The following are the IPMP software components:
Multipathing daemon (in.mpathd) - Detects interface failures and repairs. The daemon performs both link-based failure detection and probe-based failure detection if test addresses are configured for the underlying interfaces. Depending on the type of failure detection method that is used, the daemon sets or clears the appropriate flags on the interface to indicate whether the interface failed or has been repaired. As an option, you can also configure the daemon to monitor the availability of all interfaces, including interfaces that are not configured to belong to an IPMP group. For a description of failure detection, see Failure Detection in IPMP.
The in.mpathd daemon also controls the designation of active interfaces in the IPMP group. The daemon attempts to maintain the same number of active interfaces that was originally configured when the IPMP group was created. Thus, in.mpathd activates or deactivates underlying interfaces as needed to be consistent with the administrator's configured policy. For more information about how the in.mpathd daemon manages the activation of underlying interfaces, see How IPMP Works. For more information about the daemon, refer to the in.mpathd (1M) man page.
IP kernel module - Manages outbound load spreading by distributing the set of available IP data addresses in the IPMP group across the set of available underlying IP interfaces in the group. The module also performs source address selection to manage inbound load spreading. Both roles of the module improve network traffic performance.
IPMP configuration file (/etc/default/mpathd) - Defines the daemon's behavior.
You customize the file to set the following parameters:
Target interfaces to probe when running probe-based failure detection
Time duration to probe a target to detect failure
Status with which to flag a failed interface after that interface is repaired
Scope of IP interfaces to monitor, whether to also include IP interfaces in the system that are not configured to belong to IPMP groups
For information about how to modify the configuration file, see How to Configure the Behavior of the IPMP Daemon.
ipmpstat command - Provides different types of information about the status of IPMP as a whole. The tool also displays other information about the underlying IP interfaces for each IPMP group, as well as data and test addresses that have been configured for the group. For more information about this command, see Monitoring IPMP Information and the ipmpstat (1M) man page.