This LFCS practice question tests your understanding of networking. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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.
An administrator wants to ensure that a service is listening on TCP port 8080 and accessible from remote hosts. Which command will confirm that the service is listening on the correct interface?
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.
iptables -L
Why wrong: Shows firewall rules, not listening ports.
netstat -i
Why wrong: Shows interface statistics, not listening ports.
ss -tlnp
Shows listening TCP sockets with process and address.
ip addr
Why wrong: Shows IP addresses assigned to interfaces.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
ss -tlnp
Option C is correct because the `ss -tlnp` command displays listening (`-l`) TCP (`-t`) sockets with numeric addresses (`-n`) and the associated process (`-p`), which directly confirms that a service is bound to TCP port 8080 on a specific interface (e.g., 0.0.0.0:8080 or 192.168.1.10:8080). This ensures the service is listening on the correct interface and is reachable from remote hosts.
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.
iptables -L
Why it's wrong here
Shows firewall rules, not listening ports.
netstat -i
Why it's wrong here
Shows interface statistics, not listening ports.
ss -tlnp
Why this is correct
Shows listening TCP sockets with process and address.
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.
ip addr
Why it's wrong here
Shows IP addresses assigned to interfaces.
Common exam traps
The trap here is that candidates confuse commands that show network configuration or firewall rules with those that show actual listening sockets, leading them to pick `iptables -L` or `ip addr` instead of `ss -tlnp`.
Trap categories for this question
Command / output trap
Shows firewall rules, not listening ports.
Detailed technical explanation
The `ss` command reads socket information from the `/proc/net/tcp` and `/proc/net/tcp6` files (or uses netlink for faster access), providing detailed state information such as LISTEN, ESTABLISHED, and the bound IP:port. In real-world scenarios, a service might bind to 127.0.0.1:8080 (loopback only) instead of 0.0.0.0:8080 (all interfaces), making it inaccessible from remote hosts; `ss -tlnp` clearly shows the bound address, unlike firewall or interface commands.
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: ss -tlnp — Option C is correct because the `ss -tlnp` command displays listening (`-l`) TCP (`-t`) sockets with numeric addresses (`-n`) and the associated process (`-p`), which directly confirms that a service is bound to TCP port 8080 on a specific interface (e.g., 0.0.0.0:8080 or 192.168.1.10:8080). This ensures the service is listening on the correct interface and is reachable from remote hosts.
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 →
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.