LPIC-2 Advanced Networking Configuration Practice Question
This LPIC-2 practice question tests your understanding of advanced networking configuration. 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.
An administrator configures a bridge br0 with two ports (eth0 and eth1). The network uses STP. After configuration, packets from a host on eth0 to a host on eth1 are not forwarded. The bridge shows blocking state for one of the ports. What is the most likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The bridge has loop detection and blocked one port
The bridge br0 has two ports (eth0 and eth1) and STP is enabled. STP detects a loop in the network — in this case, the bridge itself with two ports on the same broadcast domain creates a loop. To prevent broadcast storms and MAC table instability, STP places one of the ports into the blocking state, which stops forwarding frames between the two ports. This is why packets from a host on eth0 to a host on eth1 are not forwarded.
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.
✗
Incorrect MTU
Why it's wrong here
MTU mismatch may cause fragmentation issues, not blocking state.
✗
STP is disabled
Why it's wrong here
If STP disabled, both ports would be forwarding, so not cause of blocking.
✗
MAC address learning is disabled
Why it's wrong here
Disabling learning would flood packets but not cause STP blocking.
✗
The bridge is in promiscuous mode
Why it's wrong here
Promiscuous mode affects packet capture, not blocking state.
✓
The bridge has loop detection and blocked one port
Why this is correct
STP blocks redundant paths to prevent loops, which can cause one port to be in blocking state.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often think STP only blocks ports when there are multiple switches in a loop, but STP also blocks ports on a single bridge with two ports in the same broadcast domain because it sees a loop between its own ports.
Detailed technical explanation
How to think about this question
STP (IEEE 802.1D) elects a root bridge and calculates the best path to it, blocking redundant ports to prevent Layer 2 loops. In a simple two-port bridge, both ports are in the same broadcast domain, so STP sees a loop and blocks one port — this is a common scenario when bridging two interfaces on the same host without any external switches. The blocked port transitions through listening and learning states before reaching forwarding, but if the bridge detects itself as the root and both ports are on the same LAN, one port remains blocked indefinitely.
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 network engineer segments a warehouse floor into three subnets: 20 scanners, 5 printers, and 2 management hosts. Picking the wrong mask wastes addresses or leaves too few usable hosts. Exam questions test whether you can apply CIDR notation, calculate block size, and identify the correct usable-host range for a given prefix.
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.
Advanced Networking Configuration — This question tests Advanced Networking Configuration — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The bridge has loop detection and blocked one port — The bridge br0 has two ports (eth0 and eth1) and STP is enabled. STP detects a loop in the network — in this case, the bridge itself with two ports on the same broadcast domain creates a loop. To prevent broadcast storms and MAC table instability, STP places one of the ports into the blocking state, which stops forwarding frames between the two ports. This is why packets from a host on eth0 to a host on eth1 are not forwarded.
What should I do if I get this LPIC-2 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: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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 LPIC-2 practice question is part of Courseiva's free LPI 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 LPIC-2 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.