An all-reduce that used to take seconds now takes minutes, and the training team says the network is slow. On an InfiniBand fabric you might start with ibdiagnet, or with UFM's health view; on Spectrum-X you might reach for What Just Happened or NetQ. NVIDIA's NCP-AIN study guide is full of decisions like that one. Its troubleshooting area names the commands outright (ib_write_lat, ib_write_bw, ibping, ibstat, ibdiagnet, ibnodes, iblinkinfo and cl-resource-query), and its automation area expects NVUE templates and Ansible playbooks.
A good NCP-AIN practice test therefore makes you pick a tool for a symptom and predict what it will show, across both fabrics the exam covers.
Questions that test tool choice and configuration
These three follow objectives from the Spectrum-X, InfiniBand and troubleshooting areas of the study guide.
Three NCP-AIN-style questions
RoCE traffic between GPU servers on a Spectrum-X fabric drops packets during all-reduce bursts. Which configuration makes the RoCE traffic class lossless and signals congestion before switch buffers overflow?
RoCE needs a lossless traffic class. PFC pauses the RoCE priority when a queue fills instead of dropping its packets, and ECN marks packets as queues build so the senders reduce their rate before PFC has to pause anything. A larger MTU changes the overhead per packet but does nothing about drops. Turning QoS off removes the separation that lets RoCE be treated as lossless. TCP is a different transport and gives up RDMA altogether.
A node's training job cannot reach the InfiniBand fabric. You want to know whether the node's own HCA port is up and at what rate it linked. Which command shows that?
ibstat reports the local HCA's ports, including their state, physical state and link rate. ibping tests whether another port answers and needs a responder on the far end. ib_write_bw measures RDMA bandwidth between two nodes, which assumes the link already works. ibdiagnet scans the whole fabric for errors, which is more than one port's status calls for.
Two tenants share one InfiniBand fabric, and their nodes must not be able to communicate with each other. What provides that isolation?
Partitions, identified by PKeys, are InfiniBand's mechanism for multi-tenant isolation: ports communicate only with members of a partition they share. VLANs belong to Ethernet. MTU sets packet size, and adaptive routing chooses paths through the fabric; neither keeps tenants apart.
Full NCP-AIN set: 7 timed exams, every answer explained, $19.99 one-time.
See the practice testsIf you got question 2 wrong, practice that family of tools first. The study guide lists seven InfiniBand diagnostic commands in a single objective, and questions can turn on the difference between checking one port, testing a path and scanning the fabric.
Try 15 NCP-AIN practice questions free
They come from the NCP-AIN practice tests, and each option shows its explanation once you answer.
- 7 timed practice exams
- Every answer explained
- A score for each domain
- $19.99 one-time
Matching the exam's pace
As of October 2026, NVIDIA lists 70 to 75 questions in 120 minutes for NCP-AIN, which works out to about 100 seconds a question. Our NCP-AIN practice tests have 60 questions each and allow the same 120 minutes, which is a slower pace than the real exam. To rehearse the real one, give yourself 100 minutes per test.
Practicing on equipment you don't have
Few candidates have a spare Spectrum-X fabric or InfiniBand cluster. For the Ethernet side the study guide itself points to a simulator: objective 2.4 asks you to use NVIDIA Air to simulate network environments and identify potential issues. NVIDIA now calls it DSX Air, and its page lists Spectrum-X Ethernet switches, ConnectX SuperNICs, BlueField DPUs and NetQ among what it simulates, with a free trial as of October 2026. That covers much of the Ethernet side of the exam, such as switch configuration and NetQ monitoring.
The same page does not list InfiniBand, so for the InfiniBand half the official route is NVIDIA's self-paced courses. InfiniBand Essentials introduces the technology, and NVIDIA describes InfiniBand Network Administration as covering "both theoretical and practical aspects." If you have access to any InfiniBand hardware at work, even a pair of nodes on one switch, running ibstat, iblinkinfo and ib_write_bw there gives you real output to compare with the questions.
NCP-AIN practice options in 2026
| Option | What it covers | What it leaves out |
|---|---|---|
| NVIDIA's NCP-AIN study guide (free, linked from the certification page) | Every objective, with the commands and tools it expects | Questions to practice on |
| NVIDIA's InfiniBand Essentials, InfiniBand Network Administration and Cumulus Linux Essentials courses | The training NVIDIA recommends for this exam, self-paced | A practice exam: as of October 2026 the certification page lists none |
| NVIDIA DSX Air (sign-up) | Hands-on Spectrum-X, SuperNIC, BlueField and NetQ work in simulation; free trial as of October 2026 | InfiniBand, which its page does not list |
| preporato.com NCP-AIN practice tests | Seven timed tests of 60 questions across all six areas of the study guide, an explanation for every option, a score for each exam area | Hands-on work: we have no networking labs for NCP-AIN |
We write the preporato.com tests, so read our row with that in mind. The free questions on the certificate page are drawn from the same tests, which lets you check the question style and the explanations before paying.
One way to divide the work: the question bank for the written material, DSX Air for the Ethernet side, and whatever InfiniBand access you can get for the commands. The 6-week NCP-AIN study plan lays out the weeks, and the NCP-AIN cheat sheet collects the commands in one place.
Frequently asked questions
Does NVIDIA offer an official NCP-AIN practice exam?
As of October 2026, NVIDIA's NCP-AIN certification page lists a study guide and three self-paced courses (InfiniBand Essentials, InfiniBand Network Administration and Cumulus Linux Essentials), and no practice exam.
Is NCP-AIN more about Spectrum-X Ethernet or InfiniBand?
Both, equally. The study guide gives the Spectrum networking area and the InfiniBand networking area the same weight, and together they make up most of the exam. The troubleshooting area draws on both fabrics as well.
Can I practice NCP-AIN for free?
Partly. NVIDIA's study guide is free, DSX Air offers a free trial as of October 2026, and the certificate page has free NCP-AIN practice questions with explanations. The NCP-AIN practice questions article explains 12 more.
How many practice tests should I take before booking NCP-AIN?
Keep going until two tests you have not seen before both score 80% or higher at the 100-minute pace. NVIDIA's certification page does not state a passing score (as of October 2026), so we aim well above any plausible pass mark.