Before you begin
For information on selecting a messaging mode (unicast or multicast) for your cluster, see Communications in a Cluster.
If you are creating a cluster within an existing WebLogic Server environment or you need to ensure backward compatibility with older versions of WebLogic Server, you must use the multicast messaging type. IP multicast is a simple broadcast technology that enables multiple applications to subscribe to a given IP address and port number and listen for messages.
Enter the multicast address of the new cluster in Multicast Address. A multicast address is an IP address in the range from 126.96.36.199 to 188.8.131.52. The valid range is from 184.108.40.206 to 220.127.116.11. The default value used by WebLogic Server is 18.104.22.168. You should avoid using multicast addresses in the range x.0.0.1. This address must be unique to this cluster and should not be shared by other applications.
Enter the multicast port for the new cluster in Multicast Port. The multicast port is used by cluster members to communicate with each other. Valid values are between 1 and 65535.
The new cluster appears in the Summary of Clusters table.