Managing HP Serviceguard for Linux Ninth Edition, April 2009

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 hub or switch.
Network interfaces are allowed to share IP addresses through a process known as
channel bonding. See “Implementing Channel Bonding (Red Hat)” (page 153) or
“Implementing Channel Bonding (SUSE)” (page 156).
Serviceguard supports a maximum of 30 network interfaces per node. For this purpose
an interface is defined as anything represented as a primary interface in the output of
ifconfig, so the total of 30 can comprise any combination of physical LAN interfaces
or bonding interfaces. (A node can have more than 30 such interfaces, but only 30 can
be part of the cluster configuration.)
Rules and Restrictions
• A single subnet cannot be configured on different network interfaces (NICs) on
the same node.
• In the case of subnets that can be used for communication between cluster nodes,
the same network interface must not be used to route more than one subnet
configured on the same node.
• For IPv4 subnets, Serviceguard does not support different subnets on the same
LAN interface.
— For IPv6, Serviceguard supports up to two subnets per LAN interface (site-local
and global).
• Serviceguard does support different subnets on the same bridged network (this
applies at both the node and the cluster level).
• Serviceguard does not support using networking tools such as ifconfig to add
IP addresses to network interfaces that are configured into the Serviceguard cluster,
30 Understanding Hardware Configurations for Serviceguard for Linux