A.255.255.255.252 B.255.255.255.128 C.255.255.0.0 D.255.255.255.192
A.10.254.255.23 B.10.254.255.24 C.10.254.255.255 D.10.255.255.255
A.物理層 B.數(shù)據(jù)鏈路層 C.網(wǎng)絡(luò)層 D.傳輸層