Chapter 6. Configure Public Key based SSH Authentication
From the first virtualization host, configure Public Key authentication based SSH for the root user to all three virtualization hosts.
Ensure that you use the hostnames or IP addresses associated with the back-end management network.
See the Red Hat Enterprise Linux 7 Installation Guide for more details: https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/System_Administrators_Guide/s1-ssh-configuration.html#s2-ssh-configuration-keypairs.