200-901 Practice Test 15 — 15 Questions

Question 1

A DevOps team is deploying a microservices application that requires both reliable data transfer and low-latency real-time communication. Which two protocols should be used for these respective requirements? (Choose two.)

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

TCP. TCP (Transmission Control Protocol) is correct for reliable data transfer because it provides connection-oriented communication with sequencing, acknowledgments, and retransmission of lost packets, ensuring data arrives intact and in order. This makes it ideal for microservices that need guaranteed delivery, such as database transactions or order processing.

Answer

ARP

Answer

ICMP

Answer

HTTP

Question 2

In a CI/CD pipeline using Jenkins, which stage is typically executed immediately after the build stage to ensure code quality before deployment?

Accepted Answer

Unit test. In a Jenkins CI/CD pipeline, the build stage compiles the code and produces artifacts. Immediately after the build, unit tests are executed to validate individual components in isolation, catching defects early before proceeding to integration or deployment stages. This aligns with the principle of 'shift-left' testing, where quality gates are applied as early as possible.

Answer

Deploy to production

Answer

Integration test

Answer

Artifact publication

Question 3

Refer to the exhibit. This JSON response was received from the Cisco DNA Center API. A developer wants to extract the software version of the first device. Which Python expression correctly retrieves '16.12.5' from the variable `data`?

Accepted Answer

data['response'][0]['softwareVersion']. The JSON response from Cisco DNA Center's API is structured with a 'response' key containing an array of device objects. To access the software version of the first device, you must first index into the array with [0] to get the first device object, then use the key 'softwareVersion' to retrieve the value '16.12.5'. The variable `data` holds the entire JSON object, so `data['response'][0]['softwareVersion']` correctly navigates this nested structure.

Answer

data[0]['softwareVersion']

Answer

data['response'][0]['version']

Answer

data['response']['softwareVersion']

Question 4

A security team is developing an application that collects network alerts from Cisco Firepower Management Center (FMC) API. The API requires OAuth2 authorization code grant flow. After obtaining an authorization code, what must the application do to get an access token?

Accepted Answer

Exchange the authorization code for an access token by calling the token endpoint with the code and client credentials.. In the OAuth2 authorization code grant flow, the authorization code is an intermediate credential that must be exchanged for an access token. The application must call the token endpoint, presenting the authorization code along with its client credentials (client ID and client secret) to receive the access token. This exchange is required by RFC 6749 and is a fundamental security measure to ensure the client is authorized to obtain the token.

Answer

Resend the authorization request with the code included in the redirect URI.

Answer

Decode the authorization code using base64 to extract the access token.

Answer

Use the authorization code directly in subsequent API requests as a bearer token.

Question 5

Which of the following is a non-overlapping channel in the 2.4 GHz Wi-Fi band?

Accepted Answer

Channel 6. In the 2.4 GHz Wi-Fi band, channels are spaced 5 MHz apart, but each channel is 22 MHz wide. To avoid overlap, channels must be separated by at least 5 channels (25 MHz). The only non-overlapping channels in North America are 1, 6, and 11. Channel 6 is one of these, making it the correct answer.

Answer

Channel 3

Answer

Channel 12

Answer

Channel 9

Question 6

An engineer needs to transfer a router configuration file to a server in the same network using a simple protocol that does not require authentication. Which protocol is best?

Accepted Answer

TFTP. TFTP (Trivial File Transfer Protocol) is the best choice because it is a lightweight, connectionless protocol that operates over UDP (port 69) and does not require any authentication or user credentials. It is commonly used for transferring router configuration files and IOS images in local network environments where simplicity and speed are prioritized over security.

Answer

SCP

Answer

FTP

Answer

HTTP

Question 7

Which HTTP method is used to partially update a resource in a RESTful API?

Accepted Answer

PATCH. The HTTP PATCH method is used to apply partial modifications to a resource. Unlike PUT, which replaces the entire resource, PATCH only updates the specified fields, making it ideal for partial updates.

