OpenShift Container Platform 4 UPI: DNS Prerequisites before installation example.

Issue

While selecting the base domain to deploy the cluster to, all DNS records will be sub-domains of this base and will also include the cluster name. The base domain is used to create routes to your OpenShift Container Platform cluster components. The full DNS name for your cluster is a combination of the baseDomain and metadata.name parameter values that uses the <metadata.name>. format. A fully-qualified domain or subdomain name, such as example.com.

By default, when installing OpenShift using the full-stack automation method on supported cloud providers, the OpenShift installer automatically performs the DNS service configuration.

Administrators must configure the DNS service when installing OpenShift using the full-stack automation method on the following infrastructures:

Red Hat OpenStack Platform cloud provider using an external DNS
VMware vSphere
Bare metal