To implement GNS, your network administrator must configure the DNS to set up a domain for the cluster, and delegate resolution of that domain to the GNS VIP.

The subdomain name, can be any supported DNS name such as sales-cluster.rac.com. You can use a separate domain, or you can create a subdomain of an existing domain for the cluster.

Oracle recommends that the subdomain name be distinct from your corporate domain. For example, if your corporate domain is mycorp.example.com, the subdomain for GNS might be rac-gns.com.

If the subdomain is not distinct, then it should be for the exclusive use of GNS. For example, if you delegate the subdomain mydomain.example.com to GNS, then there should be no other domains that share it such as lab1.mydomain.example.com.