The figure shows two nodes, node 1 and node 2. Each node is running OC4J and has two NICs (network interface cards):
On node 1, NIC 1 is 123.45.67.11, and NIC 2 is 123.45.67.21.
On node 2, NIC 1 is 123.45.67.12, and NIC 2 is 123.45.67.22.
NIC 1 on each node is connected to the LAN.
NIC 2 on each node is connected to each other by private interconnect.