While in https://docs.redhat.com/en/documentation/openshift_container_platform/4.18/html-single/networking/index#cidr-range-definitions the default required and reserved CIDRs are defined, it was found that with Hosted Control-Planes additional CIDRs are being used/reserved to avoid conflicts. Unfortunately those additional CIDRs are not captured in https://docs.redhat.com/en/documentation/openshift_container_platform/4.18/html-single/networking/index#cidr-range-definitions or the Hosted Control-Plane documentation, causing customers to hit undesired effects when using Hosted Control-Planes.

That is the reason why we are asking to have the additional required CIDRs for Hosted Control-Planes added to https://docs.redhat.com/en/documentation/openshift_container_platform/4.18/html-single/networking/index#cidr-range-definitions to make sure they are being reserved and considered when installing Hosted Control-Planes.

- v4InternalSubnet: 100.65.0.0/16 (OVN-Kubernetes)
- clusterNetwork: 10.132.0.0/14 (pod network)
- serviceNetwork: 172.31.0.0/16 

OpenShift Container Platform 4.16 and later with Hosted Control-Plane    

Always

1. Install OpenShift Container Platform 4 with Hosted Control-Plane
2. Using 100.65.0.0/16 for the clusterNetwork of the Hosted Cluster
    

The system is complaining that 100.65.0.0/16 can not be used, because it is a reserved CIDR. Still the CIDR and also clusterNetwork and serviceNetwork for Hosted Control-Plane is not documented and therefore not obvious to customers that this can be used.

To have the additional CIDR reserved for/by Hosted Control-Plane documented in https://docs.redhat.com/en/documentation/openshift_container_platform/4.18/html-single/networking/index#cidr-range-definitions or some part of Hosted Control-Plane documentation to make it obvious that those ranges are being reserved/used and hence would need to be considered when installing Hosted Control-Plane.