50 Cisco Certified DevNet Associate Practice Questions: Question Bank 2025

A script calls a REST API and receives an HTTP 401 response. The endpoint URL is correct and reachable. What is the most likely cause?

You are troubleshooting a Python virtual environment issue where your script imports a module successfully on your laptop but fails in a CI pipeline with "ModuleNotFoundError". Which best practice most directly prevents this?

An application needs to send the same event to multiple independent consumers, and each consumer must receive its own copy of every event. Which messaging pattern is most appropriate?

A network engineer wants to retrieve structured data from a network device using an API designed for configuration and operational state using a standard data modeling approach. Which API style best fits?

A developer is designing a REST API client that must safely retry requests when transient errors occur. Which HTTP method is generally safest to automatically retry because it is idempotent?

An application deployed in containers needs to store API keys securely without baking them into the image or committing them to source control. Which approach is the best practice?

A network automation script uses NETCONF to apply configuration changes. You want to ensure the device validates the candidate configuration before it becomes active and allow an atomic commit. Which NETCONF capability/workflow should you use?

A developer receives an API response body as JSON and needs to extract a nested value. Which statement best describes why using a JSON parser library is preferred over searching with regular expressions?

You are building an integration that triggers workflows based on network events from multiple devices. Events may be delivered more than once, and delivery order is not guaranteed. Which design approach best ensures correct processing?

A developer calls a REST API endpoint that creates a resource. The server creates the resource successfully but the client times out before receiving the response. The client retries the same request, and duplicate resources are created. Which API design change most effectively prevents duplicates while preserving reliability?

A Python script consumes a REST API. You need to send input data in the request body and ensure the server interprets it as JSON. Which HTTP header is most appropriate to include?

Your application must trigger an action on a Cisco platform only when a network event occurs (for example, a device status change) without continuously polling an API. Which approach is recommended?

You are troubleshooting a REST API call that returns HTTP 401. Which conclusion is most accurate?

A developer is refactoring code that interacts with multiple network devices. They want to ensure that the automation logic is separated from the device-specific transport details (REST vs SSH vs NETCONF) to improve maintainability. Which design approach best supports this goal?

You are writing an Ansible playbook to configure 200 switches. You must avoid changing configurations when the desired state is already present and provide accurate change reporting. Which Ansible principle enables this behavior?

A team is deploying a containerized microservice that calls multiple external APIs. They need to inject API tokens without rebuilding the container image and without storing secrets in source control. Which solution is the best practice?

You are troubleshooting an API integration. A GET request with the correct URL returns HTTP 406 Not Acceptable when you include the header 'Accept: application/xml'. The API documentation indicates it only supports JSON responses. What is the most likely fix?

A network automation script pushes configuration changes to devices. The team wants a safe way to validate the configuration syntax and potential impact before committing changes. Which approach best aligns with this requirement?

A developer uses OAuth 2.0 to access an API. The app is a backend service (no user interaction) and should not store user credentials. Which OAuth 2.0 grant type is most appropriate?

You receive telemetry from devices to a collector using UDP. Occasionally, the collector shows gaps in time-series data even though the device is generating measurements. Which explanation best fits this symptom?

A Python script parses a JSON API response and then fails with a KeyError when trying to access response['items'][0]['id']. The API sometimes returns an empty list for 'items'. What is the BEST way to prevent the runtime error while keeping the code readable?

You are integrating with a REST API and receive an HTTP 401 response to a request that previously worked. Which action is MOST appropriate to take first?

You need to clone an existing Git repository, create a new feature branch, and push it to the remote origin. Which sequence of commands accomplishes this?

A client application must call an API that enforces rate limits. Which design choice BEST reduces the chance of exceeding the limit while still providing responsive behavior?

Your organization uses infrastructure-as-code for network device configuration. A new playbook accidentally changes production settings when tested. What is the BEST practice to prevent unreviewed changes from being applied to production?

