Question : weblogic clusters - multicast address

as part of the network setup for weblogic cluster, a multicast address should be assigned exclusively to the cluster. for the detailed requirement see
http://www.weblogic.com/docs/cluster/setup.html#676121.
anyone has any idea of how to do that ?
a detailed answer will be welcome.
* the machines in the cluster are sun solaris.

Answer : weblogic clusters - multicast address

Multicast is a feature which allows many machines on a single network to send and receive ona single IP address, meaning they can all here the same information.  This is use in Weblogic to allow the replication of JNDI directory info etc.

Okay, you need to first ask your network Administrator for a new unused Multicast IP address for your network, there is a defined range for this, it starts 224.....

After that, you set that up as stated in the Weblogic Clustering documents in the startup script of each server. I cannot remember the exact syntax but it is something like weblogic.cluster.multicast=224.xxx.xxx.xx

Now, you also have to get each of the IP addresses for each of your servers entered in your DNS (Again a task for your local Netowkr Admin dude) all under the one Name, this allows for round-robin access to your servers.

Hope this helped you.

-john.