200-901 Practice Test 3 — 30 Questions

Question 1

A developer runs 'docker run -d -p 8080:80 --name web nginx:alpine'. The container fails to start. Which command is the most appropriate to investigate the issue?

Accepted Answer

docker logs -f web. `docker logs -f web` streams the container's stdout and stderr output, which typically contains the error message explaining why the container failed to start (e.g., port conflict, missing configuration, or process crash). Since the container is not running, `docker logs` is the primary diagnostic tool to retrieve its exit logs without requiring the container to be active.

Answer

docker inspect web

Answer

docker exec -it web bash

Question 2

Refer to the exhibit. A developer sends a PUT request to the RESTCONF endpoint with the above JSON payload. The device already has interface GigabitEthernet1/0/1 configured with IP address 10.10.10.1/24. What is the expected outcome?

Accepted Answer

The request succeeds and the interface configuration remains unchanged.. D is correct because the PUT request to the RESTCONF endpoint with the provided JSON payload is an idempotent operation. Since the interface GigabitEthernet1/0/1 already exists with the exact same configuration (IP address 10.10.10.1/24), the PUT request effectively replaces the resource with the same data, resulting in no change. RESTCONF uses the HTTP PUT method to create or replace a resource, and if the resource already exists and the payload matches, the operation succeeds without modification.

Answer

The request fails because the interface already exists.

Answer

The request creates a new interface with the same configuration.

Answer

The request fails because the JSON is malformed.

Question 3

A developer is using the Cisco Webex API to send a message to a specific room. They have the room ID. Which endpoint and method should they use?

Accepted Answer

POST /v1/messages with roomId in the body. To send a message to a Webex room, the correct endpoint is POST /v1/messages with roomId in the body.

Answer

PUT /v1/messages/{messageId}

Answer

POST /v1/rooms with roomId in the body

Answer

GET /v1/messages?roomId=...

Question 4

A developer is writing an application that needs to send a large amount of data reliably over a network. Which transport layer protocol should the developer use?

Accepted Answer

TCP. TCP (Transmission Control Protocol) is the correct choice because it provides reliable, connection-oriented data delivery with acknowledgments, retransmission, and sequencing. This ensures that large amounts of data are transmitted without loss or corruption, which is critical for applications requiring data integrity.

Answer

ICMP

Answer

HTTP

Answer

UDP

Question 5

Which OSI layer is responsible for routing packets across different networks?

Accepted Answer

Layer 3 (Network). The Network layer (Layer 3) is responsible for logical addressing and routing packets between different networks. Protocols like IP (IPv4/IPv6) use routing tables and algorithms (e.g., OSPF, BGP) to determine the best path for forwarding packets across multiple hops. Without Layer 3, traffic could not leave a local broadcast domain.

Answer

Layer 1 (Physical)

Answer

Layer 4 (Transport)

Answer

Layer 2 (Data Link)

Question 6

Which TCP flag is set in the second step of the three-way handshake?

Accepted Answer

SYN and ACK. The TCP three-way handshake begins with the client sending a SYN segment to initiate a connection. In the second step, the server responds with a SYN-ACK segment, which both acknowledges the client's SYN (using the ACK flag) and synchronizes its own sequence number (using the SYN flag). This combined flag is essential for establishing a reliable, bidirectional connection.

Answer

ACK

Answer

SYN

Answer

FIN

Question 7

A Kubernetes pod needs to run a database that requires persistent storage. Which volume type should be used to store data that persists beyond the pod lifecycle?

Accepted Answer

PersistentVolumeClaim. PersistentVolumeClaim requests persistent storage that survives pod restarts. emptyDir is ephemeral, hostPath ties to a node, configMap is for configuration.

Answer

emptyDir

Answer

configMap

Answer

hostPath

Question 8

A developer wants to automate the provisioning of a UCS server using Cisco Intersight. Which authentication method is recommended for programmatic access?

Accepted Answer

API Key with HMAC signing. Cisco Intersight recommends API key authentication with HMAC signing for programmatic access because it provides a secure, non-interactive method for automation scripts and tools. The API key consists of a key ID and a secret, and each request must include an HMAC signature generated from the request details, ensuring integrity and authenticity without exposing static credentials over the network.

Answer

Basic authentication with username and password

Answer

Session token from Intersight UI

Answer

OAuth2 with client credentials

Question 9

A developer needs to retrieve the current user's details from Webex API. Which endpoint should they call?

Accepted Answer

GET /v1/people/me. GET /v1/people/me returns details of the authenticated user.

Answer

GET /v1/rooms?me=true

Answer

POST /v1/people

Answer

GET /v1/people?email=current@user.com

Question 10

Which wireless security standard provides the strongest encryption and is recommended for enterprise networks as of 2023?

Accepted Answer

WPA3. WPA3 is the latest standard with stronger encryption (SAE) and is recommended for modern networks.

Answer

WEP

Answer

TKIP

Answer

WPA2

Question 11

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 12

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 13

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 14

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 15

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 16

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 17

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 18

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 19

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 20

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