TIsisLevel
Indicates the ISIS Route Level match criterion. A value of 0 indicates no IS-IS route match criterion is configured. There are two types of areas in IS-IS, namely Level 1 areas and Level 2 areas. Routers within a Level 1 area route to other routers in that area. If the destination does not exist within the area, the Level 1 router will route toward a Level 2 router. Level 2 routers route between areas and toward other ASs.