(1)   		6LN ----(RS)-------> 6LR
            (2)   		6LN <---(RA-PIO)---- 6LR
            (3)   		6LN ----(NS-EARO)--> 6LR
            (4)	                [Multihop DAD procedure] 
            (5)	          	6LN <---(NA)-------- 6LR