- A
On a router-on-a-stick configuration, each subinterface must be configured with an IP address and the encapsulation dot1Q command to specify the VLAN ID.
This is correct because the router needs a subinterface per VLAN, each with an IP address and the dot1Q encapsulation to identify the VLAN.
- B
The native VLAN is always tagged on an 802.1Q trunk link.
Why wrong: This is incorrect because the native VLAN is specifically the VLAN that is not tagged on an 802.1Q trunk; all other VLANs are tagged.
- C
The command switchport trunk native vlan 10 is used to restrict which VLANs are allowed on a trunk.
Why wrong: This is incorrect because switchport trunk native vlan 10 sets the native VLAN to 10, not restricts allowed VLANs.
- D
When configuring a router-on-a-stick, the native VLAN must match on both the switch and the router subinterface to avoid miscommunication.
This is correct because if the native VLAN differs, the router may interpret untagged frames incorrectly, leading to connectivity issues.
- E
The command show interfaces trunk displays the IP addresses configured on router subinterfaces.
Why wrong: This is incorrect because show interfaces trunk is a switch command that shows trunk status and allowed VLANs, not router IP addresses.
Quick Answer
The correct answer identifies that when configuring a router-on-a-stick, the native VLAN must match on both the switch and the router subinterface to avoid miscommunication. This is because the switchport trunk sends native VLAN frames untagged, and the router’s subinterface (or physical interface) must be configured with the same native VLAN ID using the encapsulation dot1Q native command; if they differ, the router will mishandle those untagged frames, breaking inter-VLAN routing. On the CCNA 200-301 v2 exam, this concept tests your understanding of 802.1Q trunking mechanics and the critical role of native VLAN consistency in a router-on-a-stick topology—a common trap is assuming native VLAN frames are tagged, or that changing the native VLAN with switchport trunk native vlan also restricts allowed VLANs. Remember the memory tip: “Native must match, or traffic will catch”—untagged frames on the trunk must land on the same VLAN on both sides for seamless communication.
CCNA Switching and Network Access Practice Question
This 200-301 practice question tests your understanding of switching and network access. Examine the command output carefully: the correct answer depends on what the output actually shows, not on general recall alone. 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.
Which TWO statements are true about configuring and verifying VLANs, 802.1Q trunking, native VLAN, and inter-VLAN routing with router-on-a-stick?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
On a router-on-a-stick configuration, each subinterface must be configured with an IP address and the encapsulation dot1Q command to specify the VLAN ID.
Option A is correct because in a router-on-a-stick configuration, each subinterface must be assigned an IP address and use the encapsulation dot1Q command to associate it with a specific VLAN ID; this enables the router to process tagged frames from multiple VLANs over a single physical link. Option D is also correct because the native VLAN configured on the switchport trunk must match the native VLAN used on the router's subinterface (or physical interface if no subinterface); a mismatch causes the router to mishandle untagged frames because it expects them to belong to the configured native VLAN, leading to communication failures. Option B is wrong because on an 802.1Q trunk, the native VLAN frames are sent untagged, not tagged. Option C is wrong because the command 'switchport trunk native vlan 10' only changes the native VLAN; it does not restrict which VLANs are allowed—that requires 'switchport trunk allowed vlan'. Option E is wrong because 'show interfaces trunk' shows trunking status, native VLAN, and allowed VLAN lists on switch ports, not IP addresses of router subinterfaces.
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.
- ✓
On a router-on-a-stick configuration, each subinterface must be configured with an IP address and the encapsulation dot1Q command to specify the VLAN ID.
Why this is correct
This is correct because the router needs a subinterface per VLAN, each with an IP address and the dot1Q encapsulation to identify the VLAN.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
The native VLAN is always tagged on an 802.1Q trunk link.
Why it's wrong here
This is incorrect because the native VLAN is specifically the VLAN that is not tagged on an 802.1Q trunk; all other VLANs are tagged.
- ✗
The command switchport trunk native vlan 10 is used to restrict which VLANs are allowed on a trunk.
Why it's wrong here
This is incorrect because switchport trunk native vlan 10 sets the native VLAN to 10, not restricts allowed VLANs.
- ✓
When configuring a router-on-a-stick, the native VLAN must match on both the switch and the router subinterface to avoid miscommunication.
Why this is correct
This is correct because if the native VLAN differs, the router may interpret untagged frames incorrectly, leading to connectivity issues.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
The command show interfaces trunk displays the IP addresses configured on router subinterfaces.
Why it's wrong here
This is incorrect because show interfaces trunk is a switch command that shows trunk status and allowed VLANs, not router IP addresses.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 200-301 exam frequently reuses these exact scenarios with slightly different constraints.
✓On a router-on-a-stick configuration, each subinterface must be configured with an IP address and the encapsulation dot1Q command to specify the VLAN ID.Correct answer▾
Why this is correct
This is correct because the router needs a subinterface per VLAN, each with an IP address and the dot1Q encapsulation to identify the VLAN.
✗The native VLAN is always tagged on an 802.1Q trunk link.Wrong answer — click to see why▾
Why this is wrong here
The native VLAN is sent untagged to maintain backward compatibility with devices that do not understand 802.1Q tagging.
