A network interface can be stored as a global interface (as reported by the iflist command) or as a node-specific interface:
An interface is stored as a global interface when all of the nodes of an Oracle Real Application Clusters (Oracle RAC) cluster have the same interface connected to the same subnet. The global interface (and configuring all nodes with the same network interface for each public subnet and the same network interface for each private subnet) is not only the recommended configuration, but it is also the default installation configuration.
An interface can be stored as a node-specific (local) interface.
Note:
oracle现在还不支持不同节点使用不同的网段。建议rac节点配置public ip和private ip时使用对应的相同的网段。