This object sets the preference level, from 1 (low) to 10 (high), determining how likely the primary line is to become the active line in the redundancy group, defaulting to 5 so both lines start equal. Admins raise this above the secondary line's weight when they want to bias failover behavior toward a specific line becoming and staying active. Setting it to 8 while the secondary stays at 5 would favor the primary line whenever both are available.