JNCDS-DC
Juniper Networks Certified Design Specialist, Data Center (JNCDS-DC)
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Cheat sheet
Keep the key ideas within reach.
ExploreKey terms
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ExploreStudy plan
Give each week a clear focus.
ExploreCommon mistakes
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ExploreCase studies
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ExploreExam-day guide
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ExploreAbout this exam
The JNCDS-DC is a Juniper Networks data center design certification, and this page is an independent study resource for candidates preparing for it. Juniper's certification pages now sit within the HPE networking portfolio, alongside Juniper QFX Series Switches, Juniper PTX Series Routers, Juniper SRX Series Firewalls, and Apstra Data Center Director - the product families whose design concepts the credential is built around. The exam is intended for network design engineers, data center architects, and senior operations staff who plan fabrics rather than merely configure them, so expect scenario-based items that ask you to choose between competing designs and justify the trade-offs. Coverage follows five design domains: architecture and design principles; switching and fabric technologies; routing and IP fabric design; security and network services; and automation, orchestration, and management. Preparation should combine vendor design documentation and validated design guides with hands-on lab work in a virtual topology, so that EVPN-VXLAN, IP fabric underlay and overlay behavior, and intent-based automation are familiar in practice and not just on paper. Important: the official JNCDS-DC certification page returned a 404 error when checked on 2026-11-06, so the exam's item count, time limit, passing score, fee, format, retake policy, validity period, and domain weightings could not be verified and are not published here. Confirm all of those against the current official Juniper/HPE certification source before you book or schedule study time.
What you'll study
About JNCDS-DC preparation
Is this an official Juniper or HPE study page?
No. This is independent study material and is not affiliated with, endorsed by, or sponsored by Juniper Networks or HPE. Product and certification names are used only to describe what the exam covers. Always treat the official certification track page as the authoritative source for exam logistics and current objectives.
How many questions are on the exam and how long do I get?
We cannot state this. The official JNCDS-DC track page returned HTTP 404 when retrieved on 2026-11-06, so item count and time limit are unverified. Do not rely on figures quoted in forums or older blog posts, since exams are revised. Check the current official Juniper/HPE certification page before scheduling.
What is the passing score and what does the exam cost?
Unverified. Neither the passing score nor the exam fee appears in any source we could retrieve, because the certification page was unavailable. Both values change over time and by region, so confirm them on the official certification site at the moment you register rather than budgeting from secondhand numbers.
What format is the exam - multiple choice or design scenarios?
The format could not be confirmed from the source. Design-track exams commonly mix multiple-choice items with scenario-based questions that present requirements and ask for the best design, but treat that as expectation, not fact. Verify the stated format on the official page, and prepare for scenario reasoning either way.
If I fail, how soon can I retake it, and how long is the certification valid?
Unknown from available sources. Retake waiting periods and certification validity periods are set by the vendor and are revised periodically. Because the official page was unreachable on 2026-11-06, we publish no figure. Confirm both policies on the official certification site before your first attempt so you can plan a retake window.
Which topics should I study first?
Start with architecture and design principles, because the other four domains assume you can reason about oversubscription, failure domains, and scale. Then move to switching and fabric technologies, followed by routing and IP fabric design. Security and network services and automation come last, since they build on a working understanding of the fabric.
How much weight does each domain carry?
We cannot confirm the weightings. The five domains we describe - architecture, switching and fabric, routing and IP fabric, security and services, and automation and management - reflect the exam's published scope, but the percentage allocated to each is unverified because the official page was unavailable. Check the current objectives document for authoritative weights.
What are the most common reasons candidates fail a design exam?
Two patterns dominate. First, memorizing configuration syntax instead of learning why a design is chosen, which collapses on scenario items with competing trade-offs. Second, skipping hands-on validation, so the candidate cannot predict how an EVPN-VXLAN overlay or an IP fabric underlay actually behaves under failure. Lab the designs you read about.
How should I prepare in the final two weeks?
Work backward from weak domains rather than rereading everything. Build one complete reference design end to end - underlay, overlay, security insertion, and automation - and defend each choice aloud. Then practice explaining why the rejected alternatives are worse. Design exams reward structured justification more than recall of command syntax.
Where do I confirm the exam details before booking?
Use the official Juniper/HPE certification and training site. The Juniper track URL for JNCDS-DC returned a 404 on 2026-11-06, so navigate from the vendor's certification landing page or the HPE certification-learning portal instead of a saved bookmark, and re-check every parameter before you pay.