The below information is missing within OpenShift Container Platform 4.14 - Release Notes. Yet the same functionality/change is available in OpenShift Container Platform 4.14 and hence can trigger massive issues in case the customer is using 100.88.0.0/16 already. In OpenShift Container Platform 4.13 and earlier the CIDR is not mentioned in https://docs.openshift.com/container-platform/4.13/networking/cidr-range-definitions.html but starting with OpenShift Container Platform 4.14 it is. Yet customers won't go and check this page when upgrading, unless information are made available within the Release Notes.

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Open Virtual Network Infrastructure Controller default range
Previously, the IP address range 168.254.0.0/16 was the default IP address range that the Open Virtual Network Infrastructure Controller used for the transit switch subnet. With this update, the Controller uses 100.88.0.0/16 as the default IP address range. Do not use this IP range in your production infrastructure network. (https://issues.redhat.com/browse/OCPBUGS-20178)
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OpenShift Container Platform 4.14

Always

1. Check https://docs.openshift.com/container-platform/4.14/release_notes/ocp-4-14-release-notes.html, the above paragraph is missing

Customers already using "100.88.0.0/16" with OpenShift Container Platform 4.13 and below are not aware about this conflict coming in OpenShift Container Platform 4.14 and may hit serious issues when updating to OpenShift Container Platform 4.14.

The below paragraph must be added to the OpenShift Container Platform 4.14 - Release Notes immediately

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Open Virtual Network Infrastructure Controller default range
Previously, the IP address range 168.254.0.0/16 was the default IP address range that the Open Virtual Network Infrastructure Controller used for the transit switch subnet. With this update, the Controller uses 100.88.0.0/16 as the default IP address range. Do not use this IP range in your production infrastructure network. (https://issues.redhat.com/browse/OCPBUGS-20178)
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