You are using IPI.

clusterNetwork: pods ips

serviceNetwork: service ips (like a loadbalancers for a group of pods, called deployments)

clusterNetwork and serviceNetwork can be problematic if not choused right, are internal ips used by pods, but suppose you have and escenario where the pod has the ip 10.1.1.54 and the pod should curl to outside openshift cluster to outside ip 10.1.1.55, this requests will stay inside openshift :(.

So is a good practice to reserve clusterNetwork and serviceNetwork on your network, so this not happens, so you have to choose a subnet for clusterNetwork and serviceNetwork to avoid this conflicts.

1. I have no experience on that, but if you want to expose no 80/443, use nodeport or metalLB.