Managing Serviceguard 11th Edition, Version A.11.16, Second Printing June 2004

Understanding Serviceguard Software Components
How the Network Manager Works
Chapter 3 97
adoptive node if control of the package is transferred. This means that
applications can access the package via its relocatable address without
knowing which node the package currently resides on.
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. Only IPv4 addresses are supported as
heartbeat addresses, but both IPv4 and IPv6 addresses (including
various combinations) can be defined as stationary IPs in a cluster. Both
IPv4 and IPv6 addresses also can be used as relocatable (package) IP
addresses.
Adding and Deleting Relocatable IP Addresses
When a package is started, a relocatable IP address can be added to a
specified IP subnet. When the package is stopped, the relocatable IP
address is deleted from the specified subnet. Adding and removing of
relocatable IP addresses is handled through the cmmodnet command in
the package control script, which is described in detail in Chapter 6,
“Configuring Packages and Their Services,” on page 243
IP addresses are configured only on each primary network interface
card; standby cards are not configured with an IP address. Multiple IPv4
addresses on the same network card must belong to the same IP subnet.
Load Sharing
In one package, it is possible to have multiple services that are
associated with the same IP address. If one service is moved to a new
system, then the other services using the IP address will also be
migrated. Load sharing can be achieved by making each service its own
package and giving it a unique IP address. This gives the administrator
the ability to move selected services to less loaded systems.
Monitoring LAN Interfaces and Detecting Failure
At regular intervals, Serviceguard polls all the network interface cards
specified in the cluster configuration file. Network failures are detected
within each single node in the following manner. One interface on the