Use ordinary IPv4 ping to test host reachability and round-trip time.
Which messages are used?
IPv4 ping sends ICMP Echo Request and observes Echo Reply; it does not use a TCP or UDP port.
Detailed explanation
TCP SYN / ACKIncorrect. TCP SYN/ACK tests a port connection rather than ordinary ping.
Incorrect. TCP SYN/ACK tests a port connection rather than ordinary ping.
UDP DNS query / responseIncorrect. DNS queries resolve names.
Incorrect. DNS queries resolve names.
ARP request / replyだけIncorrect. ARP is local-link address resolution.
Incorrect. ARP is local-link address resolution.
ICMP Echo Request / Echo ReplyCorrect. ICMP Echo messages implement IPv4 ping.
Correct. ICMP Echo messages implement IPv4 ping.
Try it yourself
An example you can run in a temporary verification environment.
printf '%s
' 'ping -> ICMP Echo Request / Echo Reply'Expected result
ping -> ICMP Echo Request / Echo ReplyKey points
- ICMP control protocol
- Echo Request/Reply
- No port number
Notes
- Environment: protocol対応表の表示のみ
- Command output formatting can vary slightly by distribution or tool version.
- Run the example in a temporary directory or process when possible.
Foundation review
Read the scope first
Check whether the command acts on the current shell, a new process, an existing process, or a file.
Verify the observable result
Use the supplied command and compare the output with the expected result.