During installation, you are asked to identify the planned use for each network adapter (or network interface) that Oracle Universal Installer (OUI) detects on your cluster node.
Each NIC can be configured to perform only one of the following roles:
Do Not Use
Network Interface Configuration Options
You must use the same private adapters for both Oracle Clusterware and Oracle RAC. The precise configuration you choose for your network depends on the size and use of the cluster you want to configure, and the level of availability you require. Network interfaces must be at least 1 GbE, with 10 GbE recommended. Alternatively, use InfiniBand for the interconnect.
If certified Network-attached Storage (NAS) is used for Oracle RAC and this storage is connected through Ethernet-based networks, then you must have a third network interface for NAS I/O. Failing to provide three separate interfaces in this case can cause performance and stability problems under load.
Redundant interconnect usage cannot protect network adapters used for public communication. If you require high availability or load balancing for public adapters, then use a third party solution. Typically, bonding, trunking or similar technologies can be used for this purpose.
You can enable redundant interconnect usage for the private network by selecting multiple network adapters to use as private adapters. Redundant interconnect usage creates a redundant interconnect when you identify more than one network adapter as private.