Before starting the installation, you must have at least two interfaces configured on each node: One for the private IP address and one for the public IP address.
During installation, you are asked to identify the planned use for each network interface that Oracle Universal Installer (OUI) detects on your cluster node. Identify each interface as a public or private interface, or as an interface that you do not want Oracle Grid Infrastructure or Oracle ASM to use. Public and virtual internet protocol (VIP) addresses are configured on public interfaces. Private addresses are configured on private interfaces.
Configure IP addresses with one of the following options:
Dynamic IP address assignment using Multi-cluster or standard Oracle Grid Naming Service (GNS)
If you select this option, then network administrators delegate a subdomain to be resolved by GNS (standard or multicluster). Requirements for GNS are different depending on whether you choose to configure GNS with zone delegation (resolution of a domain delegated to GNS), or without zone delegation (a GNS virtual IP address without domain delegation).
For GNS with zone delegation:
For IPv4, a DHCP service running on the public network the cluster uses
For IPv6, an autoconfiguration service running on the public network the cluster uses
Enough addresses on the DHCP server to provide one IP address for each node, and three IP addresses for the cluster used by the Single Client Access Name (SCAN) for the cluster
Use an existing GNS configuration
Starting with Oracle Grid Infrastructure 12c Release 1 (12.1), a single GNS instance can be used by multiple clusters. To use GNS for multiple clusters, the DNS administrator must have delegated a zone for use by GNS. Also, there must be an instance of GNS started somewhere on the network and the GNS instance must be accessible (not blocked by a firewall). All of the node names registered with the GNS instance must be unique.
Static IP address assignment using DNS or host file resolution
If you select this option, then network administrators assign a fixed IP address for each physical host name in the cluster and for IPs for the Oracle Clusterware managed VIPs. In addition, either domain name server (DNS) based static name resolution is used for each node, or host files for both the clusters and clients have to be updated, resulting in limited SCAN functionality. Selecting this option requires that you request network administration updates when you modify the cluster.
For GNS without zone delegation, configure a GNS virtual IP address (VIP) for the cluster. To enable Oracle Flex Cluster, you must at least configure a GNS virtual IP address.