Best Cisco DCAI 300-640 practice exams in 2026 (an honest look)
The short version: there isn't much yet, and most of what you'll find is dumps. No Boson ExSim, no Pearson practice test, no big-name course. What does exist: Cisco's own DCAIE learning path on Cisco U (the recommended prep), a five-day instructor-led DCAI course at about $4,395, a handful of no-name Udemy question sets, and CrushCert, which has the only hands-on NX-OS labs for the lossless-fabric configuration the exam is really about.
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We build DCAI prep ourselves, so weigh our own entry accordingly. The rest is an honest account of what exists for the Implementing Cisco Data Center AI Infrastructure (300-640 DCAI) exam in late 2026, which isn't a long list.
What the exam actually is
| What | Detail |
|---|---|
| Exam code | 300-640 DCAI |
| Time | 90 minutes |
| Cost (USD) | $300 |
| Questions / pass score | Not published by Cisco |
| Earns | Cisco Certified Specialist – Data Center AI Infrastructure |
| Also counts as | CCNP Data Center concentration (with 350-601 DCCOR) |
| Domain | Weight |
|---|---|
| AI fundamentals and applications | 20% |
| AI infrastructure components and architecture | 30% |
| AI infrastructure deployment and data management | 30% |
| AI infrastructure operations and troubleshooting | 20% |
Sixty percent of the exam is architecture and deployment: GPU-cluster network design, lossless Ethernet for RoCEv2 (PFC, ECN, ETS, DCQCN), Nexus 9000 QoS, UCS compute and storage for AI, and the management plane (Intersight, Nexus Dashboard, Hyperfabric AI). That's the part no multiple-choice set teaches on its own.
Quick comparison
| Resource | Best for | Price (approx.) |
|---|---|---|
| Cisco U — DCAIE learning path | Official, structured prep | Cisco U subscription |
| DCAI 5-day course (Learning Partner) | Employer-funded, instructor-led | ~$4,395 / 44 CLC |
| CrushCert | Adaptive questions + NX-OS CLI labs | $15–24 / mo |
| Udemy practice sets | Cheap third source | ~$15–20 on sale |
| Cisco design guides & docs | The source material | Free |
1. Cisco U — the DCAIE learning path
OFFICIAL PREPCisco names AI Solutions on Cisco Infrastructure Essentials (DCAIE) as the preparation path for 300-640, with Operate and Troubleshoot AI Solutions on Cisco Infrastructure (DCAIAOT) as the supplement. DCAIE is about 34 hours on Cisco U and is included in the paid Cisco U tiers; Cisco has also opened it for free during "Rev Up to Recert" promotions (it ran free in early 2025 and earned 34 CE credits), so check the Learning Network before paying. It is the closest thing to a syllabus for an exam Cisco otherwise documents thinly.
Best for: anyone who already has Cisco U through work, and anyone who wants to be sure they've covered what Cisco thinks matters. Trade-off: it's a course, not a question bank, and the built-in checks are light.
2. The five-day DCAI course
INSTRUCTOR-LEDCisco Learning Partners (Fast Lane, Global Knowledge, Sunset Learning and others) run the official Implementing Cisco Data Center AI Infrastructure course: five days, about $4,395 in the US or 44 Cisco Learning Credits, online or in a classroom. The outline is the exam blueprint expanded — AI fundamentals, fabric design and transport, building lossless fabrics, compute and storage, cluster setup including a RAG deployment, operations and troubleshooting — with labs on real gear.
Best for: people whose employer has Learning Credits to burn and want hands-on time on Nexus and UCS before the exam. Trade-off: the price. Nobody should pay this out of pocket for a $300 exam.
