Identifying local service versions | LinuC Level 1 102 Exam original practice question

1.10.1Basic

Use nmap against localhost only to estimate services and versions on TCP ports 22, 80, and 443.

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.

nmap -sV -p 22,80,443 127.0.0.1: Correct. It performs service/version detection on the three local TCP ports.
nmap -sn 127.0.0.1: Incorrect. -sn performs host discovery without a port scan.
nmap -O -p 22,80,443 127.0.0.1: Incorrect. -O performs OS detection rather than service-version detection.
nmap -sU -p 22,80,443 127.0.0.1: Incorrect. -sU selects UDP scanning.

Detailed explanation

Correctnmap -sV -p 22,80,443 127.0.0.1

Correct. It performs service/version detection on the three local TCP ports.

Incorrectnmap -sn 127.0.0.1

Incorrect. -sn performs host discovery without a port scan.

Incorrectnmap -O -p 22,80,443 127.0.0.1

Incorrect. -O performs OS detection rather than service-version detection.

Incorrectnmap -sU -p 22,80,443 127.0.0.1

Incorrect. -sU selects UDP scanning.

An example you can run in a temporary verification environment.

nmap --help 2>&1 | grep -E -- '-sV|VERSION DETECTION' | head -n 2

-sVまたはVERSION DETECTIONの説明行

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 IDKL-102-1123

EnvironmentNmap help / scanは実行しない

Last technical review2026-08-13