4.2.4 About the Grid Naming Service (GNS) Virtual IP Address

The GNS virtual IP address is a static IP address configured in the Domain Name System (DNS).

The DNS delegates queries to the GNS virtual IP address, and the GNS daemon responds to incoming name resolution requests at that address. Within the subdomain, the GNS uses multicast Domain Name Service (mDNS), included with Oracle Clusterware, to enable the cluster to map host names and IP addresses dynamically as nodes are added and removed from the cluster, without requiring additional host configuration in the DNS.

To enable GNS, you must have your network administrator provide a set of IP addresses for a subdomain assigned to the cluster (for example, grid.example.com), and delegate DNS requests for that subdomain to the GNS virtual IP address for the cluster, which GNS serves. DHCP provides the set of IP addresses to the cluster. DHCP must be available on the public network for the cluster.