Managing Serviceguard 14th Edition, June 2007

Understanding Serviceguard Hardware Configurations
Redundant Network Components
Chapter 238
Redundant Network Components
To eliminate single points of failure for networking, each subnet accessed
by a cluster node is required to have redundant network interfaces.
Redundant cables are also needed to protect against cable failures. Each
interface card is connected to a different cable, and the cables themselves
are connected by a component such as a hub or a bridge. This
arrangement of physical cables connected to each other via a bridge or
concentrator or switch is known as a bridged net.
IP addresses can be associated with interfaces on a bridged net. An
interface that has an IP address associated with it is known as a
primary interface, and an interface that does not have an IP address
associated with it is known as a standby interface. Standby interfaces
are those which are available for switching by Serviceguard if a failure
occurs on the primary. When Serviceguard detects a primary interface
failure, it will switch the IP addresses and any associated connections
from the failed interface card to a healthy standby interface card.
Serviceguard supports a maximum of 30 network interfaces per node.
For this purpose an interface is defined as anything represented as a
LAN interface in the output of lanscan (1m), so the total of 30 can
comprise any combination of physical LAN ports, VLAN ports, IPoIB
interfaces and APA aggregates. (A node can have more than 30 such
interfaces, but only 30 can be part of the cluster configuration.)
A selection of network configurations is described further in the
following sections. See also “How the Network Manager Works” on
page 98. For detailed information about supported network
configurations, consult Hewlett-Packard support.
NOTE Serial (RS232) lines are no longer supported for the cluster heartbeat.
Fibre Channel, Token Ring and FDDI networks are no longer supported
as heartbeat or data LANs.
Redundant Ethernet Configuration
The use of redundant network components is shown in Figure 2-1, which
is an Ethernet configuration.