Link-based failure detection is always enabled, provided that the interface supports this type of failure detection.
To determine whether a third-party interface supports link-based failure detection, use the ipmpstat -i command. If the output for a given interface includes an unknown status for its LINK column, then that interface does not support link-based failure detection. Refer to the manufacturer's documentation for more specific information about the device.
These network drivers that support link-based failure detection monitor the interface's link state and notify the networking subsystem when that link state changes. When notified of a change, the networking subsystem either sets or clears the RUNNING flag for that interface, as appropriate. If the in.mpathd daemon detects that the interface's RUNNING flag has been cleared, the daemon immediately fails the interface.