Verify the same host's IPv6 stack without sending traffic outside the host.
Finish after three echo requests.
Which command is appropriate?
::1 is IPv6 loopback, so ping -6 -c 3 ::1 sends exactly three requests within the same host.
Detailed explanation
ping -4 -c 3 ::1Incorrect. -4 forces IPv4 while ::1 is IPv6.
Incorrect. -4 forces IPv4 while ::1 is IPv6.
ping -6 -c 3 ::1Correct. It tests IPv6 loopback three times.
Correct. It tests IPv6 loopback three times.
ping -6 -c 3 ff02::1Incorrect. ff02::1 is all-nodes link-local multicast, not host-only loopback.
Incorrect. ff02::1 is all-nodes link-local multicast, not host-only loopback.
ping -4 -c 3 0.0.0.0Incorrect. It uses IPv4 unspecified address and is not an IPv6 loopback test.
Incorrect. It uses IPv4 unspecified address and is not an IPv6 loopback test.
Try it yourself
An example you can run in a temporary verification environment.
ping -h 2>&1 | grep -E -- '-4|-6|-c' | head -n 2Expected result
IPバージョン選択と送信回数を示すhelp行Key points
- ::1 is IPv6 loopback
- -6 selects IPv6
- -c 3 limits requests
Notes
- Environment: iputils ping help / パケット送信なし
- 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.