The value of this object identifies whether an interface is enabled to become a backup interface in Loop Free Alternate (LFA) calculation.
Null(0): disables an interface from becoming a backup interface in LFA calculation.
level1(1): specifies an interface as a backup interface in Level-1.
level2(2): specifies an interface as a backup interface in Level-2.
level12(3): specifies an interface as a backup interface in Level-1 and Level-2.