Requirements for private interfaces depend on whether you are using single or multiple Interfaces.
Network Requirements for Single Interface Private Network Clusters
Each node's private interface for interconnects must be on the same subnet.
The subnet must connect to every node of the cluster.
For example, if the private interfaces have a subnet mask of 255.255.255.0, then your private network is in the range 192.168.0.0--192.168.0.255, and your private addresses must be in the range of 192.168.0.[0-255]. If the private interfaces have a subnet mask of 255.255.0.0, then your private addresses can be in the range of 192.168.[0-255].[0-255]
Both IPv4 and IPv6 addresses are supported.
Network Requirements for Redundant Interconnect Usage Clusters
With Redundant Interconnect Usage, you can identify multiple interfaces to use for the cluster private network, without the need of using bonding or other technologies.
When you define multiple interfaces, Oracle Clusterware creates from one to four highly available IP (HAIP) addresses. Oracle RAC and Oracle Automatic Storage Management (Oracle ASM) instances use these interface addresses to ensure highly available, load-balanced interface communication between nodes. The installer enables Redundant Interconnect Usage to provide a high availability private network. By default, Oracle Grid Infrastructure software uses all of the HAIP addresses for private network communication, providing load-balancing across the set of interfaces you identify for the private network. If a private interconnect interface fails or become non-communicative, then Oracle Clusterware transparently moves the corresponding HAIP address to one of the remaining functional interfaces.
Each private interface should be on a different subnet.
Each cluster member node must have an interface on each private interconnect subnet, and these subnets must connect to every node of the cluster.
For example, you can have private networks on subnets 192.168.0 and 10.0.0, but each cluster member node must have an interface connected to the 192.168.0 and 10.0.0 subnets.
Endpoints of all designated interconnect interfaces must be completely reachable on the network. There should be no node that is not connected to every private network interface.
You can test if an interconnect interface is reachable using
You can use IPv4 and IPv6 addresses for the interfaces with Oracle Clusterware Redundant interconnects.
During installation, you can define up to four interfaces for the private network. The number of HAIP addresses created during installation is based on both physical and logical interfaces configured for the network adapter. After installation, you can define additional interfaces. If you define more than four interfaces as private network interfaces, then be aware that Oracle Clusterware activates only four of the interfaces at a time. However, if one of the four active interfaces fails, then Oracle Clusterware transitions the HAIP addresses configured to the failed interface to one of the reserve interfaces in the defined set of private interfaces.