When you use the ping command to send ICMP messages across a network, what's the most common request/reply pair you'll see? (Select one answer choice)

A．Echo request and Echo reply

B．ICMP hold and ICMP send

C．ICMP request and ICMP reply

D．Echo off and Echo on

E．None of the above

参考答案

正确答案：A
解析：Explanation:TheICMPprotocolusesEchorequestandEchoreplywiththePingcommand.ThePINGutilityisthemostcommonlyusedmessagetoverifyconnectivitytoaremotedevicewithinthenetwork.