Managing Serviceguard A.11.20, March 2013

(Oracle VIPs are an exception to this rule; such configurations require the HP add-on product
Serviceguard Extension for Oracle RAC).
◦ Similarly, Serviceguard does not support using networking tools to move or reconfigure
any IP addresses configured into the cluster.
Doing so leads to unpredictable results because the Serviceguard view of the configuration
is different from the reality.
NOTE: If you will be using a cross-subnet configuration, see also the Restrictions (page 30) that
apply specifically to such configurations.
Redundant Ethernet Configuration
The use of redundant network components is shown in Figure 4, which is an Ethernet configuration.
Figure 4 Redundant LANs
In the figure, a two-node Serviceguard cluster has one bridged net configured with both a primary
and a standby NIC for the data/heartbeat subnet (subnetA). Another NIC provides an optional
dedicated heartbeat LAN. Note that the primary and standby LAN segments are connected by a
hub to provide a redundant data/heartbeat subnet. Each node has its own IP address for this
subnet. In case of a failure of a primary NIC for the data/heartbeat subnet, Serviceguard will
perform a local switch to the standby NIC on the same node.
Redundant heartbeat is provided by the primary LAN and the dedicated LAN which are both
carrying the heartbeat. In Figure 4, local switching is not needed for the dedicated heartbeat LAN,
since there is already a redundant path via the other subnet. In case of data congestion on the
primary LAN, the dedicated heartbeat LAN will prevent a false diagnosis of heartbeat failure.
Each node has its own IP address for the dedicated heartbeat LAN.
NOTE: You should verify that network traffic is not too heavy on the heartbeat/data LAN. If traffic
is too heavy, this LAN might not perform adequately in transmitting heartbeats if the dedicated
heartbeat LAN fails.
Cross-Subnet Configurations
As of Serviceguard A.11.18 it is possible to configure multiple subnets, joined by a router, both
for the cluster heartbeat and for data, with some nodes using one subnet and some another.
Redundant Network Components 29