IBM SG24-5131-00 User Manual

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IBM Certification Study Guide  AIX HACMP
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  
A point-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.