A.ARP B.RARP C.SMTP D.ICMP
A.FTP B.HTTP C.DNS D.ICMP
A.發(fā)送方從下層向上層傳輸數(shù)據(jù),每經(jīng)過一層附加協(xié)議控制信息 B.接收方從下層向上層傳輸數(shù)據(jù),每經(jīng)過一層附加協(xié)議控制信息 C.發(fā)送方從上層向下層傳輸數(shù)據(jù),每經(jīng)過一層附加協(xié)議控制信息 D.接收方從上層向下層傳輸數(shù)據(jù),每經(jīng)過一層附加協(xié)議控制信息