To use your multicast configuration for data groups, when you create a data group in the Enterprise Manager, you must select the Multicast option. For more information about how to create a data group, see Creating Data Groups. If you create your data groups programmatically, when you call nSession.createDataGroup, you must pass an additional boolean that marks the data group as multicast-enabled.

To use your multicast configuration for inter-realm communication in a cluster, you must set the Use for Clusters option on each cluster realm that has multicast configured. The multicast address can be the same for all realms, or you can choose a different multicast address for each realm. With this feature enabled, each realm will know the multicast address for each of the other realms in the cluster and will listen on these addresses for inter-realm cluster communication.