200-901 Understanding and Using APIs Practice Test 7 — 15 Questions

Question 1

In gNMI, what is the difference between dial-in and dial-out streaming?

Accepted Answer

Dial-in: client initiates subscription and receives data; dial-out: device pushes data to a configured receiver. In gNMI, dial-in streaming refers to the client initiating a subscription request to the device, which then streams telemetry data back over the same gRPC session. Dial-out streaming, on the other hand, is a server-initiated model where the device (gNMI target) pushes telemetry data to a pre-configured receiver (collector) without waiting for a client request. Option C correctly captures this distinction: dial-in has the client subscribe and receive data, while dial-out has the device push data to a configured receiver.

Answer

Dial-in is for configuration, dial-out for telemetry

Answer

Dial-in: device initiates the connection; dial-out: client initiates

Answer

Dial-in uses gRPC, dial-out uses HTTP

Question 2

Which Cisco platform provides an Intent API for network automation, including endpoints for network-device, topology, and site hierarchy?

Accepted Answer

Cisco Catalyst Center. Cisco Catalyst Center (formerly DNA Center) provides an Intent API that abstracts network intent into RESTful endpoints. This API includes specific endpoints for managing network devices, retrieving topology views, and interacting with site hierarchy, enabling declarative network automation without low-level device configuration.

Answer

Cisco Webex

Answer

Cisco IOS XE

Answer

Meraki Dashboard

Question 3

A developer needs to retrieve a list of network devices from Cisco DNA Center with pagination. Which TWO URL components are typically used for offset/limit pagination?

Accepted Answer

Query parameter 'limit'. Options C and D are correct because Cisco DNA Center's REST APIs implement offset/limit pagination through the query parameters 'limit' (the maximum number of records to return per page) and 'offset' (the number of records to skip before starting to return results), so a request such as GET /dna/intent/api/v1/network-device?offset=1&limit=10 retrieves the second page of ten devices. Option A is incorrect because the Link header is a response header used by some APIs (e.g., GitHub) to convey pagination URLs, not a URL component the developer supplies in the request. Option B is incorrect because Cisco DNA Center does not use a 'page' query parameter for offset/limit pagination. Option E is incorrect because 'page' is not a path parameter in these API endpoints; path parameters identify specific resources, not pagination windows.

Answer

Link header

Answer

Query parameter 'page'

Answer

Path parameter 'page'

Question 4

Which THREE statements about NETCONF are correct?

Accepted Answer

NETCONF uses SSH as the transport protocol.. Option B is correct because NETCONF (RFC 6241) defines SSH as its mandatory transport protocol, mapping NETCONF sessions to the SSH subsystem 'netconf' on TCP port 830. Option C is correct because the operation is the standard NETCONF RPC for loading configuration changes into a specified datastore (running, candidate, or startup), supporting merge, replace, create, and delete operations. Option E is correct because all NETCONF protocol operations are encoded as XML-based RPCs within and elements, using the NETCONF base namespace. Option A is incorrect because HTTP is not the NETCONF transport; NETCONF over HTTP is not defined in the base specification (RESTCONF is the HTTP-based alternative). Option D is incorrect because retrieves only configuration data from a datastore; state data is retrieved with the separate operation.

Answer

NETCONF uses HTTP as the transport protocol.

Answer

The <get-config> operation retrieves both configuration and state data.

Question 5

Which HTTP method should be used to replace an entire existing resource in a RESTful API?

Accepted Answer

PUT. PUT is the correct HTTP method for replacing an entire existing resource in a RESTful API because it is defined as idempotent in RFC 7231, meaning the client sends a full representation of the resource to replace the current state at the target URI. Unlike POST, PUT is intended for full updates where the client specifies the URI and the server replaces the resource entirely with the provided payload.

Answer

POST

Answer

PATCH

Answer

DELETE

Question 6

A developer is making a GET request to a REST API and needs to specify that the response should be in JSON format. Which HTTP header should be set?

Accepted Answer

Accept. The Accept header is used by the client to tell the server which media types (e.g., application/json) it can understand and prefers for the response. In a GET request, the client does not send a body, so Content-Type is irrelevant for specifying the response format. Setting Accept: application/json ensures the server returns JSON if it supports that format.

Answer

Content-Type

Answer

User-Agent

Answer

Authorization

Question 7

A network automation engineer is using the Cisco DNA Center intent API to retrieve a list of network devices. Which API endpoint should be used?