3. CrushCert
LABS + ADAPTIVEThat's us. CrushCert pairs an adaptive 300-640 bank (100 original questions weighted 20/30/30/20 like the blueprint, every answer explained, reviewed against Cisco's Nexus 9000 and Intersight documentation) with seven hands-on labs: match the lossless-Ethernet toolkit (PFC, ECN, ETS, RoCEv2, DCQCN, PFC watchdog) to what each piece does, place AI workloads on the right infrastructure, match Intersight / NDFC / APIC / Nexus Dashboard Insights / Hyperfabric AI to their jobs, a troubleshooting ticket where a new leaf on default QoS is dropping RoCE traffic, and three NX-OS CLI labs where you type the real config: the full RoCEv2 QoS chain (class-map → policy-map → network-qos with PFC → system qos → interface), the ECN/WRED queuing policy, and a troubleshoot where one GPU port is missing its PFC settings. Timed mock exams run 90 minutes with a pass line set high (80%) because Cisco doesn't publish the real one. $15/mo for this exam, or $24/mo for the Professional plan, which also covers DCCOR and the other CCNP exams.
Best for: the 60% of the exam that is architecture and deployment, where typing the config once beats reading about it three times. Trade-off: 100 questions is a focused bank, not an exhaustive one, and a subscription suits a few weeks of steady study. Here's CrushCert's DCAI prep.
4. Udemy practice sets
Udemy lists several 300-640 practice-test courses at $15–20 on sale. None is from an instructor with a track record on Cisco data center exams, and the question quality we've seen ranges from fine to generic. If you use one, treat it as a third source, check that the questions are written to the 300-640 topics (not generic "AI in the data center" trivia), and ignore any that promise "real exam questions" — that's a dump with a Udemy wrapper.
5. Cisco's own documentation (free)
For this exam the source material is unusually good. The Cisco Data Center Networking Blueprint for AI/ML Applications white paper, the Nexus 9000 QoS configuration guide (the PFC/ECN/queuing chapters), the Nexus Dashboard and Intersight overviews, and the UCS AI server datasheets cover most of the architecture and deployment domains directly. The 300-640 exam topics PDF is your checklist; read it against those documents and you've built your own course.
Our honest recommendation
Work from the exam topics PDF and Cisco's AI/ML networking documents; take DCAIE on Cisco U if you have access. Drill the config with hands-on NX-OS labs until the RoCEv2 QoS chain is muscle memory (where CrushCert fits), then run timed mocks and book when you're consistently at 85%. Skip the dumps, and skip the five-day course unless someone else is paying. For how long all that takes, see how long to study for Cisco DCAI, or go straight to the 3-week and 6-week study plan.
Try the labs + adaptive piece free
Adaptive 300-640 quizzes, seven hands-on labs including three NX-OS CLI labs, and 90-minute timed mock exams — 7-day free trial, no card required.
See CrushCert's DCAI prep →Frequently asked questions
Is there a Boson ExSim for the Cisco DCAI 300-640 exam?
Not as of November 2026. Boson has not published an ExSim-Max for 300-640, and none of the established Cisco practice-test publishers have a DCAI product yet. The options are Cisco's own DCAIE learning path on Cisco U, the five-day instructor-led DCAI course, no-name Udemy practice sets, and CrushCert's adaptive bank with NX-OS CLI labs.
What is the best way to study for Cisco DCAI?
Work from Cisco's official 300-640 exam topics and the Nexus 9000 AI/ML networking design documents, use the DCAIE learning path on Cisco U if you have access, and practice the lossless-Ethernet configuration (PFC, ECN, QoS for RoCEv2) until you can type it from memory. Then drill scenario questions and aim for 85% or better on timed practice, because Cisco does not publish the passing score.
How many questions are on the DCAI exam?
Cisco does not publish the question count or passing score for 300-640. The exam is 90 minutes and costs $300. Third-party sites that quote a specific count or an 825 cut score are guessing; plan for 55 to 65 questions, like other Cisco concentration exams, and aim well above a bare pass.
Are 300-640 exam dumps safe to use?
No. Most of what comes up when you search for DCAI practice tests is dump sites selling leaked questions. Using them violates the Cisco Certification and Confidentiality Agreement and can get every Cisco certification you hold revoked. Use legitimate practice with explanations instead.