- A
Deploy SD-WAN to actively use both links with policy-based load balancing.
Correct because SD-WAN is designed to utilize multiple WAN links simultaneously, providing load balancing and failover based on application policies.
- B
Configure static routes with different metrics for each link and use HSRP for failover.
Why wrong: Incorrect because static routes with different metrics provide only active/passive failover, not active/active load balancing; HSRP is for LAN redundancy, not WAN.
- C
Use BGP with both ISPs and rely on BGP best path selection for load balancing.
Why wrong: Incorrect because BGP does not load balance by default; it selects a single best path unless multipath is configured, and it may not provide per-packet load balancing easily.
- D
Implement a VPN tunnel between the branch and headquarters using only one link.
Why wrong: Incorrect because this uses only one link, not both, and does not provide load balancing or bandwidth aggregation.
Quick Answer
The answer is to deploy SD-WAN with active/active load balancing over multiple ISP links. This is correct because SD-WAN natively supports policy-based load balancing, allowing both WAN connections to be used simultaneously for bandwidth aggregation while dynamically distributing traffic based on application policies, SLA metrics, or link utilization. Unlike traditional designs that rely on a single active link with passive failover, SD-WAN provides seamless failover by rerouting traffic in real time if one ISP link degrades or fails, meeting the high availability and bandwidth aggregation requirements. On the ENCOR 350-401 exam, this concept tests your understanding of SD-WAN’s control-plane and data-plane separation, often appearing in scenario-based questions where a trap is to choose BGP with unequal-cost load balancing or a dual-router design without policy control. Remember the mnemonic “Two Links, One Brain” — SD-WAN treats multiple ISPs as a single intelligent fabric, not separate active/passive paths.
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 network engineer is designing a WAN connection for a branch office that requires high availability and bandwidth aggregation. The branch has two internet connections from different ISPs. The engineer wants to use both links actively for load balancing and failover. Which design approach should be used?
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
Deploy SD-WAN to actively use both links with policy-based load balancing.
SD-WAN is the correct design because it natively supports active/active utilization of multiple WAN links with policy-based load balancing, allowing traffic to be distributed across both ISP connections based on application policies, SLA metrics, or other criteria. It also provides seamless failover by dynamically rerouting traffic if one link fails, meeting the requirements for high availability and bandwidth aggregation without relying on a single active link.
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.
- ✓
Deploy SD-WAN to actively use both links with policy-based load balancing.
Why this is correct
Correct because SD-WAN is designed to utilize multiple WAN links simultaneously, providing load balancing and failover based on application policies.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Configure static routes with different metrics for each link and use HSRP for failover.
Why it's wrong here
Incorrect because static routes with different metrics provide only active/passive failover, not active/active load balancing; HSRP is for LAN redundancy, not WAN.
- ✗
Use BGP with both ISPs and rely on BGP best path selection for load balancing.
Why it's wrong here
Incorrect because BGP does not load balance by default; it selects a single best path unless multipath is configured, and it may not provide per-packet load balancing easily.
- ✗
Implement a VPN tunnel between the branch and headquarters using only one link.
Why it's wrong here
Incorrect because this uses only one link, not both, and does not provide load balancing or bandwidth aggregation.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the misconception that BGP multipath or static routes with HSRP can achieve active/active load balancing, but these methods either require complex tuning or are inherently active/passive, failing to meet the policy-based and application-aware requirements that SD-WAN uniquely addresses.
Detailed technical explanation
How to think about this question
SD-WAN uses a centralized controller (e.g., vManage) to distribute flow-based forwarding rules to edge devices, enabling per-packet or per-flow load balancing across multiple transports. It can also measure real-time loss, latency, and jitter to dynamically steer traffic, which is critical for voice/video over WAN links with varying quality. In contrast, traditional routing protocols like BGP require complex multipath configurations (e.g., maximum-paths, bgp bestpath tie-break) and cannot enforce application-specific policies without additional overlay mechanisms.
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: Deploy SD-WAN to actively use both links with policy-based load balancing. — SD-WAN is the correct design because it natively supports active/active utilization of multiple WAN links with policy-based load balancing, allowing traffic to be distributed across both ISP connections based on application policies, SLA metrics, or other criteria. It also provides seamless failover by dynamically rerouting traffic if one link fails, meeting the requirements for high availability and bandwidth aggregation without relying on a single active link.
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.