✗The command switchport trunk native vlan 10 is used to restrict which VLANs are allowed on a trunk.Wrong answer — click to see why▾
Why this is wrong here
The command to restrict allowed VLANs is switchport trunk allowed vlan, not the native VLAN command.
✗The command show interfaces trunk displays the IP addresses configured on router subinterfaces.Wrong answer — click to see why▾
Why this is wrong here
To see IP addresses on subinterfaces, use show ip interface brief or show running-config on the router.
Analysis generated from the official 200-301blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the misconception that the native VLAN is tagged on a trunk, or that the switchport trunk native vlan command controls allowed VLANs, when in fact it only changes which VLAN is untagged.
Trap categories for this question
Command / output trap
This is incorrect because show interfaces trunk is a switch command that shows trunk status and allowed VLANs, not router IP addresses.
Detailed technical explanation
How to think about this question
On an 802.1Q trunk, frames from the native VLAN are sent without a VLAN tag, which reduces overhead but requires both ends to agree on the native VLAN to avoid misconfiguration. In a router-on-a-stick setup, the native VLAN subinterface (if used) must be configured with encapsulation dot1Q <vlan-id> native to ensure the router does not tag frames for that VLAN, matching the switch's untagged behavior. This is critical because mismatched native VLANs can cause traffic to be placed in the wrong VLAN or dropped due to VLAN mismatch errors (e.g., CDP or DTP messages).
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 help-desk technician troubleshoots why a newly connected PC cannot reach shared printers on the same floor. The cable is good, the switch port is active, but the PC is in VLAN 20 and the printers are in VLAN 10. The uplink trunk only allows VLAN 10. A trunk being up does not mean every VLAN crosses it.
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.
- →
Switching and Network Access — study guide chapter
Learn the concepts, then practise the questions
- →
Switching and Network Access practice questions
Targeted practice on this topic area only
- →
All 200-301 questions
1,819 questions across all exam domains
- →
CCNA 200-301 v2 study guide
Full concept coverage aligned to exam objectives
- →
200-301 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related 200-301 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Network Infrastructure and Connectivity practice questions
Practise 200-301 questions linked to Network Infrastructure and Connectivity.
Switching and Network Access practice questions
Practise 200-301 questions linked to Switching and Network Access.
IP Routing practice questions
Practise 200-301 questions linked to IP Routing.
Network Services and Security practice questions
Practise 200-301 questions linked to Network Services and Security.
AI and Network Operations practice questions
Practise 200-301 questions linked to AI and Network Operations.
CCNA subnetting practice questions
Practise IPv4 subnetting, CIDR, masks, host ranges and subnet selection.
CCNA OSPF practice questions
Practise OSPF neighbours, router IDs, metrics, areas and routing-table interpretation.
CCNA VLAN practice questions
Practise VLANs, access ports, trunks, allowed VLANs and switching scenarios.
CCNA STP practice questions
Practise spanning tree, root bridge election, port roles and STP troubleshooting.
CCNA EtherChannel practice questions
Practise LACP, PAgP, port-channel behaviour and bundle requirements.
CCNA ACL practice questions
Practise standard and extended ACLs, permit/deny logic and traffic filtering.
CCNA NAT practice questions
Practise static NAT, dynamic NAT, PAT and inside/outside address translation.
Practice this exam
Start a free 200-301 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this 200-301 question test?
Switching and Network Access — This question tests Switching and Network Access — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: On a router-on-a-stick configuration, each subinterface must be configured with an IP address and the encapsulation dot1Q command to specify the VLAN ID. — Option A is correct because in a router-on-a-stick configuration, each subinterface must be assigned an IP address and use the encapsulation dot1Q command to associate it with a specific VLAN ID; this enables the router to process tagged frames from multiple VLANs over a single physical link. Option D is also correct because the native VLAN configured on the switchport trunk must match the native VLAN used on the router's subinterface (or physical interface if no subinterface); a mismatch causes the router to mishandle untagged frames because it expects them to belong to the configured native VLAN, leading to communication failures. Option B is wrong because on an 802.1Q trunk, the native VLAN frames are sent untagged, not tagged. Option C is wrong because the command 'switchport trunk native vlan 10' only changes the native VLAN; it does not restrict which VLANs are allowed—that requires 'switchport trunk allowed vlan'. Option E is wrong because 'show interfaces trunk' shows trunking status, native VLAN, and allowed VLAN lists on switch ports, not IP addresses of router subinterfaces.
What should I do if I get this 200-301 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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 →
Keep practising
More 200-301 practice questions
- A switchport connected to another switch should carry multiple VLANs, but it was manually configured as an access port.…
- What problem is HSRP designed to solve?
- Which TWO statements correctly describe the causes or implications of CRC errors, runts, giants, or output errors as see…
- You are connected to R1. Configure IPv4 and IPv6 addressing on R1's interfaces and verify reachability to R2. The curren…
- Which TWO statements accurately describe how AI/ML concepts are applied to network operations in modern enterprise netwo…
- Which TWO switch port configurations are required when connecting a Cisco IP phone and a desktop PC to a single access p…
Last reviewed: Jun 11, 2026
This 200-301 practice question is part of Courseiva's free Cisco 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 200-301 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.