A developer is troubleshooting why a REST API call is failing. The API requires a JSON body, but the server returns HTTP 415 Unsupported Media Type. What is the MOST likely cause?

A containerized web service is deployed to a Kubernetes cluster. You must ensure traffic is only sent to pods that have successfully started and can serve requests. Which Kubernetes feature should you use?

You are implementing a webhook receiver for a CI system that triggers network automation. The system must ensure the webhook request genuinely came from the CI provider and was not spoofed. What is the BEST approach?

A Python automation script authenticates to a Cisco platform API using OAuth 2.0. The script works initially but fails later without code changes. The token endpoint is reachable, and client credentials are unchanged. The API returns 401 to normal requests. What is the MOST likely explanation?

You must design a network automation workflow that configures 500 devices and provides a report of success/failure per device. A single device failure must not stop the entire run, and the run should be restartable without reconfiguring devices already completed. Which approach BEST meets these requirements?

A developer is consuming an API that sometimes returns large datasets. The API provider supports pagination. Which approach is the best practice to reduce memory usage and improve responsiveness in the client application?

An application must call an external REST API that enforces rate limits and returns HTTP 429 responses when limits are exceeded. Which client behavior is recommended?

A developer is troubleshooting a Python script that calls a REST endpoint but receives an HTTP 415 Unsupported Media Type error when sending JSON data. What is the most likely fix?

You are asked to describe the role of a CI/CD pipeline in application delivery. Which statement is most accurate?

A network automation engineer is writing an Ansible playbook to gather facts from Cisco devices. Which inventory variable is most appropriate to ensure Ansible uses the correct network CLI transport?

A developer is designing a microservice that needs to store configuration values (API base URL, timeouts) that differ by environment (dev/test/prod). Which approach is recommended?

You are integrating with a REST API that uses OAuth 2.0. The API requires a bearer token on each request. Where should the token be placed?

A containerized application intermittently fails because it cannot resolve a dependent service hostname inside the cluster. Basic connectivity works when using IP addresses. Which is the most likely root cause?

A team is creating a network automation workflow that makes changes across hundreds of devices. They must ensure the change is either applied everywhere or rolled back to the previous state if any device fails mid-way. Which design pattern best fits this requirement?

An enterprise exposes an internal API through an API gateway. The security team requires the solution to protect against excessive requests from a single client, while still allowing legitimate burst traffic within defined limits. Which gateway capability best addresses this requirement?

You are writing a Python script that will call a REST API and then pass the response to another function for processing. Which approach is the best practice to make your code easier to test and maintain?

A REST API returns an HTTP 409 Conflict when your application attempts to create a resource that already exists. Which client behavior is most appropriate?

You need to integrate two applications using an event-driven approach so the producer does not need to know which consumers exist. Which pattern best fits this requirement?

A Cisco DNA Center API call succeeds when tested in Postman, but your automation script intermittently fails with a timeout when run in a pipeline. Which change is most likely to improve reliability?

You are debugging a REST API integration. The server responds with HTTP 415 Unsupported Media Type when you send JSON in the body. What is the most likely issue?

A team is deploying a containerized microservice that calls multiple Cisco platform APIs. They want to avoid storing long-lived credentials in the container image. Which approach is the best practice?

You are automating configuration changes across 200 network devices. You need idempotent behavior and clear separation between desired state and execution. Which tool choice best aligns with this requirement?

A NetDevOps pipeline runs tests against a lab network after every commit. You want a fast, deterministic test that verifies basic L3 reachability without depending on external DNS or internet access. Which test is most appropriate?

You are building a webhook receiver to process events from a Cisco platform. The receiver must verify that incoming requests are authentic and have not been modified in transit. Which design is most appropriate?

A Python client uses a Cisco REST API that returns results in pages using a "next" link in the response. The developer instead increments an offset parameter until a request returns an empty list, but sometimes misses items when the dataset changes during retrieval. What is the best fix?