master_cluster_public_hostname & openshift_master_cluster_hostname

[debianmaster]

openshift_master_cluster_public_hostname and openshift_master_cluster_hostname should always be set to different values.

openshift_master_cluster_public_hostname = the FQDN you use on your F5 VIP, that users will use to log in to the web UI etc.

openshift_master_cluster_hostname = the FQDN the nodes in the cluster use to communicate with the master. This is also added to all internally generated certificates within OpenShift and thus can be very different to what you are using for the public hostname