Managing HP Serviceguard for Linux, Tenth Edition, September 2012

loaded system when necessary) you can do so by putting each service in its own package
and giving it a unique IP address.
Bonding of LAN Interfaces
Several LAN interfaces on a node can be grouped together in a process known in Linux
as channel bonding. In the bonded group, typically one interface is used to transmit and
receive data, while the others are available as backups. If one interface fails, another
interface in the bonded group takes over. HP strongly recommends you use channel
bonding in each critical IP subnet to achieve highly available network services.
Host Bus Adapters (HBAs) do not have to be identical. Ethernet LANs must be the same
type, but can be of different bandwidth (for example 1 Gb and 100 Mb). Serviceguard
for Linux supports the use of bonding of LAN interfaces at the driver level. The Ethernet
driver is configured to employ a group of interfaces.
Once bonding is enabled, each interface can be viewed as a single logical link of
multiple physical ports with only one IP and MAC address. There is no limit to the number
of slaves (ports) per bond, and the number of bonds per system is limited to the number
of Linux modules you can load.
You can bond the ports within a multi-ported networking card (cards with up to four ports
are currently available). Alternatively, you can bond ports from different cards. HP
recommends that use different cards.Figure 22 shows an example of four separate
interfaces bonded into one aggregate.
How the Network Manager Works 71