Dual Network
A dual-network setup has two separate networks for communication. Nodes are connected to two networks, and each node has two service adapters available to clients. If one network fails, the remaining network can still function, connecting nodes and providing resource access to clients.
In some recovery situations, a node connected to two networks may route network packets from one network to another. In normal cluster activity, however, each network is separate—both logically and physically.
Keep in mind that a client, unless it is connected to more than one network, is susceptible to network failure.
The following figure shows a dual-network setup:
Figure 6. Dual-Network Setup
Point-to-Point Connection
Apoint-to-point connection links two (neighboring) cluster nodes directly. SOCC, SLIP, and ATM are point-to-point connection types. In HACMP clusters of four or more nodes, however, use an SOCC line only as a private network between neighboring nodes because it cannot guarantee cluster communications with nodes other than its neighbors.
36 IBM Certification Study Guide AIX HACMP
