A previous release built hyperkube using the debian-hyperkube-base@v1.0.0,
    which was updated to address a CVE in the CNI plugins.
    
    A side-effect of using this new image was that the networking packages
    (namely `iptables`) drifted from the versions used in the kube-proxy images.
  
    The following issues were filed on kube-proxy failures when using hyperkube:

- kubeadm now works better when not connected to the Internet. In addition,  common kubeadm commands will now work without an available networking interface. ([#67397](https://github.com/kubernetes/kubernetes/pull/67397), [@neolit123](https://github.com/neolit123))

- Fixed the sample-apiserver so that its BanFlunder admission plugin can be used. ([#68417](https://github.com/kubernetes/kubernetes/pull/68417), [@MikeSpreitzer](https://github.com/MikeSpreitzer))
- APIService availability related to networking glitches are corrected faster ([#68678](https://github.com/kubernetes/kubernetes/pull/68678), [@deads2k](https://github.com/deads2k))

  
    A previous release built hyperkube using the debian-hyperkube-base@v1.0.0,
    which was updated to address a CVE in the CNI plugins.
    
    A side-effect of using this new image was that the networking packages
    (namely `iptables`) drifted from the versions used in the kube-proxy images.
  
    The following issues were filed on kube-proxy failures when using hyperkube:

  to GA. Services that do not have the field configured will continue to operate
  with their existing behavior. Refer to the documentation
  https://kubernetes.io/docs/concepts/services-networking/service/#traffic-distribution
  for more details. ([#130673](https://github.com/kubernetes/kubernetes/pull/130673), [@gauravkghildiyal](https://github.com/gauravkghildiyal)) [SIG Apps, Network and Testing]

  - NetworkPolicy resources will no longer be served from `extensions/v1beta1` in v1.16. Migrate use to the `networking.k8s.io/v1` API, available since v1.8. Existing persisted data can be retrieved via the `networking.k8s.io/v1` API.

### Feature

- Kubelet TCP and HTTP probes are more effective using networking resources: conntrack entries, sockets, ... 

- Removed the networking `alpha` API `ClusterCIDR`. ([#121229](https://github.com/kubernetes/kubernetes/pull/121229), [@aojea](https://github.com/aojea))

### API Change

delivered incremental improvements to node reliability.

[SIG Node]: https://github.com/kubernetes/community/tree/master/sig-node

### SIG Network

[SIG Network][] is responsible for networking components, APIs, and plugins in Kubernetes.

For the 1.8 release, SIG Network enhanced the NetworkPolicy API to support pod egress traffic policies.

- `Ingress` and `IngressClass` resources have graduated to `networking.k8s.io/v1`. Ingress and IngressClass types in the `extensions/v1beta1` and `networking.k8s.io/v1beta1` API versions are deprecated and will no longer be served in 1.22+. Persisted objects can be accessed via the `networking.k8s.io/v1` API. Notable changes in v1 Ingress objects (v1beta1 field names are unchanged):