200-901 Practice Test 43 — 15 Questions

Question 1

In Docker, which command is used to build an image from a Dockerfile and tag it as 'myapp:v1'?

Accepted Answer

docker build -t myapp:v1 .. The `docker build -t myapp:v1 .` command builds a Docker image from the Dockerfile in the current directory and tags it with the name `myapp` and version tag `v1`. The `-t` flag assigns the tag, and the dot (`.`) specifies the build context (the current directory). This is the standard Docker command for building and tagging images.

Answer

docker run -t myapp:v1 .

Answer

docker create myapp:v1 .

Answer

docker commit myapp:v1 .

Question 2

Which HTTP status code indicates that a POST request successfully created a new resource?

Accepted Answer

201 Created. HTTP 201 Created is the standard response indicating that a request (typically POST) has succeeded and resulted in the creation of a new resource. The response often includes a Location header pointing to the URI of the newly created resource, per RFC 7231.

Answer

204 No Content

Answer

301 Moved Permanently

Answer

200 OK

Question 3

When using RESTCONF to configure a network device, what Content-Type header should be set in the HTTP request to indicate YANG data in JSON format?

Accepted Answer

application/yang-data+json. RFC 8040 defines the media type for YANG-modeled data encoded in JSON as 'application/yang-data+json'. When sending a RESTCONF request with a JSON body, the Content-Type header must be set to this value so the device knows to parse the payload against the YANG model using the JSON encoding rules.

Answer

application/yang

Answer

application/xml

Answer

application/json

Question 4

Which DNS record type is used to verify domain ownership for email security protocols like SPF and DKIM?

Accepted Answer

TXT. SPF and DKIM records are stored as TXT records in DNS. SPF records specify which mail servers are authorized to send email for a domain, while DKIM records contain a public key used to verify email signatures. Both are implemented via TXT records, not other record types.

Answer

CNAME

Answer

MX

Answer

NS

Question 5

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 6

A developer wants to create a Docker image that runs a Python application. Which instruction should be placed at the end of the Dockerfile to specify the command that runs when the container starts?

Accepted Answer

CMD. CMD specifies the default command to run when the container starts, and it can be overridden by providing a command at runtime. ENTRYPOINT is similar but not easily overridden. RUN executes during build. COPY copies files during build.

Answer

RUN

Answer

ENTRYPOINT

Answer

COPY

Question 7

When designing a REST API for managing network devices, which two principles should be followed to ensure statelessness?

Accepted Answer

All state information is stored on the client.. Statelessness in REST means the server does not retain any client context between requests, so option A is correct: all state information is stored on the client, which sends whatever context is needed with each call. Option D is also correct because each request from client to server must contain all information needed to understand and complete the request, allowing any server instance to handle it independently. Option B is wrong because maintaining session data and identifying clients via cookies is the opposite of statelessness, creating server-side session state. Option C is unrelated to statelessness; version numbers in endpoints address backward compatibility, not state management. Option E is incorrect because POST is generally non-idempotent, and idempotency of responses is not a statelessness principle.

Answer

The server maintains session data and identifies clients via cookies.

Answer

API endpoints include version numbers to support backward compatibility.

Answer

Responses are idempotent for all POST requests.

Question 8

A developer needs to create a Python script that makes a GET request to a REST API to retrieve a list of network devices. The API uses query parameters to filter by device type and status. Which TWO code snippets correctly include query parameters using the requests library? (Choose two.)

Accepted Answer

requests.get('https://api.example.com/devices', params={'type': 'router', 'status': 'active'}). Option A is correct because requests.get() accepts a params dictionary, which the requests library automatically URL-encodes and appends to the URL as query parameters (e.g., ?type=router&status=active). Option C is correct because the query parameters are already embedded directly in the URL string after the ? character, separated by &, which is the standard HTTP way to pass query parameters on a GET request. Option B is incorrect because the data parameter sends a form-encoded body, which is not used for GET query parameters and would not appear in the URL. Option D is incorrect because the json parameter serializes the dictionary into a JSON request body, not query parameters. Option E is incorrect because the headers parameter sets HTTP request headers, not URL query parameters.

