200-901 Practice Exam 55 — 20 Questions

Question 1

Which Python list comprehension correctly creates a list of squares for even numbers from 0 to 10?

Accepted Answer

[x**2 for x in range(11) if x % 2 == 0]. It uses list comprehension syntax with `x**2` to square each number, iterates over `range(11)` to include numbers 0 through 10, and applies the condition `if x % 2 == 0` to filter only even numbers. This produces the list `[0, 4, 16, 36, 64, 100]` as required.

Answer

[x*2 for x in range(11) if x % 2 == 0]

Answer

[x**2 for x in range(10) if x % 2]

Answer

[x**2 for x in range(10) if x % 2 == 0]

Question 2

A developer is building a REST API for a Cisco DNA Center application. The API must allow external partners to retrieve network device inventory. Which security mechanism should be implemented to ensure that only authorized partners can access the API while maintaining the ability to revoke access for a specific partner without affecting others?

Accepted Answer

Use unique API keys per partner. Unique API keys per partner provide a simple, scalable mechanism to authenticate and authorize individual partners. Each key can be independently revoked without affecting other partners' access, directly meeting the requirement for granular access control. API keys are a common choice for server-to-server integrations where a lightweight, token-based authentication is sufficient.

Answer

Whitelist partner IP addresses in the API gateway firewall

Answer

Require HTTP basic authentication with a shared username and password

Answer

Implement OAuth 2.0 with client credentials grant

Question 3

An automation engineer is writing a Python script to interact with a REST API that requires authentication. The API returns a 403 Forbidden status. Which scenario best explains this response?

Accepted Answer

The authentication token is invalid, and the request is not allowed.. A 403 Forbidden status code indicates that the server understood the request but refuses to authorize it. In the context of a REST API that requires authentication, a 403 is typically returned when the client is authenticated but lacks sufficient permissions to access the resource. It can also be returned for invalid or expired tokens when the server can identify the user and explicitly denies access without offering a challenge (unlike 401, which includes a WWW-Authenticate header to prompt for credentials). A missing token, however, results in a 401 Unauthorized, as the client has not provided any authentication.

Answer

The request was malformed and the server cannot process it.

Answer

The requested resource does not exist on the server.

Answer

The server is temporarily unavailable due to maintenance.

Question 4

Which TWO statements about REST API design best practices are correct?

Accepted Answer

Resources should be represented using nouns in the URI. REST API best practices dictate that URIs should represent resources (nouns), not actions. For example, '/users' or '/orders' clearly identifies the resource being manipulated, while verbs like '/getUsers' or '/createOrder' are discouraged as they conflate the resource with the operation.

Answer

API versioning should be implemented using query parameters only

Answer

HTTP PUT method should be used for partial updates to a resource

Answer

Responses should return only HTTP status codes without a body

Question 5

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 6

Which two of the following are valid ways to authenticate to the Cisco DNA Center API?

Accepted Answer

Provide API token in HTTP header. The Cisco DNA Center API uses token-based authentication. After obtaining a token via a POST request to the /dna/system/api/v1/auth/token endpoint with valid credentials, the token must be included in the HTTP header as 'X-Auth-Token: <token>' for all subsequent API requests. This is the standard method for authenticating REST API calls to Cisco DNA Center.

Answer

Use SNMP v3

Answer

Use SAML assertion

Answer

Use SSH key

Question 7

A developer has a Docker container running a database. They need to inspect the database logs to debug a connection issue. Which command will show the logs in real-time?

Accepted Answer

docker logs -f my-db. The `docker logs -f` command attaches to the container's stdout/stderr streams and follows new output in real-time, which is exactly what is needed to debug a live connection issue. The `-f` flag (short for `--follow`) continuously prints log lines as they are written, allowing the developer to observe database connection attempts and errors as they occur.

Answer

docker exec my-db tail -f /var/log/mysql

Answer

docker logs --tail 100 my-db

Answer

docker logs my-db

Question 8

In a Kubernetes cluster, a developer needs to ensure that a set of pods can be accessed by other pods using a stable IP address and DNS name, even if pods are recreated. Which resource should be created?

Accepted Answer

Service. A Service in Kubernetes provides a stable virtual IP (ClusterIP) and a DNS name (via CoreDNS) that persists across pod restarts and rescheduling. This allows other pods to reliably discover and communicate with the set of pods behind the Service, regardless of individual pod IP changes.

Answer

ConfigMap

Answer

Namespace

Answer

Deployment

Question 9

A developer is creating a REST API client that needs to authenticate using credentials passed in the HTTP header. Which header should be used?

Accepted Answer

Authorization. The Authorization header is the standard HTTP header used to transmit credentials (such as Basic, Bearer, or Digest tokens) to authenticate a REST API client. RFC 7235 defines this header as the mechanism for carrying authentication information from the client to the server, making it the correct choice for passing credentials in the HTTP header.

Answer

Host

Answer

Content-Type

Answer

Cookie

Question 10

Which Python data type is mutable and unordered?

Accepted Answer

Dictionary. Options C (Dictionary) and D (Set) are both correct because dictionaries and sets are mutable and unordered. Dictionaries store key-value pairs and sets store unique elements, both allowing addition/removal without guaranteed order (prior to Python 3.7 for dicts, and always for sets). Lists (A) are mutable but ordered, and tuples (B) are immutable and ordered, making them incorrect.

Answer

List

Answer

Tuple

Question 11

Refer to the exhibit. An Ansible playbook is intended to set the description on GigabitEthernet0/1. However, the playbook fails because the device does not have that interface. What is the most likely reason?

