200-901 Practice Test 42 — 15 Questions

Question 1

A Python function needs to accept a variable number of keyword arguments. Which parameter syntax should be used?

Accepted Answer

**kwargs. In Python, the **kwargs syntax allows a function to accept a variable number of keyword arguments by collecting them into a dictionary. This is the correct parameter syntax for handling arbitrary keyword arguments, as specified in Python's function definition rules.

Answer

*kwargs

Answer

*args

Answer

&kwargs

Question 2

Refer to the exhibit. A switch is configured with the shown trunk port. After connecting the uplink, the switch logs show repeated 'errdisable' state transitions on this port. The core switch is configured with the same allowed VLAN list. Which configuration change is most likely to resolve the issue?

Accepted Answer

Remove the spanning-tree portfast trunk command from the interface.. The 'errdisable' state transitions on a trunk port are typically caused by a spanning-tree BPDU guard violation when PortFast is enabled. The 'spanning-tree portfast trunk' command enables PortFast on the trunk, which bypasses the normal listening/learning states and can cause the port to be placed into errdisable state if a BPDU is received from the core switch. Removing this command allows the trunk port to participate in standard spanning-tree convergence, preventing the repeated errdisable transitions.

Answer

Change the switchport mode to dynamic desirable.

Answer

Add VLAN 1 to the allowed VLAN list.

Answer

Add the spanning-tree bpduguard enable command to the interface.

Question 3

A developer is using the Cisco Webex API to create a room and add members. The API requires an access token with the appropriate scopes. The developer receives a 401 Unauthorized error when trying to create a room. What is the most likely cause?

Accepted Answer

The access token has expired. A 401 Unauthorized error in Cisco Webex APIs indicates an authentication failure, such as a missing or expired access token. Insufficient scopes result in a 403 Forbidden error, not a 401. Since the developer is using an access token, the most likely cause is that the token has expired. A missing token would also cause a 401, but an expired token is a common and plausible scenario given the developer is actively using the API.

Answer

The access token only has the 'spark:rooms_read' scope

Answer

The access token has the 'spark:memberships_write' scope but not 'spark:rooms_write'

Answer

The access token is not being sent in the Authorization header

Question 4

A technician needs to verify the IP address of a remote server using DNS. Which command should be used on a Cisco IOS device?

Accepted Answer

nslookup server.example.com. The `nslookup` command is used to query DNS servers to resolve a hostname to an IP address. On a Cisco IOS device, `nslookup` sends a DNS query for the specified hostname and returns the corresponding IP address, making it the correct tool for verifying a remote server's IP via DNS.

Answer

traceroute server.example.com

Answer

show hosts server.example.com

Answer

ping server.example.com

Question 5

A Python function needs to handle both expected and unexpected errors during file I/O. Which THREE constructs are essential for robust exception handling? (Choose three.)

Accepted Answer

except. (except) is correct because it is the block that catches exceptions raised during execution of the try block. Without an except clause, any error would propagate unhandled and crash the program. In file I/O, this is essential to catch specific exceptions like FileNotFoundError or PermissionError and respond appropriately.

Answer

else

Answer

raise

Question 6

A network automation script uses RESTCONF to configure a router. The script receives an HTTP 409 Conflict response. What is the most likely cause?

Accepted Answer

The resource already exists. RESTCONF uses HTTP status codes to indicate the result of an operation. An HTTP 409 Conflict specifically means the request could not be completed due to a conflict with the current state of the resource. In the context of a network automation script using RESTCONF to configure a router, this most commonly occurs when the script attempts to create a resource (e.g., an interface or VLAN) that already exists, violating the resource's uniqueness constraint.

Answer

The router is unreachable

Answer

The request body is malformed

Answer

Incorrect authentication

Question 7

What does the Git command 'git log --oneline' display?

Accepted Answer

A summary of each commit on one line. The --oneline flag condenses each commit to a single line showing the commit hash and message.

Answer

A list of files changed in the last commit

Answer

The branches and their latest commits

Answer

The differences between the working directory and the last commit

Question 8

Which Docker network driver allows a container to share the host's network stack, giving it direct access to host interfaces?

Accepted Answer

host. The 'host' network driver in Docker removes network isolation between the container and the host, allowing the container to use the host's network stack directly. This means the container binds to host interfaces and ports without NAT or port mapping, giving it direct access to the host's IP address and network configuration.

