Question 1easymultiple choice
Full question →easymultiple choiceObjective-mapped
Which STP port state on a classic 802.1D switch listens for BPDUs and prepares to participate in the topology, but does not yet learn MAC addresses?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Best answer
Listening
Listening comes before learning and does not yet learn MACs.
B
Distractor review
Learning
Learning does begin populating the MAC table.
C
Distractor review
Forwarding
Forwarding sends user traffic.
D
Distractor review
Disabled
Disabled does not participate in STP.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is selecting the Learning state as the answer because it involves MAC address table population, which is closely associated with port readiness. However, the question specifically asks for the state where the port listens for BPDUs and prepares to participate without learning MAC addresses. The Listening state fits this description exactly. Confusing these two states can lead to incorrect answers, as Learning ports do start populating the MAC table, unlike Listening ports. Understanding this subtle but critical difference is essential to avoid this trap on the CCNA exam.
Technical deep dive
How to think about this question
Spanning Tree Protocol (STP) is a Layer 2 network protocol designed to prevent loops in Ethernet networks by selectively blocking redundant paths. Classic STP, defined in IEEE 802.1D, uses a series of port states to manage how switches participate in the topology. The Listening state is a transitional phase where a switch port processes Bridge Protocol Data Units (BPDUs) to understand the network topology but does not yet learn MAC addresses or forward frames. This state ensures the port is ready to participate in the network without causing loops. During the Listening state, the switch port listens for BPDUs to confirm the topology and prepares to transition to the Learning state if no loops are detected. The Listening state precedes Learning and Forwarding states, acting as a safeguard to prevent premature forwarding of frames that could cause loops. Only after the Listening state does the port begin populating the MAC address table in the Learning state, and eventually forward user traffic in the Forwarding state. A common exam trap is confusing the Listening and Learning states because both occur before forwarding. However, the key difference is that Listening ports do not learn MAC addresses, while Learning ports do. Practically, this means that during Listening, the switch is still stabilizing the topology. Misunderstanding this can lead to incorrect answers about when a port starts populating the MAC table or forwarding traffic, which is critical for CCNA exam success and real-world network stability.
KKey Concepts to Remember
- The Listening state in classic 802.1D STP processes BPDUs but does not learn MAC addresses or forward frames.
- A switch port in the Listening state prepares to participate in the topology by confirming no loops exist before learning begins.
- The Learning state follows Listening and is when the switch populates the MAC address table without forwarding user traffic.
- The Forwarding state allows a port to send and receive user data frames after topology stability is confirmed.
- The Disabled state does not participate in STP and neither processes BPDUs nor forwards frames.
- STP uses port states sequentially to prevent loops: Disabled, Blocking, Listening, Learning, and Forwarding.
- Listening ports help stabilize the network topology by ensuring no loops before MAC learning and forwarding occur.
- Confusing Listening and Learning states is a common exam trap because both precede forwarding but have distinct functions.
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.
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More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A router learns the same prefix from both OSPF and EIGRP. Which route is installed by default?
Question 2
A router shows this output: R1#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.1.1.2 1 FULL/DR 00:00:34 192.168.12.2 GigabitEthernet0/0 10.1.1.3 1 2WAY/DROTHER 00:00:39 192.168.12.3 GigabitEthernet0/0 Which statement is correct?
Question 3
What is the OSPF metric called?
Question 4
A non-root switch has two uplinks toward the root bridge. One path has a lower total STP cost than the other. What role will the lower-cost uplink have?
Question 5
A router interface applies this ACL inbound: 10 deny tcp any any eq 80 20 permit ip any any A user reports that web browsing to a server by IP address fails, but ping works. Which statement best explains the behavior?
Question 6
A router learns route 198.51.100.0/24 from OSPF with AD 110 and also has a static route to the same prefix configured with AD 150. Which route is installed?
FAQ
Questions learners often ask
What does this 200-301 question test?
The Listening state in classic 802.1D STP processes BPDUs but does not learn MAC addresses or forward frames.
What is the correct answer to this question?
The correct answer is: Listening — In classic STP, the listening state processes BPDUs and waits before learning begins. The learning state is when the switch starts populating the MAC table.
What should I do if I get this 200-301 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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