Accepted Answer

The specified interface does not exist on the device. The playbook explicitly targets GigabitEthernet0/1 using the `interface` attribute under `lines`, and the error indicates the device does not have that interface. Ansible's ios_config module will fail if the specified interface does not exist on the device, as it cannot apply configuration to a non-existent logical or physical interface.

Answer

The module requires gather_facts to be yes

Answer

The hosts group is incorrect

Answer

The lines attribute is misconfigured

Question 12

Which TWO conditions are valid triggers for a webhook notification in Cisco Meraki?

Accepted Answer

Client data usage exceeds configured threshold. (Client data usage exceeds configured threshold) is a valid trigger because Meraki can send webhook notifications when data usage thresholds are exceeded. Option B (A client joins a wireless network) is also a valid trigger, corresponding to the 'Client join' event. Option C (Firmware upgrade completes) is not a standard webhook trigger. Option D (Network administrator logs in) is not a standard trigger. Option E (A new SSID is added) is not a standard trigger.

Answer

Firmware upgrade completes

Answer

Network administrator logs in

Answer

A new SSID is added

Question 13

A Cisco SD-WAN vManage API call to retrieve device inventory returns a 401 error. Which step is most likely missing?

Accepted Answer

The authentication token is expired or invalid. A 401 Unauthorized error in Cisco SD-WAN vManage API indicates that the request lacks valid authentication credentials. The vManage API uses token-based authentication (typically a JSON Web Token, JWT) obtained via a POST to /j_security_check or /authenticate. If the token is expired, malformed, or not included in the Authorization header, the API returns 401. This is the most likely cause because the other options would produce different HTTP status codes (e.g., 400 for missing fields, 502 for unreachable device, 404 for incorrect endpoint).

Answer

The request body is missing required fields

Answer

The device is unreachable

Answer

The API endpoint is incorrect

Question 14

In the MVC (Model-View-Controller) pattern, which component is responsible for handling user input and updating the model?

Accepted Answer

Controller. In the MVC pattern, the Controller is the component that receives user input (e.g., HTTP requests, button clicks) and translates it into commands that update the Model. It acts as the intermediary between the View and the Model, ensuring that user actions trigger appropriate changes in the application's data layer.

Answer

Model

Answer

Router

Answer

View

Question 15

Which three capabilities are offered by the Cisco DNA Center REST API?

Accepted Answer

Intent-based API for business intent deployment. Cisco DNA Center's REST API offers an intent-based API that allows you to express business intent (e.g., 'deploy QoS for voice traffic') rather than configuring individual device commands. This abstraction layer translates high-level policies into device-specific configurations, enabling network automation and assurance. It is a core capability of the Cisco Platform Abstraction Layer (PAL).

Answer

Real-time packet capture

Answer

Direct command-line execution on managed devices

Question 16

A Kubernetes Deployment is configured with rolling update strategy. A new version of the image is pushed, and the deployment is updated. During the rollout, the new pods are failing health checks. Which command can be used to pause the rollout and prevent further updates?

Accepted Answer

kubectl rollout pause deployment/myapp. kubectl rollout pause suspends the rollout. kubectl rollout undo rolls back to previous revision. kubectl rollout status shows status, and kubectl delete does not pause rollout.

Answer

kubectl rollout undo deployment/myapp

Answer

kubectl delete deployment/myapp

Answer

kubectl rollout status deployment/myapp

Question 17

Which three statements are true about the Cisco Catalyst Center (formerly DNA Center) intent API? (Choose three.)

Accepted Answer

The base URL for the API includes the Catalyst Center hostname and port.. The Cisco Catalyst Center intent API uses a base URL that includes the Catalyst Center hostname (or IP address) and port (typically 443 for HTTPS). For example, the base URL is formatted as `https://<catalyst-center-hostname>:443/dna/intent/api/v1/`. This is required to direct API calls to the specific Catalyst Center instance.

Answer

The API uses only GET and POST methods.

Answer

It requires an API key passed in the X-Cisco-Meraki-API-Key header.

Question 18

A developer is deploying a containerized application to a Kubernetes cluster. To ensure that the application can securely access a third-party API, what is the best practice for storing the API key?

Accepted Answer

Store it as a Kubernetes Secret and mount it as an environment variable.. Kubernetes Secrets are designed for sensitive data and can be mounted as environment variables. Option B is insecure because hardcoding keys in images exposes them. Option C is incorrect because service account tokens are for cluster authentication, not external APIs. Option D is incorrect because ConfigMaps are for non-sensitive configuration data.

Answer

Hardcode the API key in the Docker image.

Answer

Use a service account token.

Answer

Store it in a ConfigMap and reference it from the pod.

Question 19

A developer needs to read a JSON configuration file and parse it into a Python dictionary. The file contains nested objects. Which code snippet correctly accomplishes this?

Accepted Answer

with open('config.json', 'r') as f: data = json.load(f). The correct approach is to open the file with a context manager and use json.load() with the file object to parse the JSON directly into a Python dictionary. json.loads() is for parsing a JSON string, not a file object.

Answer

with open('config.json', 'r') as f: data = json.loads(f)

Answer

data = json.loads(open('config.json', 'r').read())

Answer

with open('config.json', 'r') as f: data = json.dumps(f.read())

Question 20

Which two HTTP methods are considered idempotent? (Choose two.)

Accepted Answer

PUT. GET and PUT are both idempotent. Idempotent methods produce the same result when called multiple times. GET is idempotent because it retrieves a resource without side effects. PUT is idempotent because multiple identical PUT requests result in the same resource state. POST is not idempotent because it creates new resources. PATCH is not idempotent because the same patch may have different effects on different resource states. DELETE is also idempotent, but the question specifically asks for two methods, and GET and PUT are universally recognized as idempotent.

Answer

POST

Answer

PATCH

Answer

DELETE