Auditing listening ports and processes | LPIC-1 102-500 Exam original practice question

110.1Standard

Use netstat to display listening TCP and UDP sockets numerically and show PID and program names where permitted.

Which command is appropriate?

Hint 1: Focus on the requirement

Identify what must change and what must remain unchanged. Then choose the command whose scope matches that requirement.

Hint 2: Check each command's role

Separate commands that display information, change state, remove data, or affect a child process.

netstat -ant: Incorrect. It shows all TCP sockets and omits UDP, listener filtering, and processes.
netstat -rnp: Incorrect. It displays a numeric routing table.
netstat -tulpn: Correct. It lists TCP/UDP listeners with process and numeric information.
netstat -i: Incorrect. It displays interface statistics.

Detailed explanation

Incorrectnetstat -ant

Incorrect. It shows all TCP sockets and omits UDP, listener filtering, and processes.

Incorrectnetstat -rnp

Incorrect. It displays a numeric routing table.

Correctnetstat -tulpn

Correct. It lists TCP/UDP listeners with process and numeric information.

Incorrectnetstat -i

Incorrect. It displays interface statistics.

An example you can run in a temporary verification environment.

printf '%s
' '-t=TCP' '-u=UDP' '-l=listening' '-p=PID/program' '-n=numeric'

-t=TCP
-u=UDP
-l=listening
-p=PID/program
-n=numeric

Foundation review

Check whether the command acts on the current shell, a new process, an existing process, or a file.

Use the supplied command and compare the output with the expected result.

Question IDKP-110-851

Environmentnet-tools netstatのoption対応表

Last technical review2026-08-13