Managing Serviceguard 14th Edition, June 2007

IPv6 Network Support
Local Primary/Standby LAN Patterns
Appendix H516
Local Primary/Standby LAN Patterns
The use of IPv6 allows a number of different patterns of failover among
LAN cards configured in the cluster. This is true because each LAN card
can support several IP addresses when a dual IPv4/IPv6 configuration is
used. This section describes several ways in that local failover to a
standby LAN can be configured.
By definition, a standby network interface is an interface that has no IP
address(es) of either address family (IPv4 or IPv6) and is bridged to the
primary network interface on a node.
Here are two guidelines to keep in mind when using IPv4 and IPv6
addresses in local failover situations:
• Since a network interface card can have both an IPv4 and an IPv6
address as the primary IPs, the standby network interface card could
potentially act as a standby for both types of primary interfaces.
However, if the IPv4 and IPv6 address(es) are configured on two
separate network interfaces, then the standby interface can take
over the IP address from only one network interface during a local
failover.
That is, IPv4 and IPv6 addresses from two separate network
interfaces are mutually exclusive in a failover condition.
• Serviceguard will switch over link-local address configured on the
primary network interface along with all other IP addresses which
are configured as part of the cluster configuration to the standby
network interface. This includes all heartbeat and stationary IPs
(IPv4 and IPv6) and package IPs (both IPv4 and IPv6) added by
Serviceguard.
The examples that follow illustrate this.