A.向目標(biāo)主機(jī)發(fā)送UDP Echo Request數(shù)據(jù)包,等待對(duì)方回應(yīng)UDP Echo Reply數(shù)據(jù)包
B.向目標(biāo)主機(jī)發(fā)送ICMP Echo Request數(shù)據(jù)包,等待對(duì)方回應(yīng)ICMP Echo Reply數(shù)據(jù)包
C.向目標(biāo)主機(jī)發(fā)送UDP Echo Reply數(shù)據(jù)包,等待對(duì)方回應(yīng)ICMP Echo Request數(shù)據(jù)包
D.向目標(biāo)主機(jī)發(fā)送ICMP Echo Reply數(shù)據(jù)包,等待對(duì)方回應(yīng)ICMP Echo Request數(shù)據(jù)包