LSI MegaRAID SCSI 320-2 RAID Controller Series 518 Hardware Manual page 113

In production clustering scenarios, you need to use more than one
private network for cluster communication to avoid having a single point
of failure. Cluster Service can use private networks for cluster status
signals and cluster management. This provides more security than using
a public network for these roles. In addition, you can use a public network
for cluster management, or you can use a mixed network for both private
and public communications.
In any case, verify that at least two networks are used for cluster
communication; using a single network for node-to-node communication
creates a potential single point of failure. We recommend that you use
multiple networks, with at least one network configured as a private link
between nodes and other connections through a public network. If you
use more than one private network, make sure that each uses a different
subnet, as Cluster Service recognizes only one network interface per
subnet.
This document assumes that only two networks are in use. It describes
how you can configure these networks as one mixed and one private
network.
Cluster Installation 7-19
Copyright © 2002 by LSI Logic Corporation. All rights reserved.