HADB uses UDP multicast and thus you must enable multicast on your system’s routers and host network interface cards. If HADB spans multiple sub-networks, you must also enable multicast on the routers between the sub-networks. For best results, put HADB nodes all on same network. Application server instances may be on a different sub network.
The following suggestions will enable HADB to work optimally in the network:
Use switched routers so that each network interface has a dedicated 100 Mbps or better Ethernet channel.
When running HADB on a multi-CPU machine hosting four or more HADB nodes, use 1 Gbps Ethernet cards. If the average session size is greater than 50 KB, use 1 Gbps Ethernet cards even if there are less than four HADB nodes per machine.
If you suspect network bottlenecks within HADB nodes:
Run network monitoring software on your HADB servers to diagnose the problem.
Consider replacing any 100 Mbps Ethernet cards in the network with 1 Gbps Ethernet cards.