Compaq ProLiant Clusters HA/F100 Administrator's Manual page 53

Designing the Compaq ProLiant Clusters HA/F100 and HA/F200 2-19
Example 2
The second example configuration consists of three single-port NICs (Figure
2-10). One NIC is dedicated to intracluster communication. The other two
NICs are used for cluster-to-LAN communication. The Compaq Advanced
Network Control Utility is used to configure two of the NICs—one as the
primary and one as the standby of a redundant pair.
The interconnect is fully redundant when the Microsoft clustering software is
configured to use the other network cards as backups for the interconnect.
Failure of the primary interconnect path results in intracluster communications
occurring over the primary NIC of the redundant pair. If the entire
interconnect card fails, the cluster nodes will still have a working
communication path.
The cluster-to-LAN communication is fully redundant up to the network hub.
With this configuration, even a failure of the primary NIC results only in the
transfer of the network path to the standby NIC. Other than a failure of the
network hub, any failure of any cluster network component will be resolved by
the redundancy of this configuration.
The primary disadvantage of this configuration as compared to Example 1 is
that an additional card slot is used by the third NIC.
Node 1
Backup Cluster to LAN and
Backup Interconnect Path
Figure 2-10. Use of three NICs to increase redundancy
Primary Interconnect Path
Primary Cluster to LAN and
Backup Interconnect Path
Hub
Clients
Node 2