- A
Configure the access switches with VPC (Virtual Port Channel) to the distribution switches.
Correct because VPC allows both uplinks to be active simultaneously, providing redundancy and load balancing without STP blocking.
- B
Enable STP on the access switches and set the root bridge priority to 0.
Why wrong: Incorrect because STP will block one of the uplinks to prevent loops, so only one link is active at a time, reducing redundancy.
- C
Configure the access switches with HSRP to the distribution switches.
Why wrong: Incorrect because HSRP is for first-hop redundancy for hosts, not for switch-to-switch uplink redundancy; it does not make both links active.
- D
Use static routing with equal-cost paths from the access switches to the distribution switches.
Why wrong: Incorrect because static routing does not prevent Layer 2 loops; if both links are in the same VLAN, a loop will occur without STP or VPC.
Quick Answer
The answer is to configure the access switches with vPC (Virtual Port Channel) to the distribution switches. This is correct because vPC allows each access switch to treat its two uplinks to the separate distribution switches as a single logical port channel, enabling active-active forwarding and eliminating the need for Spanning Tree Protocol to block one link. In a collapsed core design, this configuration ensures that if one distribution switch fails, the access switch can immediately reach the core through the surviving switch without any STP reconvergence or routing protocol changes, providing seamless failover. On the ENCOR 350-401 exam, this scenario tests your understanding of high-availability Layer 2 designs and the specific role of vPC in avoiding the classic trap of relying on HSRP or STP alone for failover in a collapsed core. A common memory tip is to think of vPC as “virtual pair cohesion”—the two distribution switches act as one logical switch, so the access switch never has to choose a path.
350-401 Enterprise Network Design Practice Question
This 350-401 practice question tests your understanding of enterprise network design. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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 campus network uses a collapsed core design with two distribution switches and multiple access switches. The engineer wants to ensure that if one distribution switch fails, the access switches can still reach the core. The access switches are connected to both distribution switches. What additional configuration is required on the access switches?
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
Configure the access switches with VPC (Virtual Port Channel) to the distribution switches.
Option A is correct because VPC allows the access switches to form a single logical link to the pair of distribution switches, enabling active-active forwarding and seamless failover. If one distribution switch fails, the access switch continues to reach the core through the surviving distribution switch without requiring STP convergence or routing protocol changes.
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.
- ✓
Configure the access switches with VPC (Virtual Port Channel) to the distribution switches.
Why this is correct
Correct because VPC allows both uplinks to be active simultaneously, providing redundancy and load balancing without STP blocking.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Enable STP on the access switches and set the root bridge priority to 0.
Why it's wrong here
Incorrect because STP will block one of the uplinks to prevent loops, so only one link is active at a time, reducing redundancy.
- ✗
Configure the access switches with HSRP to the distribution switches.
Why it's wrong here
Incorrect because HSRP is for first-hop redundancy for hosts, not for switch-to-switch uplink redundancy; it does not make both links active.
- ✗
Use static routing with equal-cost paths from the access switches to the distribution switches.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the misconception that STP or FHRP alone can solve distribution switch failure scenarios, but the key is that VPC provides active-active Layer 2 uplinks with fast failover, whereas STP blocks one link and FHRP only handles gateway redundancy, not uplink connectivity.
Detailed technical explanation
How to think about this question
VPC (Virtual Port Channel) allows two distribution switches to appear as a single logical device to the access switch, using a control plane protocol (e.g., vPC keepalive and peer-link) to synchronize state and prevent loops. This eliminates the need for STP blocking and provides sub-second convergence on link or switch failure, which is critical for campus networks with high availability requirements. In real-world deployments, VPC also supports multi-chassis EtherChannel (MEC) and can be combined with HSRP on the distribution switches for complete gateway redundancy.
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.
- →
Enterprise Network Design — study guide chapter
Learn the concepts, then practise the questions
- →
Enterprise Network Design practice questions
Targeted practice on this topic area only
- →
All 350-401 questions
2,015 questions across all exam domains
- →
ENCOR 350-401 study guide
Full concept coverage aligned to exam objectives
- →
350-401 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related 350-401 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Architecture practice questions
Practise 350-401 questions linked to Architecture.
Enterprise Network Design practice questions
Practise 350-401 questions linked to Enterprise Network Design.
SD-Access Architecture practice questions
Practise 350-401 questions linked to SD-Access Architecture.
SD-WAN Architecture practice questions
Practise 350-401 questions linked to SD-WAN Architecture.
QoS Architecture practice questions
Practise 350-401 questions linked to QoS Architecture.
Virtualization practice questions
Practise 350-401 questions linked to Virtualization.
Network Function Virtualization practice questions
Practise 350-401 questions linked to Network Function Virtualization.
Virtual Machines and Hypervisors practice questions
Practise 350-401 questions linked to Virtual Machines and Hypervisors.
VRF and Path Isolation practice questions
Practise 350-401 questions linked to VRF and Path Isolation.
Infrastructure practice questions
Practise 350-401 questions linked to Infrastructure.
OSPF practice questions
Practise 350-401 questions linked to OSPF.
BGP practice questions
Practise 350-401 questions linked to BGP.
Practice this exam
Start a free 350-401 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 350-401 question test?
Enterprise Network Design — This question tests Enterprise Network Design — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Configure the access switches with VPC (Virtual Port Channel) to the distribution switches. — Option A is correct because VPC allows the access switches to form a single logical link to the pair of distribution switches, enabling active-active forwarding and seamless failover. If one distribution switch fails, the access switch continues to reach the core through the surviving distribution switch without requiring STP convergence or routing protocol changes.
What should I do if I get this 350-401 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 →
Last reviewed: Jun 24, 2026
This 350-401 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 350-401 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.