By default, active interfaces that have failed and then been automatically repaired become active interfaces in the IPMP group again. This behavior is controlled by the value of the FAILBACK parameter in the in.mpathd daemon's configuration file. However, even an insignificant disruption that occurs as data addresses are remapped to repaired interfaces might not be acceptable. In this case, you might prefer to enable an activated standby interface to continue as an active interface. IPMP allows you to override the default behavior to prevent an interface from automatically becoming active upon repair. These interfaces must be configured in the FAILBACK=no mode. See How to Configure the Behavior of the IPMP Daemon.
When an active interface in FAILBACK=no mode fails and is subsequently repaired, the in.mpathd daemon restores the IPMP configuration as follows:
The daemon retains the interface's INACTIVE status, provided that the IPMP group reflects the original configuration of active interfaces.
If the IPMP configuration at the moment of repair does not reflect the group's original configuration of active interfaces, then the repaired interface is redeployed as an active interface, notwithstanding the FAILBACK=no status.