This LFCS practice question tests your understanding of networking. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A network engineer needs to temporarily disable a network interface eth1 without bringing it down permanently. Which command?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "which command"
Why it matters: Tests specific CLI syntax. Recall the exact command and its required context — near-synonyms and partial matches are common distractors.
systemctl stop network
Why wrong: This stops the entire network service, affecting all interfaces.
ip link set eth1 down
This temporarily brings the interface down until manually brought up or reboot.
nmcli device disconnect eth1
Why wrong: This disconnects the interface but does not set it administratively down.
ifdown eth1
Why wrong: ifdown is network-scripts specific and may not be temporary if managed by NetworkManager.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
ip link set eth1 down
The `ip link set eth1 down` command temporarily disables the eth1 interface by changing its state to DOWN at the kernel level, without making any persistent changes to configuration files. This is the correct approach for a temporary disable because the interface can be re-enabled with `ip link set eth1 up` and will revert to its configured state upon reboot.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
systemctl stop network
Why it's wrong here
This stops the entire network service, affecting all interfaces.
ip link set eth1 down
Why this is correct
This temporarily brings the interface down until manually brought up or reboot.
Clue confirmation
The clue word "which command" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
nmcli device disconnect eth1
Why it's wrong here
This disconnects the interface but does not set it administratively down.
ifdown eth1
Why it's wrong here
ifdown is network-scripts specific and may not be temporary if managed by NetworkManager.
Common exam traps
The trap here is that candidates often confuse `ifdown eth1` as a temporary disable, but it can trigger persistent configuration changes or rely on deprecated tools, whereas `ip link set eth1 down` is the modern, stateless method for a temporary interface shutdown.
Detailed technical explanation
The `ip link set` command directly manipulates the netlink socket to change the interface's administrative state (IFF_UP flag) in the kernel, which is immediate and non-persistent. This contrasts with `ifdown`, which often invokes distribution-specific scripts that may modify state files or trigger DHCP release events. In real-world scenarios, using `ip link set eth1 down` is preferred for temporary maintenance because it avoids altering any configuration files and ensures the interface can be quickly restored without unintended persistence.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A practitioner preparing for the LFCS exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Networking — study guide chapter
Learn the concepts, then practise the questions
Networking practice questions
Targeted practice on this topic area only
All LFCS questions
513 questions across all exam domains
Linux Foundation Certified System Administrator LFCS study guide
Full concept coverage aligned to exam objectives
LFCS practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise LFCS questions linked to User and Group Management.
Practise LFCS questions linked to Operation of Running Systems.
Practise LFCS questions linked to Essential Commands.
Practise LFCS questions linked to Networking.
Practise LFCS questions linked to Service Configuration.
Practise LFCS questions linked to Storage Management.
Practise LFCS questions linked to LFCS fundamentals.
Practise LFCS questions linked to LFCS scenario.
Practise LFCS questions linked to LFCS troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Networking — This question tests Networking — Read the scenario before looking for a memorised answer..
The correct answer is: ip link set eth1 down — The `ip link set eth1 down` command temporarily disables the eth1 interface by changing its state to DOWN at the kernel level, without making any persistent changes to configuration files. This is the correct approach for a temporary disable because the interface can be re-enabled with `ip link set eth1 up` and will revert to its configured state upon reboot.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Yes — watch for: "which command". Tests specific CLI syntax. Recall the exact command and its required context — near-synonyms and partial matches are common distractors.
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Keep practising
Last reviewed: Jun 25, 2026
This LFCS practice question is part of Courseiva's free Linux Foundation certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the LFCS exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.