1. Proposed title of this feature request
Manually changing  the NodePort range, apart from 30000 to 32767  is possible.  

2. What is the nature and description of the request?
$ oc patch network.config.openshift.io cluster --type=merge -p '{ "spec":

}'
network.config.openshift.io/cluster patched

$ oc get network -o yaml cluster
apiVersion: config.openshift.io/v1
kind: Network
...
spec:
...
serviceNodePortRange: 29000-32768
The cluster should forbidden such configuration at first.
With the error message or warning message.

3. Why does the customer need this? (List the business requirements here)

• The node port range can be expanded bellow "29999" without error.

• The OCP cluster which expanded the node port range bellow "29999" is not supported.

• The node port range cannot be reverted after expanding it below "29999".

• If the cluster is expanded the node port range bellow "29999", it must be rebuild OCP cluster to revert to supported cluster.

4. List any affected packages or components.
NodePort service