This object sets the preemption mode of a Smart Link group, controlling how the group decides to switch traffic back to a preferred link. An admin chooses between none(1), role(2, preempt based on primary/secondary role), or speed(3, preempt based on link speed) to control failback behavior after a failed link recovers. Setting this to role(2) means the group automatically switches traffic back to the primary port once it comes back up, rather than staying on the secondary.