Managing HP Serviceguard for Linux, Tenth Edition, September 2012

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 162) or “Implementing
Channel Bonding (SUSE)” (page 165).
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,
Redundant Network Components 25