Use an unprivileged command to inspect the path to 198.51.100.20 and the estimated path MTU.
Which command is appropriate?
tracepath follows the path and reports path MTU information; it normally does not require raw-socket privileges.
Detailed explanation
ip link show 198.51.100.20Incorrect. It displays local link information and does not trace a remote path.
Incorrect. It displays local link information and does not trace a remote path.
ss --pmtu 198.51.100.20Incorrect. This is not a standard ss syntax for path MTU discovery.
Incorrect. This is not a standard ss syntax for path MTU discovery.
tracepath 198.51.100.20Correct. tracepath reports the path and path MTU information.
Correct. tracepath reports the path and path MTU information.
route --mtu 198.51.100.20Incorrect. The legacy route command does not discover a remote path MTU this way.
Incorrect. The legacy route command does not discover a remote path MTU this way.
Try it yourself
An example you can run in a temporary verification environment.
printf '%s
' 'tracepath -> hops and path MTU observations'Expected result
tracepath -> hops and path MTU observationsKey points
- Path MTU discovery
- Observe intermediate hops
- Usable by ordinary users
Notes
- Environment: iputils tracepathの動作対応表（外部通信なし）
- 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.