.com/jlz27))

- 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]

### SIG Azure

- Ensured orphan public IPs on Azure deleted when service recreated with the same name. ([#70463](https://github.com/kubernetes/kubernetes/pull/70463), [@feiskyer](https://github.com/feiskyer))

- Resolves an issue that causes winkernel proxier to treat stale VIPs as valid ([#113558](https://github.com/kubernetes/kubernetes/pull/113558), [@daschott](https://github.com/daschott)) [SIG Network and Windows]

- Added an e2e test to verify that the cluster is not vulnerable to CVE-2021-29923 when using Services with IPs with leading zeros, note that this test is a necessary but not sufficient condition, all the components in the clusters that consume IPs addresses from the APIs MUST interpret them as decimal or discard them. ([#107552](https://github.com/kubernetes/kubernetes/pull/107552), [@aojea](https://github.com/aojea))