// as the clusterIP.
  // "ExternalName" aliases this service to the specified externalName.
  // Several other fields do not apply to ExternalName services.
  // More info: https://kubernetes.io/docs/concepts/services-networking/service/#publishing-services-service-types
  // +optional
  optional string type = 4;

  // externalIPs is a list of IP addresses for which nodes in the cluster

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.

* Cluster federation servers have changed the location in etcd where federated services are stored, so existing federated services must be deleted and recreated. Before upgrading, export all federated services from the federation server and delete the services. After upgrading the cluster, recreate the federated services from the exported data. ([#37770](https://github.com/kubernetes/kubernetes/pull/37770), [@enj](https://github.com/enj))

### Avoiding Collisions in IP allocation to Services

Kubernetes 1.24 introduced a new opt-in feature that allows you to
[soft-reserve a range for static IP address assignments](https://kubernetes.io/docs/concepts/services-networking/service/#service-ip-static-sub-range)
to Services.
With the manual enablement of this feature, the cluster will prefer automatic assignment from

* Properly manage security groups for loadbalancer services on OpenStack. ([#65373](https://github.com/kubernetes/kubernetes/pull/65373), [@multi-io](https://github.com/multi-io))

## Changelog since v1.12.7

### Other notable changes

* Connections from Pods to Services with 0 endpoints will now ICMP reject immediately, rather than blackhole and timeout. ([#72534](https://github.com/kubernetes/kubernetes/pull/72534), [@thockin](https://github.com/thockin))

* Fix a scalability issue where high rates of event writes degraded etcd performance. ([#64539](https://github.com/kubernetes/kubernetes/pull/64539), [@ccding](https://github.com/ccding))
* Properly manage security groups for loadbalancer services on OpenStack. ([#65373](https://github.com/kubernetes/kubernetes/pull/65373), [@multi-io](https://github.com/multi-io))

- The conformance tests:
  - Services should serve multiport endpoints from pods
  - Services should serve a basic endpoint from pods
  were only validating the API objects, not performing any validation on the actual Services implementation.

* Ensure Azure load balancer cleaned up on 404 or 403 when deleting LoadBalancer services. ([#75256](https://github.com/kubernetes/kubernetes/pull/75256), [@feiskyer](https://github.com/feiskyer))

- Added CEL expressions to `v1alpha1 AuthenticationConfiguration`. ([#121078](https://github.com/kubernetes/kubernetes/pull/121078), [@aramase](https://github.com/aramase))
- Added Windows support for InPlace Pod Vertical Scaling feature. ([#112599](https://github.com/kubernetes/kubernetes/pull/112599), [@fabi200123](https://github.com/fabi200123)) [SIG Autoscaling, Node, Scalability, Scheduling and Windows]