判断题
A.MP_REACH_NLRIB.NLRI MP_UNREACH_NLRIC.MP_REACH_Next_HopD.MP_MED
A.IGPB.EGPC.OSPFD.IS-ISE.incomplete
A.IBGPB.EGPC.LBGPD.EBGP
A.IdleB.ActiveC.EstablishedD.InactiveE.Passive
A.5B.15C.30D.60
A.30B.60C.90D.180
A.1字节和2字节B.2字节和4字节C.3字节和6字节D.4字节和8字节
A.TCP（端口179）B.TCP（端口79）C.UDP（端口179）D.TCP（端口69）