Using Serviceguard Extension for RAC, 9th Edition, September 2010

CLUSTER_INTERCONNECT_SUBNET can be used to recover from Oracle cluster communications
network failures in certain configurations.
Single Network for Cluster Communications
The single network configuration is the most common configuration for network installations.
In this configuration, there is sufficient bandwidth for all cluster communications traffic to go
through one network. If there are multiple databases, all database traffic goes through the same
network.
As shown in Figure 2-1, both CSS-HB and SG-HB are on the same network. The primary and
standby interface pair protects against a single network interface failure. Serviceguard monitors
the network and will perform a local LAN failover (transparent to CSS and RAC) if the primary
interface fails.
NOTE: A package with the CLUSTER_INTERCONNECT_SUBNET parameter is available for both
Modular and Legacy packages. A package with this parameter can be configured only when all
nodes of the cluster are running SGeRAC version A.11.18 or higher. For more information, see
the latest edition of the Managing Serviceguard Sixteenth Edition user guide at
www.hp.com/go/hpux-serviceguard-docs —> HP Serviceguard.
Figure 2-1 Single Network for Cluster Communications
Alternate Configuration—Fast Reconfiguration with Low Node Member Timeout
High RAC-IC traffic may interfere with SG-HB traffic and cause unnecessary member timeout
if Serviceguard cluster configuration parameter MEMBER_TIMEOUT is low. If MEMBER_TIMEOUT
cannot be increased, use of an additional network dedicated for SG-HB alone avoids unnecessary
member timeouts when RAC-IC traffic is high. This configuration is for a cluster with two or
more nodes that have high RAC-IC traffic and/or need faster failover (a low value for Serviceguard
configuration parameter MEMBER_TIMEOUT).
38 Serviceguard Configuration for Oracle 10g, 11gR1, or 11gR2 RAC