Answer

POST

Answer

PUT

Answer

UPDATE

Question 8

Refer to the exhibit. A developer receives this response when making a POST request to the Cisco DNA Center API to create a new device. What is the most likely issue?

Accepted Answer

The request body is missing the required field 'ipAddress'.. The error response includes a field 'missingParameters' with the value 'ipAddress', which explicitly indicates that the request body did not include the required 'ipAddress' field. Cisco DNA Center's API for device creation requires this field to identify the device on the network. Without it, the API cannot proceed with adding the device, resulting in a 400 Bad Request.

Answer

The API endpoint is incorrect.

Answer

The device IP address is already in use.

Answer

The API token has expired.

Question 9

In a CI/CD pipeline for network changes, which practice best ensures that a configuration push does not disrupt production traffic?

Accepted Answer

Canary deployment. Canary deployment is the correct practice because it gradually introduces the configuration change to a small subset of devices or traffic before full rollout. This allows monitoring for adverse effects and automatic rollback if issues arise, minimizing the risk of production disruption. In a CI/CD pipeline for network changes, this approach aligns with incremental validation and risk mitigation.

Answer

Disable rollback

Answer

Push all changes at once

Answer

Skip validation

Question 10

A developer runs 'docker-compose up -d' for a multi-service application. What does the '-d' flag do?

Accepted Answer

It runs containers in detached mode (background). The `-d` flag in `docker-compose up -d` stands for 'detached mode', which instructs Docker Compose to run the containers in the background, freeing the terminal for other commands. This is analogous to the `-d` flag in `docker run -d` and is essential for long-running services that should not block the command-line session.

Answer

It enables debugging output

Answer

It pulls the latest images before starting

Answer

It deletes the containers after they stop

Question 11

In a docker-compose.yaml file, which key is used to define the container image to be built from a Dockerfile in the current directory?

Accepted Answer

build. The `build` key in a docker-compose.yaml file specifies the build context and optionally the Dockerfile location, instructing Docker Compose to build an image from a Dockerfile in the current directory. This is the correct key for building an image rather than using a pre-built one.

Answer

dockerfile

Answer

image

Answer

context

Question 12

Refer to the exhibit. A network engineer runs a script that queries the Cisco DNA Center site health API. The response shows Branch1 with a healthScore of 10. What is the most likely action to improve Branch1's health?

Accepted Answer

Investigate the network devices and connectivity at Branch1.. A healthScore of 10 on a scale of 0–100 indicates severe degradation, typically caused by network device failures, link flaps, or connectivity loss. Investigating the network devices and connectivity at Branch1 is the correct first step to identify and resolve the root cause, such as a down switch or a routing issue.

Answer

Increase the number of clients at Branch1.

Answer

Check the API authentication token.

Answer

Use a different API version.

Question 13

In HTTP/2, which feature allows multiple concurrent requests and responses to be interleaved on a single connection, improving performance?

Accepted Answer

Multiplexing. HTTP/2 multiplexing allows multiple streams to be sent concurrently over a single TCP connection, reducing head-of-line blocking.

Answer

Header compression (HPACK)

Answer

Server push

Answer

Binary framing

Question 14

In Software-Defined Networking (SDN), the control plane is separated from the data plane. Which of the following best describes the function of the southbound API?

Accepted Answer

Interface between the controller and network devices. Southbound API is used by the SDN controller to communicate with network devices (e.g., switches, routers) to enforce forwarding rules.

Answer

Interface between applications and the controller

Answer

Communication between two controllers

Answer

Interface between the control plane and management plane

Question 15

A developer needs to partially update a Meraki network's configuration, changing only the time zone. Which HTTP method should be used on the network resource?

Accepted Answer

PATCH. PATCH is used for partial updates in REST APIs.

Answer

PUT

Answer

DELETE

Answer

POST