200-901 Practice Test 30 — 15 Questions

Question 1

Which API is used to execute CLI commands on Cisco IOS XE devices using on-device programmability?

Accepted Answer

RESTCONF. RESTCONF is a RESTful API that uses HTTP methods to access structured data defined in YANG models, and on Cisco IOS XE devices, it can be used to execute CLI commands via the 'cli' YANG data model. This allows programmatic execution of CLI commands without requiring an interactive SSH session, making it the correct choice for on-device programmability.

Answer

DNA Center API

Answer

Meraki Dashboard API

Answer

Webex API

Question 2

Which THREE of the following are common stages in a continuous integration pipeline? (Select THREE)

Accepted Answer

Build. The build stage (C) is a core step in a continuous integration pipeline where source code is compiled, dependencies are resolved, and executable artifacts are produced. Without a successful build, subsequent stages like testing and deployment cannot proceed, making it a foundational stage in CI/CD workflows.

Answer

Monitor

Answer

Deploy

Question 3

In DNA Center, which API category is used to deploy templates to devices?

Accepted Answer

Change your network. The 'Change your network' API category in Cisco DNA Center is specifically designed for network configuration and provisioning tasks, including deploying templates to devices. This category encompasses APIs that push configuration changes, such as applying CLI templates via the Template Programmer (formerly Template Editor) or provisioning new network settings, directly aligning with the action of deploying templates to network devices.

Answer

Platform

Answer

Know your network

Answer

Run your network

Question 4

A developer is implementing error handling in a script that makes multiple API calls to Cisco ACI. Which approach is best practice for handling transient network failures?

Accepted Answer

Retry with exponential backoff. Exponential backoff is the best practice for handling transient network failures in API calls because it reduces server load and prevents thundering herd problems. Cisco ACI's REST API can become overwhelmed if many clients retry simultaneously with fixed delays, making exponential backoff the recommended approach in REST API design and Cisco's own documentation.

Answer

Retry with fixed delay

Answer

Ignore errors and continue

Answer

Always retry immediately

Question 5

In Python, which keyword is used to define a function that does not return any value?

Accepted Answer

def. In Python, the `def` keyword is used to define any function, regardless of whether it returns a value. A function that does not explicitly return a value automatically returns `None`. The `def` keyword is the correct answer because it is the fundamental syntax for function definition, and the question asks for the keyword used to define the function itself, not the mechanism for returning or omitting a value.

Answer

pass

Answer

yield

Answer

return

Question 6

Which of the following best describes the purpose of a unit test in software development?

Accepted Answer

To test individual functions or methods in isolation. Unit tests focus on verifying the correctness of the smallest testable parts of an application, such as individual functions or methods, in complete isolation from dependencies (e.g., using mocks or stubs). This ensures that each unit of code behaves as expected under controlled conditions, which is a foundational practice in test-driven development (TDD) and continuous integration pipelines. In the context of the 200-901 exam, understanding unit testing is critical for validating code quality in Cisco platforms like Cisco DNA Center or Meraki API integrations.

Answer

To check the performance of the application under load

Answer

To verify that different modules work together correctly

Answer

To test the entire system from end to end

Question 7

A network engineer is troubleshooting an issue where hosts in VLAN 100 cannot reach a server at 10.1.1.100. The switch interfaces are configured as access ports in VLAN 100, and the default gateway is 10.1.1.1. The engineer checks the switch and finds that the ARP table does not contain the server's MAC address. Which two actions should the engineer take to resolve the issue? (Choose two.)

Accepted Answer

Check the ARP table on the default gateway router.. If the switch port connected to the server is not in VLAN 100, the server will be in a different broadcast domain and will not receive ARP requests from hosts in VLAN 100. This would cause the ARP table on the switch to lack the server's MAC address, as the switch cannot learn it through normal Layer 2 flooding within the VLAN.

Answer

Ping the server's IP address from the switch management interface.

Answer

Ping the default gateway from a host in VLAN 100.

Answer

Check the MAC address table on the switch for the server's MAC.

Question 8

A network engineer is designing a wireless network for an office that requires high throughput and minimal interference. Which two channels should be used for the 2.4 GHz band to avoid overlap? (Choose two.)