Answer

requests.get('https://api.example.com/devices', data={'type': 'router', 'status': 'active'})

Answer

requests.get('https://api.example.com/devices', json={'type': 'router', 'status': 'active'})

Answer

requests.get('https://api.example.com/devices', headers={'type': 'router', 'status': 'active'})

Question 9

Which TWO of the following are true about NETCONF capabilities as defined in RFC 6241?

Accepted Answer

The operation supports 'merge', 'replace', 'create', 'delete', and 'remove' operations.. RFC 6241 defines the operation with the 'merge', 'replace', 'create', 'delete', and 'remove' operations. These allow granular modification of configuration data, with 'merge' being the default behavior if no operation attribute is specified.

Answer

The <edit-config> operation replaces the entire configuration by default.

Answer

The :rollback-on-error capability is mandatory.

Answer

The <running> configuration datastore is optional.

Question 10

A developer wants to run a Docker container in detached mode, mapping host port 8080 to container port 80, and mounting a host directory for persistent data. Which command accomplishes this?

Accepted Answer

docker run -d -p 8080:80 -v /host/data:/container/data myapp. The correct command is `docker run -d -p 8080:80 -v /host/data:/container/data myapp`. The `-d` flag runs the container in detached mode (in the background), `-p 8080:80` maps host port 8080 to container port 80, and `-v /host/data:/container/data` mounts the host directory `/host/data` to the container directory `/container/data`. This combination directly satisfies all requirements: detached mode, port mapping, and persistent volume mount.

Answer

docker run -it -p 8080:80 -v /host/data:/container/data myapp

Answer

docker start -d -p 8080:80 -v /host/data:/container/data myapp

Answer

docker compose up -d -p 8080:80 -v /host/data:/container/data myapp

Question 11

An application developer is using a protocol that does not require a connection setup and has minimal header overhead. Which transport protocol is being used?

Accepted Answer

UDP. UDP (User Datagram Protocol) is a connectionless transport-layer protocol that does not require a handshake (no SYN/SYN-ACK/ACK) and has minimal header overhead (only 8 bytes, compared to TCP's 20 bytes). This makes it ideal for applications like DNS queries, streaming media, or real-time communications where low latency is more critical than guaranteed delivery.

Answer

TCP

Answer

HTTP

Answer

ICMP

Question 12

Which TWO commands are used to view information about Docker containers? (Select two.)

Accepted Answer

docker logs -f. Option B, `docker logs -f`, is correct because it retrieves and follows the stdout/stderr log output of a running (or stopped) container, which is information about that container's runtime behavior. Option E, `docker ps -a`, is correct because it lists all containers, including stopped ones, showing container IDs, images, status, ports, and names. Option A, `docker build`, is wrong because it builds a new image from a Dockerfile rather than viewing container information. Option C, `docker images`, is wrong because it lists locally stored images, not containers. Option D, `docker volume ls`, is wrong because it lists Docker volumes, which are separate storage resources, not containers.

Answer

docker build

Answer

docker images

Answer

docker volume ls

Question 13

A developer needs to send a message to a Webex room using the API. Which HTTP method and endpoint should they use?

Accepted Answer

POST /v1/messages. To send a message, use POST to /v1/messages with the room ID and message body.

Answer

GET /v1/messages

Answer

PUT /v1/messages

Answer

DELETE /v1/messages

Question 14

An engineer is troubleshooting a VoIP call quality issue. The call uses UDP and experiences packet loss. Which characteristic of UDP most likely contributes to the problem?

Accepted Answer

No retransmission of lost packets. UDP is a connectionless transport protocol that does not provide retransmission of lost packets. In VoIP, packet loss directly degrades call quality because lost audio data is never resent, leading to gaps or distortion in the conversation.

Answer

Ordered delivery guarantee

Answer

Connection-oriented setup

Answer

Flow control mechanism

Question 15

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'