Evaluating WAN Technology for OPEX Reduction
Short answer
A DMVPN over L3VPN provides the necessary scalability and OPEX efficiency for an in-house managed WAN upgrade.
Question
Key Takeaways
The core trap is confusing CAPEX (equipment) with OPEX (licensing/subscriptions) and misinterpreting 'in-house' as excluding modern technologies like SD-WAN or DMVPN, when it simply excludes managed services.
This question tests the ability to select a WAN technology that meets specific business goals of scalability and OPEX reduction while maintaining an in-house management model. It establishes how to interpret cost structures and licensing models in network design scenarios.
Common mistake: Many learners choose Managed SD-WAN because they associate 'OPEX reduction' with subscription-based managed services, ignoring the explicit requirement for an 'in-house' solution.
Expert Analysis
Why the Answer Is Correct
Option A (DMVPN over L3VPN) is the correct choice because it aligns with all three constraints: it supports exponential growth through dynamic spoke-to-spoke routing, allows for an in-house deployment model, and offers significant OPEX savings compared to legacy MPLS. The table provided in the exhibit shows that while DMVPN has higher initial costs, its long-term operational costs are lower than the other options, directly addressing the CTO's primary goal.
Why the Other Options Are Wrong
Option B (Managed SD-WAN) is incorrect because the requirement for an 'in-house solution' explicitly rules out third-party managed services. Option C (SD-WAN over L3VPN) is more expensive in terms of recurring license fees according to the exhibit, making it less optimal for strict OPEX reduction. Option D (SD-WAN over L2VPN) is not only costlier but also lacks the scalability and ease of branch activation provided by Layer 3 solutions.
Community Comment Notes
Community consensus was split, with many voting for Managed SD-WAN due to the 'OPEX' keyword. However, users who focused on the 'in-house' constraint correctly identified that managed services are excluded. Some users argued that licenses are OPEX, which is true, but failed to account for the fact that DMVPN can be deployed with perpetual licenses or lower recurring costs depending on the specific vendor model presented in the exhibit. The key differentiator remains the balance of total cost of ownership against the management model.
Exam Strategy
Always read the entire prompt for constraints before evaluating options. In this case, 'in-house' eliminates managed services, and 'OPEX reduction' requires analyzing the long-term cost trends, not just the initial price tag.
Frequently Asked Questions
Why is Managed SD-WAN incorrect if it reduces OPEX?
Are software licenses considered CAPEX or OPEX?
Community Votes
47% of anonymous learners picked answer A. Votes are pick records left by other test-takers — they are not the verified answer.
Discussion 9 contributions
Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.
From public community threads 9
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Doobiedoo 👍 5 Answered AThe answer to this question really hinges on if the Licenses are perpetual (Single-Use = CAPEX) or if they are subscriptions (Recurring = OPEX). I'm going to assume we're using Cisco licensing in this example so they will be subscription-based licenses and therefore considered OPEX. Since none of the requirements for the WAN are only met with SDWAN, DMVPN is still an option, especially since Cisco SDWAN typically uses subscription licensing based on circuit bandwidth. In that case, the answer is A. DMVPN over L3VPN
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xz_sky 👍 3 Answered DConsider licenses cost is CAPEX
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cisco_guy 👍 2 Answered CIn the question it states "in-house", which means they're not going to go with anything managed, therefore B is not the solution. There's growth expected and based on the question, they are looking for SD-WAN features.
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Rollizo 👍 2 Answered BShould be B: main goal is OPEX reduction
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JCGO 👍 1 Answered Dleast opex - eiminates first 2 options. in-house ("done within an organization or business by its employees rather than by other people") eliminates 3rd option. So answer is clearly D.
Show 4 more comments
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The1BelowAll 👍 1 Answered AFor OPEX count the number of $, DMVPN over L3 has less for License and WAN.
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PeterCheng 👍 1 Answered AB should be CAPEX reduction, not OPEX reduction.So A is the answer.
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Seawanderer 👍 1 Answered BEquipment and licenses are capex
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anonymousch 👍 1 Answered DISP + Licenses costs are OPEX.
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