DevNet Associate (Version 1.0) – Module 4 Exam Answers

Refer to the exhibit. A network administrator is using a Python script to test a REST API request. The traceback message indicates that there is an error in the URI. What is a possible issue?

• The protocol is wrong.

• The query component is missing.

• The destination host address is wrong.

• The SSL certificate is invalid.

Answer explanation

Explanation: The error message indicates “ConnectionError”. The destination host address is probably wrong because it cannot be reached.

Match the RESTful API method to CRUD function.

READ

• GET

• POST

• DELETE

• PUT/PATCH

Answer explanation

Match the RESTful API method to CRUD function.

CREATE

• POST

• GET

• DELETE

• PUT/PATCH

Answer explanation

Match the RESTful API method to CRUD function.

DELETE

• DELETE

• POST

• GET

• PUT/PATCH

Answer explanation

Match the RESTful API method to CRUD function.

UPDATE

• PUT/PATCH

• DELETE

• GET

• POST

Answer explanation

What is an architectural constraint to which a true RESTful API web service must adhere?

• It operates in a stateless way.

• It uses HTTPS to transport data.

• It must operate along with a DNS server.

• It operates as a cloud service.

Answer explanation

Explanation: Conforming to the constraints of the REST architecture is generally referred to as being “RESTful”. An API can be considered “RESTful” if it has the following features:
Client/server – The client handles the front end and the server handles the back end.
Stateless – No client data is stored on the server between requests. The session state is stored on the client.
Cacheable – Clients can cache responses locally to improve performance.

Refer to the exhibit. A network administrator is using a Python script to send a REST API request. What is the purpose of the line of code resp = requests.get(url, verify = False) ?

• It bypasses the certificate validation check.

• It tests the function of the Python requests library

• It omits the sending URL in the response.

• It skips the URL verification step and tests the resource path.

Answer explanation

Explanation: When the scheme of the URI is HTTPS, the connection performs an SSL handshake between the client and the server in order to authenticate each other. This handshake needs to be successful before the REST API request can be sent to the API server. In a development stage, APIs with HTTPS need testing and because a valid certificate is not yet obtained, the SSL handshake process can be turned off with the code line.

A client is sending a REST API request to a web server. The request includes the need for data compression. Which three values are acceptable for the Accept-Encoding request header? (Choose three.)

• *

• br

• gzip

• xz

• zip

Answer explanation

Explanation: A few of the acceptable values for the Accept-Encoding request header are gzip, compress, deflate, br, identity, and *.

What is the meaning of the term flow as it relates to the OAuth 2.0 authorization framework?

• It is a process for an API user to obtain an access token from the authorization server.

• It is the sequence of data exchanged between a REST API request and a response.

• It is a process for an API request to send authentication credentials to a web service.

• It is the number of requests contained in the token bucket.

Answer explanation

Explanation: Open Authorization, also known as OAuth, combines authentication with authorization. It is usually the recommended form of authentication/authorization for REST APIs. OAuth 2.0 enables preregistered applications to get authorization to perform REST API requests on behalf of a user without the user needing to share its credentials with the application itself. OAuth enables the user to provide credentials directly to the authorization server to obtain an access token that can be shared with the application. This process of obtaining the token is called a flow. The application then uses this token in the REST API as a Bearer Authentication. The web service for the REST API then checks the Authorization server to make sure the token is valid and that the requester is authorized to perform the request.

What is a characteristic of a RESTful API?

• It uses HTTP methods to gather and manipulate data.

• It is a southbound API.

• It facilitates the configuration changes from a network controller to end devices.

• It supports a secure data transmission between a remote user and an enterprise network.

Answer explanation

Explanation: RESTful APIs use HTTP methods to gather and manipulate data. They are northbound APIs. Because there is a defined structure for how HTTP works, it offers a consistent way to interact with RESTful APIs from multiple vendors.