Accepted Answer

Channel 6. In the 2.4 GHz band, channels 1, 6, and 11 are the only non-overlapping channels when using 20 MHz channel spacing, as each channel occupies 22 MHz of bandwidth and these three are spaced 25 MHz apart. Channels 1 and 6 are correct because they do not overlap, minimizing co-channel interference and maximizing throughput.

Answer

Channel 11

Answer

Channel 9

Answer

Channel 3

Question 9

Which THREE of the following are best practices when using Git for a collaborative project? (Choose three.)

Accepted Answer

Use feature branches for new work.. A is correct because feature branches isolate new work from the stable main branch, enabling parallel development without disrupting the shared codebase. This practice aligns with Git's branching model and supports code review and continuous integration workflows.

Answer

Commit directly to the main branch.

Answer

Avoid pulling from remote to prevent conflicts.

Question 10

A Python script uses a list comprehension: [x**2 for x in range(20) if x % 2 == 0]. Which of the following is equivalent?

Accepted Answer

result = [] 
for x in range(20): 
    if x % 2 == 0: 
        result.append(x**2). It directly translates the list comprehension into an equivalent for-loop with a conditional append. The comprehension `[x**2 for x in range(20) if x % 2 == 0]` iterates over numbers 0–19, filters for even numbers (x % 2 == 0), squares each, and collects the results in a list. Option A's explicit loop and conditional produce the exact same sequence of appended values.

Answer

result = map(lambda x: x**2, filter(lambda x: x % 2 == 0, range(20)))

Answer

result = [] 
for x in range(20): 
    result.append(x**2)

Answer

result = [x**2 for x in range(20) if x % 2 != 0]

Question 11

A company uses GitHub Actions for CI/CD. They want to automatically scan dependencies for known vulnerabilities on every push. Which action should be added to the workflow?

Accepted Answer

Dependabot. Dependabot is the correct GitHub-native tool for automatically scanning dependencies for known vulnerabilities on every push. It monitors the dependency manifest files (e.g., package.json, requirements.txt) against the GitHub Advisory Database and opens pull requests to update vulnerable packages. This directly meets the requirement of scanning dependencies for known vulnerabilities in a CI/CD workflow.

Answer

CodeQL

Answer

ESLint

Answer

GitHub Secret Scanning

Question 12

Which Docker networking mode provides the most isolation by not connecting the container to any network?

Accepted Answer

none. The `none` networking mode in Docker creates a container with no network interfaces except the loopback device, providing the highest level of network isolation. This means the container cannot send or receive any external traffic, making it ideal for security-sensitive workloads that require complete network disconnection.

Answer

overlay

Answer

bridge

Answer

host

Question 13

An application needs to receive real-time notifications when a new message is posted in a Webex space. Which Webex API feature should be used?

Accepted Answer

Create a webhook that triggers on 'messages' events. Webex uses webhooks to push real-time event notifications to an external server. By creating a webhook that triggers on 'messages' events, the application receives an HTTP POST request whenever a new message is posted in the specified space, eliminating the need for polling or persistent connections.

Answer

Establish a WebSocket connection to the Webex API

Answer

Use Server-Sent Events (SSE) from the Webex API

Answer

Poll the messages endpoint every second

Question 14

In a Docker Compose file, you want to ensure that the 'web' service starts only after the 'db' service is healthy. Which key should you use under the 'web' service?

Accepted Answer

depends_on. In Docker Compose, the `depends_on` key with the `condition: service_healthy` option ensures that the `web` service starts only after the `db` service has passed its health check. This is defined in the `db` service using a `healthcheck` directive, and Compose waits for the healthy state before starting dependent services.

Answer

networks

Answer

links

Question 15

Which TWO of the following are valid branching strategies in Git? (Choose two.)

Accepted Answer

GitFlow. GitFlow is a valid branching strategy that defines a strict model for managing releases, hotfixes, and feature development using dedicated branches like 'develop', 'release/*', and 'hotfix/*'. It is widely used in enterprise environments to maintain a clean history and support parallel development.

Answer

Linear branching

Answer

Monolithic branching

Answer

Copy-on-write branching