200-901 Practice Exam 51 — 20 Questions

Question 1

An application uses Cisco DNA Center APIs and needs to receive notifications when a new device is added. Which DNA Center API category should be used to set up event-driven notifications?

Accepted Answer

Platform. The Platform API category includes event notifications and task management features.

Answer

Change your network

Answer

Know your network

Answer

Run your network

Question 2

Which TWO of the following are characteristics of the YANG data modeling language that make it suitable for network automation? (Select two)

Accepted Answer

YANG defines data types and constraints. YANG is a data modeling language that defines the structure, syntax, and semantics of configuration and state data, including explicit data types (e.g., string, uint32) and constraints (e.g., range, pattern, mandatory). This strict typing and validation ensure that network devices receive well-formed data, reducing errors in automation workflows.

Answer

YANG is human-readable only

Answer

YANG is a markup language like XML

Answer

YANG supports both configuration and operational state data

Question 3

Which Git command is used to switch to an existing branch named 'feature-x' and update the working directory?

Accepted Answer

git checkout feature-x. `git checkout feature-x` is the traditional Git command that switches the HEAD reference to the existing branch 'feature-x' and updates the working directory to match that branch's commit history. This command performs both the branch switch and the working tree update in one operation, which is the core requirement of the question.

Answer

git merge feature-x

Answer

git branch feature-x

Answer

git switch -c feature-x

Question 4

Which HTTP method is considered both safe and idempotent?

Accepted Answer

GET. GET is both safe and idempotent according to HTTP semantics (RFC 7231). Safe means it must not cause side effects on the server, and idempotent means multiple identical requests produce the same result as a single request. GET is designed solely for retrieval of a resource, so it satisfies both properties.

Answer

POST

Answer

PUT

Answer

PATCH

Answer

DELETE

Question 5

A developer needs to share a Docker image with a colleague. They decide to push the image to a registry. Which Docker command pushes an image to a registry?

Accepted Answer

docker push my-image:latest. docker push uploads a local image to a registry. docker pull downloads. docker push requires the image to be tagged with the registry URL.

Answer

docker export my-image:latest

Answer

docker commit my-image:latest

Answer

docker pull my-image:latest

Question 6

A Kubernetes environment has multiple teams sharing the same cluster. One team wants to deploy applications without interfering with other teams' resources. Which Kubernetes resource should be used to isolate the team's resources?

Accepted Answer

Namespace. Namespaces provide logical isolation within a cluster. Each team can have its own namespace with separate policies and resource quotas.

Answer

ServiceAccount

Answer

NodePort

Answer

ConfigMap

Question 7

A developer runs the command: docker run -d -p 8080:80 --name web nginx. Which of the following best describes what happens?

Accepted Answer

The container runs in detached mode, and host port 8080 is mapped to container port 80.. -d runs container detached, -p maps host port 8080 to container port 80, --name assigns name 'web', and nginx is the image.

Answer

The container runs in interactive mode, and port 8080 is exposed but not published.

Answer

The container is removed after stopping, and port mapping is automatic.

Answer

The container runs in the foreground, and port 80 on the host is mapped to port 8080 in the container.

Question 8

In a docker-compose.yaml file, which key is used to define the container image to be built from a Dockerfile in the current directory?

Accepted Answer

build. The 'build' key specifies the path to the Dockerfile context; 'image' specifies a pre-built image from a registry.

Answer

dockerfile

Answer

image

Answer

context

Question 9

A Kubernetes administrator wants to use kubectl to troubleshoot a pod named 'my-pod' that is not starting. Which TWO commands are useful? (Choose two.)

Accepted Answer

kubectl describe pod my-pod. kubectl describe pod my-pod shows detailed information including events and container statuses. kubectl logs my-pod shows container logs. The other commands are for different resources or abstract actions.

Answer

kubectl get deployment my-deployment

Answer

kubectl rollout status deployment my-deployment

Answer

kubectl delete pod my-pod

Question 10

A Kubernetes pod runs two containers that need to share a filesystem. Which volume type should be used to enable file sharing between the containers within the same pod?

