VCA managers communicate with other processes on the same or other nodes via UDP multi-cast.
On the same node. UDP multi-cast allows sending messages to all members in a multi-cast
group simultaneously, expecting no answer that the message received.
1. Check if multi-cast is enabled on the interface to be used, run from a shell e.g. ifconfig eth0.
It should show multi-cast enabled.
2. If two nodes are attached to a switch – the switch has to support it.
On a managed switch igmp has to be enabled. This usually requires help from IT staff.
3. The cluster manager needs to know on what interface to send the multi-cast network packets.