Managing HP Serviceguard for Linux, Tenth Edition, September 2012

IMPORTANT: Any subnet that is used by a package for relocatable addresses should
be configured into the cluster via NETWORK_INTERFACE and either STATIONARY_IP
or HEARTBEAT_IP in the cluster configuration file. For more information about those
parameters, see “Cluster Configuration Parameters ” (page 103). For more information
about configuring relocatable addresses, see the descriptions of the package ip_
parameters (page 214).
NOTE: It is possible to configure a cluster that spans subnets joined by a router, with
some nodes using one subnet and some another. This is called a cross-subnet
configuration. In this context, you can configure packages to fail over from a node on
one subnet to a node on another, and you will need to configure a relocatable address
for each subnet the package is configured to start on; see “About Cross-Subnet Failover”
(page 151), and in particular the subsection “Implications for Application Deployment”
(page 152).
Types of IP Addresses
Both IPv4 and IPv6 address types are supported in Serviceguard. IPv4 addresses are the
traditional addresses of the form n.n.n.n where n is a decimal digit between 0 and
255. IPv6 addresses have the form x:x:x:x:x:x:x:x where x is the hexadecimal
value of each of eight 16-bit pieces of the 128-bit address. You can define heartbeat
IPs, stationary IPs, and relocatable (package) IPs as IPv4 or IPv6 addresses (or certain
combinations of both).
Adding and Deleting Relocatable IP Addresses
When a package is started, any relocatable IP addresses configured for that package
are added to the specified IP subnet. When the package is stopped, the relocatable IP
address is deleted from the subnet. These functions are performed by the cmmodnet
command in the package master control script (package control script for legacy
packages).
IP addresses are configured only on each primary network interface card. Multiple IPv4
addresses on the same network card must belong to the same IP subnet.
CAUTION: HP strongly recommends that you add relocatable addresses to packages
only by editing ip_address (page 215) in the package configuration file (or IP []
entries in the control script of a legacy package) and running cmapplyconf (1m).
Load Sharing
Serviceguard allows you to configure several services into a single package, sharing a
single IP address; in that case all those services will fail over when the package does. If
you want to be able to load-balance services (that is, move a specific service to a less
70 Understanding Serviceguard Software Components