Answer

none

Answer

overlay

Answer

bridge

Question 9

Which Docker command is used to build an image from a Dockerfile?

Accepted Answer

docker build. The `docker build` command reads the instructions in a Dockerfile and assembles a Docker image layer by layer. Each instruction in the Dockerfile (e.g., FROM, RUN, COPY) creates a new layer that is cached and reused, making subsequent builds faster. This is the standard and only command designed specifically for building images from a Dockerfile.

Answer

docker run

Answer

docker commit

Answer

docker create

Question 10

A Kubernetes cluster has a deployment named 'frontend' that needs to be updated to a new image version. The update should be performed with zero downtime. Which three kubectl commands or approaches can achieve this? (Choose three.)

Accepted Answer

kubectl set image deployment/frontend frontend=myimage:v2. Rolling updates can be done by editing the deployment, applying a new YAML, or using set image. kubectl edit deployment updates the live config. kubectl apply -f update.yaml applies a new manifest. kubectl set image updates the image directly. kubectl delete and create would cause downtime.

Answer

kubectl delete deployment frontend and then create a new deployment.

Answer

kubectl rollout undo deployment/frontend

Question 11

Refer to the exhibit. Based on the YANG model snippet, what is the data type of the 'mask' leaf?

Accepted Answer

inet:ipv4-prefix-length. The 'mask' leaf is defined with the type 'inet:ipv4-prefix-length', which represents a decimal integer from 0 to 32 indicating the number of leading 1 bits in the subnet mask (e.g., 24 for /24). This is the correct data type for a prefix length in YANG models, not an IPv4 address or a generic string.

Answer

inet:ipv4-address

Answer

uint8

Answer

string

Question 12

A DevOps team is developing a CI/CD pipeline for a microservices application that uses Cisco NSO (Network Services Orchestrator) for network configuration. The application code is stored in a Git repository. The pipeline must automatically trigger a test suite when a pull request is merged to the main branch, but only if the tests pass, then deploy to a staging environment. The team is using Jenkins. A junior engineer suggests using a single Jenkinsfile with a declarative pipeline that includes all stages. However, a senior engineer notes that the pipeline should be designed for reusability and maintainability, especially as the number of microservices grows. Which approach best meets these requirements?

Accepted Answer

Use shared libraries to define common stages like testing and deployment, and reference them in each microservice's Jenkinsfile.. Shared libraries in Jenkins allow common pipeline logic (e.g., testing and deployment stages) to be defined once and reused across multiple microservices. This promotes reusability and maintainability, as changes to the shared library automatically propagate to all Jenkinsfiles, reducing duplication and simplifying updates as the number of microservices grows.

Answer

Create separate Jenkinsfiles for each microservice and call them from a main pipeline using the "build" step.

Answer

Use a single scripted pipeline that uses "parallel" for microservices and "stage" for testing and deployment.

Answer

Use a single declarative pipeline with all stages defined in the Jenkinsfile and use "when" conditions to control execution.

Question 13

Which TWO statements are true about VXLAN? (Choose two.)

Accepted Answer

VXLAN encapsulates Ethernet frames in UDP packets. VXLAN (Virtual Extensible LAN) encapsulates the original Layer 2 Ethernet frame inside a UDP packet (typically UDP destination port 4789). This allows the Layer 2 frame to be transported over a Layer 3 IP network, enabling network virtualization and overlay networking without requiring changes to the physical underlay.

Answer

VXLAN requires MPLS in the underlay

Answer

VXLAN uses IP-in-IP encapsulation

Answer

VXLAN operates at Layer 2 only

Question 14

An application needs to discover the MAC address of another device on the same local network. Which protocol does it use?

Accepted Answer

ARP. ARP (Address Resolution Protocol) is used to map an IP address to a MAC address on a local network.

Answer

DNS

Answer

ICMP

Answer

DHCP

Question 15

Which data format is most commonly used in REST API requests and responses in modern network automation?

Accepted Answer

JSON. JSON (JavaScript Object Notation) is the most commonly used data format in REST API requests and responses for modern network automation because it is lightweight, language-agnostic, and natively supported by most programming languages and network devices. REST APIs typically use JSON over HTTP due to its ease of parsing, compact structure, and alignment with web development practices, making it the de facto standard for exchanging structured data in automation workflows like those with Cisco NSO, Ansible, or Python scripts.

Answer

YAML

Answer

XML

Answer

CSV