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.
A company is designing a multi-homed server with two network interfaces: one for internal traffic (eth0) and one for external traffic (eth1). The server must prioritize traffic to the 10.1.0.0/16 network through eth0. What is the best practice to ensure traffic to 10.1.0.0/16 uses eth0?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "best"
Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Add a static route for 10.1.0.0/16 via the gateway on eth0.
Adding a static route for 10.1.0.0/16 via the gateway on eth0 directly tells the kernel to send traffic destined for that network through eth0. This is the simplest and most direct method, ensuring that the route is always preferred over the default route for that specific destination, without affecting other traffic.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
Add a static route for 10.1.0.0/16 via the gateway on eth0.
Why this is correct
A static route directs traffic for that subnet to the correct interface.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
Configure policy routing using ip rule and two routing tables.
Why it's wrong here
Policy routing is not necessary for a simple static route.
✗
Set a lower metric on the default route for eth0.
Why it's wrong here
Metrics affect default gateway selection, not specific subnets.
✗
Use bonding to combine both interfaces.
Why it's wrong here
Bonding is for fault tolerance or throughput, not for routing specific subnets.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse policy routing (Option B) as the only way to control interface selection, but a simple static route is the standard and best practice for directing traffic to a specific subnet.
Detailed technical explanation
How to think about this question
Under the hood, the Linux kernel uses the Routing Policy Database (RPDB) and the Forwarding Information Base (FIB) to make forwarding decisions. A static route for 10.1.0.0/16 adds an entry to the FIB with a specific metric (default 0), which is always preferred over a default route (metric typically 100 or higher) for matching destinations. In a real-world scenario, if the gateway on eth0 is 10.1.0.1, the command would be 'ip route add 10.1.0.0/16 via 10.1.0.1 dev eth0', ensuring that internal traffic never leaks out the external interface.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Networking — This question tests Networking — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Add a static route for 10.1.0.0/16 via the gateway on eth0. — Adding a static route for 10.1.0.0/16 via the gateway on eth0 directly tells the kernel to send traffic destined for that network through eth0. This is the simplest and most direct method, ensuring that the route is always preferred over the default route for that specific destination, without affecting other traffic.
What should I do if I get this LFCS question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
What is the key concept behind this question?
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 →
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.
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.