200-901 Practice Test 8 — 10 Questions

Question 1

Which tool is specifically designed for model-driven programmability using YANG data models?

Accepted Answer

NETCONF. NETCONF is the correct answer because it is a network management protocol specifically designed to operate with YANG data models, using XML or JSON encoding to transport configuration and state data. YANG defines the structure of the data, and NETCONF provides the operations (get, edit-config, etc.) to manipulate that data in a model-driven, programmatic way. This makes NETCONF the standard tool for model-driven programmability in modern network automation.

Answer

SNMP

Answer

CLI

Answer

Ansible

Question 2

A developer creates a Dockerfile with the following content: FROM python:3.9-slim, COPY app.py /app/, RUN pip install flask, EXPOSE 5000, CMD ["python", "/app/app.py"]. When building the image with 'docker build -t myapp .', what is the purpose of the EXPOSE instruction?

Accepted Answer

It informs Docker that the container listens on port 5000, but the port must be published at runtime.. EXPOSE documents that the container listens on port 5000 at runtime. It does not publish the port; that requires -p flag when running the container.

Answer

It automatically publishes port 5000 to a random host port.

Answer

It installs the Flask framework on port 5000.

Answer

It maps host port 5000 to container port 5000.

Question 3

A developer needs to store a database password securely in a Kubernetes cluster. Which resource should be used?

Accepted Answer

Secret. Secrets are designed to store sensitive information like passwords, encoded in base64 but intended for secrets. ConfigMaps are for non-sensitive data.

Answer

PersistentVolume

Answer

ConfigMap

Answer

ServiceAccount

Question 4

At which layer of the OSI model do MAC addresses operate?

Accepted Answer

Layer 2 – Data Link. MAC addresses operate at Layer 2 (Data Link) of the OSI model because they are used for local network addressing and frame delivery between directly connected devices. The Data Link layer encapsulates packets into frames and uses MAC addresses to identify source and destination interfaces on the same network segment, as defined by IEEE 802 standards.

Answer

Layer 1 – Physical

Answer

Layer 4 – Transport

Answer

Layer 3 – Network

Question 5

A team uses GitHub Actions for CI/CD. Their workflow includes a job that builds a Docker image and pushes it to a private registry. The job needs to authenticate to the registry using secrets stored in GitHub. Which approach is most secure for passing credentials?

Accepted Answer

Use GitHub Secrets and reference them with ${{ secrets.REGISTRY_PASSWORD }}.. GitHub Secrets store encrypted values at the repository, environment, or organization level, and they are injected into the workflow at runtime as masked values referenced via the ${{ secrets.NAME }} context. They are never written to logs (GitHub automatically redacts them), are not exposed to forked PRs by default, and can be scoped to specific environments with required reviewers. This makes them the correct mechanism for passing registry credentials securely to a CI/CD job.

Answer

Embed the password directly in the workflow YAML file.

Answer

Store the password in a plain text file in the repository and read it during the build.

Answer

Use environment variables set in the runner's local .env file.

Question 6

A team uses Chef to manage network device configurations. Which component of Chef is responsible for storing configuration policy and distributing it to nodes?

Accepted Answer

Chef Server. The Chef Server is the central hub that stores configuration policies (cookbooks, roles, environments, data bags) and distributes them to nodes via a REST API. When a Chef Client runs on a node, it authenticates with the Chef Server and downloads the relevant policy to converge the node to the desired state. This makes the Chef Server the authoritative source of configuration policy in a Chef architecture.

Answer

Knife

Answer

Chef Client

Answer

Supermarket

Question 7

In a Docker Compose file, a service 'web' depends on 'db'. The 'db' service uses a volume to persist data. Which compose key ensures that the database starts before the web service?

Accepted Answer

depends_on. depends_on creates a startup order: Docker Compose starts 'db' before 'web'. It does not wait for 'db' to be ready; that requires healthchecks.

Answer

volumes

Answer

links

Answer

networks

Question 8

Which THREE options are valid methods to expose a Kubernetes service to external traffic?

Accepted Answer

NodePort. NodePort (B) is correct because it allocates a static port in the 30000-32767 range on every node's IP, allowing external clients to reach the service via :. Ingress (D) is correct because it provides HTTP/HTTPS routing from outside the cluster to internal services through an ingress controller acting as a reverse proxy. LoadBalancer (E) is correct because it provisions an external load balancer (e.g., via a cloud provider) with a public IP that forwards traffic to the service's NodePort. ExternalName (A) is not a valid exposure method for external traffic; it merely creates a CNAME DNS alias to an external hostname without proxying traffic. ClusterIP (C) is incorrect because it only exposes the service on an internal cluster IP reachable solely from within the cluster.

Answer

ExternalName

Answer

ClusterIP

Question 9

Which TWO HTTP status codes indicate client errors?

Accepted Answer

404 Not Found. Option B, 404 Not Found, is correct because it is a 4xx-class status code signaling that the client requested a resource the server cannot locate, which is by definition a client-side error. Option C, 400 Bad Request, is also correct because it is a 4xx status returned when the server cannot process the request due to malformed syntax, invalid framing, or deceptive routing sent by the client. The unmarked options do not belong: 500 Internal Server Error (A) is a 5xx server error indicating the server failed unexpectedly, while 200 OK (D) and 201 Created (E) are 2xx success codes confirming the request was received, understood, and processed (with 201 specifically indicating a new resource was created).

Answer

500 Internal Server Error

Answer

200 OK

Answer

201 Created

Question 10

A network engineer is tasked with segmenting a large broadcast domain into smaller ones using VLANs. In the OSI model, at which layer does a VLAN operate?

Accepted Answer

Layer 2 - Data Link. VLANs operate at Layer 2 (Data Link) of the OSI model because they segment broadcast domains by tagging Ethernet frames with VLAN IDs (802.1Q). This allows logical separation of networks without regard to physical location, and switches use MAC addresses to forward frames within VLANs. Layer 2 is where framing, MAC addressing, and VLAN tagging occur.

Answer

Layer 4 - Transport

Answer

Layer 1 - Physical

Answer

Layer 3 - Network