Accepted Answer

GET /dna/intent/api/v1/network-device. The correct endpoint is GET /dna/intent/api/v1/network-device because the Cisco DNA Center intent API uses this path to retrieve a list of all network devices managed by the controller. The 'network-device' resource is specifically designed for device inventory operations, returning details such as hostname, IP address, platform ID, and software version. This aligns with the intent API's purpose of abstracting underlying complexities into business-relevant resources.

Answer

GET /dna/intent/api/v1/site

Answer

GET /dna/intent/api/v1/topology

Answer

GET /dna/intent/api/v1/issue

Question 8

When using the Meraki Dashboard API, what is the correct method to authenticate requests?

Accepted Answer

Include an API key in the X-Cisco-Meraki-API-Key header. The Meraki Dashboard API uses a unique API key for authentication, which must be included in the `X-Cisco-Meraki-API-Key` header. This key is generated per user in the Meraki Dashboard and identifies the request without requiring a session or password. Option D correctly specifies this custom header, which is the only supported method for authenticating requests to the Meraki API.

Answer

Include an API key in the Authorization header as a Bearer token

Answer

Use a session token obtained from a login endpoint

Answer

Use Basic authentication with username and password

Question 9

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 10

A developer is using the ncclient library in Python to connect to a network device via NETCONF. Which operation should be used to modify the running configuration and commit the changes?

Accepted Answer

edit_config() followed by commit(). In NETCONF, the `edit-config()` operation is used to modify the running configuration, and the `commit()` operation is required to make those changes permanent when the device operates in candidate configuration mode. The ncclient library provides these methods to align with the NETCONF protocol's standard operations.

Answer

validate() followed by get_config()

Answer

get_config() followed by copy_config()

Answer

discard_changes() followed by edit_config()

Question 11

A REST API uses offset and limit parameters for pagination. If the first request returns items 0-49 with limit=50 and offset=0, how should the next request be constructed to get the next page?

Accepted Answer

offset=50, limit=50. Pagination with offset and limit works by advancing the offset by the limit value to fetch the next set of items. The first request returned items 0-49 (offset=0, limit=50), so the next request should start at offset=50 with the same limit=50 to retrieve items 50-99. This ensures no overlap and no gaps in the data.

Answer

offset=1, limit=50

Answer

offset=50, limit=100

Answer

offset=0, limit=100

Question 12

In the OAuth 2.0 authorization code flow, what does the client receive after the user grants authorization?

Accepted Answer

An authorization code. In the OAuth 2.0 authorization code flow, after the user grants authorization, the authorization server redirects the client with an authorization code in the query string. This code is a temporary credential that the client must exchange for an access token by sending it along with its client credentials to the token endpoint. The authorization code itself is not the final token; it is a one-time-use intermediary that prevents the access token from being exposed to the user agent.

Answer

A client secret

Answer

A refresh token

Answer

An access token

Question 13

Which HTTP method is idempotent and safe?

Accepted Answer

GET. GET is both idempotent and safe because it is designed to retrieve a resource without causing any side effects on the server. According to RFC 7231, a safe method does not modify the resource state, and an idempotent method guarantees that multiple identical requests produce the same result as a single request. GET satisfies both conditions, as it never alters server state and repeating the same GET request returns the same representation.

Answer

DELETE

Answer

POST

Answer

PUT

Question 14

A developer needs to create a Postman collection that uses a variable for the base URL and a token variable for authentication. The token is obtained from a login request and must be reused across requests. Where should the token variable be defined to persist across all requests in the collection?

Accepted Answer

As a collection variable. Collection variables in Postman are scoped to the entire collection, meaning they persist across all requests within that collection. By storing the token as a collection variable after the login request, it can be reused in subsequent requests without re-authentication. This is the recommended approach for sharing authentication tokens across requests in a Postman collection.

Answer

As a data variable from a CSV file

Answer

As a global variable

Answer

As a local variable in the login request

Question 15

When using gRPC/gNMI for model-driven telemetry, which mode allows the network device to push telemetry data to a collector without the collector initiating the connection?

Accepted Answer

Dial-out. In gRPC/gNMI-based model-driven telemetry, dial-out mode enables the network device (server) to initiate a connection to the collector (client) and push telemetry data without any prior request from the collector. This is the correct mode for unsolicited streaming telemetry, as defined in the gNMI specification (gRPC Network Management Interface).

Answer

gRPC streaming

Answer

Streaming pull

Answer

Dial-in