A.以太網(wǎng)是基于共享介質(zhì)的網(wǎng)絡(luò) B.以太網(wǎng)采用CSMA/CD機制 C.以太網(wǎng)傳輸距離短,最長傳輸距離為500m D.以上說法均不正確
A.物理層B.數(shù)據(jù)鏈路層C.網(wǎng)絡(luò)層D.傳輸層
A.Time Exceeded B.Echo Request C.Echo Reply D.Port Unreachable