Accepted Answer

emptyDir. An emptyDir volume is created empty when a pod is scheduled and can be mounted by multiple containers in the same pod, allowing them to share files.

Answer

configMap

Answer

hostPath

Answer

persistentVolumeClaim

Question 11

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

Accepted Answer

NodePort. NodePort exposes on each node's IP, LoadBalancer creates external load balancer, Ingress provides HTTP routing. ClusterIP is internal only, ExternalName maps to DNS record.

Answer

ExternalName

Answer

ClusterIP

Question 12

A company deploys a microservice using Kubernetes. The service must be accessible externally via a stable IP address and load-balanced across pods. Which Service type should be used?

Accepted Answer

LoadBalancer. LoadBalancer exposes the service externally using a cloud provider's load balancer. ClusterIP is internal only, NodePort exposes on each node's IP, ExternalName maps to external DNS.

Answer

NodePort

Answer

ClusterIP

Answer

ExternalName

Question 13

A developer needs to share a Docker image built from a Dockerfile with team members. Which command correctly builds the image and tags it as 'myapp:v1'?

Accepted Answer

docker build --tag myapp:v1 .. Both the `--tag` flag and the `-t` shorthand are valid options for tagging a Docker image during build. `docker build --tag myapp:v1 .` and `docker build -t myapp:v1 .` are equivalent commands that build the image from the current directory and tag it as myapp:v1.

Answer

docker build . --name myapp:v1

Question 14

Which Docker command is used to view the logs of a running container in real-time?

Accepted Answer

docker logs -f. docker logs -f follows the log output of a container, similar to tail -f.

Answer

docker inspect

Answer

docker ps -a

Answer

docker exec -it

Question 15

A Docker container running a web application needs to be accessible on the host's port 8080. The application inside the container listens on port 80. Which docker run command achieves this?

Accepted Answer

docker run -d -p 8080:80 myapp. The -p flag maps host ports to container ports. The correct syntax is -p :.

Answer

docker run -d --expose 80 -p 8080 myapp

Answer

docker run -d -p 80:8080 myapp

Answer

docker run -d -P 8080:80 myapp

Question 16

A developer is writing a web application and needs to prevent SQL injection attacks. Which coding practice is most effective?

Accepted Answer

Use parameterized queries with prepared statements. Parameterized queries separate SQL logic from data, preventing attackers from injecting malicious SQL. Input validation is also important but not a direct prevention of SQL injection.

Answer

Validate input with regex to allow only alphanumeric characters

Answer

Use stored procedures exclusively

Answer

Escape all user input with htmlspecialchars

Question 17

In the OSI model, which layer is responsible for logical addressing and routing of packets between networks?

Accepted Answer

Layer 3 (Network). Layer 3 (Network layer) handles IP addressing and routing decisions.

Answer

Layer 1 (Physical)

Answer

Layer 4 (Transport)

Answer

Layer 2 (Data Link)

Question 18

Refer to the exhibit. A Python script using RESTCONF sends a GET request to retrieve the interface configuration. The response is shown. What is the VLAN assigned to GigabitEthernet1/0/1?

Accepted Answer

10. (VLAN 10) because the RESTCONF GET response shows the native VLAN for GigabitEthernet1/0/1 is set to 10. In Cisco IOS-XE, the native VLAN is the VLAN assigned to an interface when it is in access mode, and the response explicitly includes the 'native-vlan' field with a value of 10 under the 'Cisco-IOS-XE-native:interface' hierarchy.

Answer

1

Answer

100

Answer

20

Question 19

Which TWO of the following protocols use UDP as the transport layer protocol? (Choose two.)

Accepted Answer

DNS. DNS and DHCP use UDP because they are lightweight and can tolerate some loss. HTTP uses TCP, and SMTP uses TCP.

Answer

HTTP

Answer

SMTP

Answer

SSH

Question 20

Which TWO of the following are southbound protocols in SDN?

Accepted Answer

NETCONF. OpenFlow and NETCONF are southbound protocols used between controller and network devices.

Answer

OSPF

Answer

SNMP

Answer

REST