HP Serviceguard A.11.20- Managing Serviceguard Twentieth Edition, August 2011

configured into the Serviceguard cluster, unless those IP addresses themselves will be
immediately configured into the cluster as stationary IP addresses.
CAUTION: If you configure any address other than a stationary IP address on a Serviceguard
network interface, it could collide with a relocatable package IP address assigned by
Serviceguard. See “Stationary and Relocatable IP Addresses ” (page 67).
(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 LAN card for the data/heartbeat subnet (subnetA). Another LAN card 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 LAN card for the data/heartbeat subnet,
Serviceguard will perform a local switch to the standby LAN card 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.
Redundant Network Components 29