200-901 Practice Test 31 — 15 Questions

Question 1

Which three actions can an EEM applet perform when triggered? (Choose three.)

Accepted Answer

Execute a CLI command. EEM (Embedded Event Manager) applets can execute CLI commands when triggered by an event. This allows automation of operational tasks such as configuration changes or troubleshooting commands without manual intervention.

Answer

Modify a YANG data model

Answer

Create a new VLAN

Question 2

In a microservices architecture, which of the following is a key characteristic compared to a monolithic architecture?

Accepted Answer

Services communicate via lightweight protocols such as HTTP/REST.. In a microservices architecture, services are independently deployable and typically communicate over lightweight protocols such as HTTP/REST or messaging queues. This contrasts with monolithic architectures where components are tightly coupled and communicate via internal method calls.

Answer

Changes require rebuilding the entire application.

Answer

The entire application is deployed as a single unit.

Answer

All services share the same database.

Question 3

In a Kubernetes deployment, a developer needs to expose a set of pods internally within the cluster on a stable IP address. The pods are stateless and serve HTTP traffic. Which Service type should be used?

Accepted Answer

ClusterIP. ClusterIP exposes the service on a cluster-internal IP, making it reachable only within the cluster. NodePort and LoadBalancer expose externally. ExternalName maps to an external DNS name.

Answer

LoadBalancer

Answer

ExternalName

Answer

NodePort

Question 4

A developer needs to send a message to a specific room in Webex using the API. What is the correct endpoint and required body parameter for the room destination?

Accepted Answer

POST /v1/messages with roomId parameter. To send a message to a Webex room, use POST /v1/messages with the roomId parameter to specify the target room.

Answer

POST /v1/messages with toPersonEmail parameter

Answer

POST /v1/memberships with roomId

Answer

POST /v1/rooms with message text

Question 5

A developer is using NX-API on a Cisco Nexus switch to execute CLI commands via JSON. Which endpoint and method should be used?

Accepted Answer

POST /ins with JSON body. NX-API on Cisco Nexus switches exposes a REST endpoint at /ins that accepts POST requests with a JSON body containing the CLI commands to execute. The JSON body includes parameters such as 'ins_api' with 'version', 'type' (cli_show), 'chunk', 'sid', 'input' (the command), and 'output_format' (json). This is the standard way to run show commands programmatically via NX-API.

Answer

GET /restconf/data/Cisco-NX-OS-device:cli

Answer

POST /api/cli with XML body

Answer

GET /ins?cmd=show version

Question 6

Which THREE of the following are true about HTTP/2 compared to HTTP/1.1? (Select three.)

Accepted Answer

Header compression using HPACK. Option C is correct because HTTP/2 introduces HPACK (RFC 7541), a header compression scheme that uses static and dynamic tables plus Huffman encoding to shrink repetitive header fields, which HTTP/1.1 sends uncompressed as plain text on every request. Option D is correct because HTTP/2 adds server push, allowing the server to proactively send resources (e.g., via PUSH_PROMISE frames) that the client will likely need, a feature absent from HTTP/1.1. Option E is correct because HTTP/2 multiplexes many concurrent streams over one TCP connection using binary framing, eliminating HTTP/1.1's head-of-line blocking at the request level and its need for multiple parallel connections. Option A is wrong because HTTP/2 is a binary protocol, whereas HTTP/1.1 is text-based. Option B is wrong because HTTP/2 does not mandate TLS; it can run over cleartext TCP (h2c), although browsers only implement it over TLS.

Answer

Text-based protocol

Answer

Requires TLS/SSL encryption

Question 7

A Python developer is working on a microservices project where one service needs to communicate with another service that exposes a GraphQL API. Which THREE statements about GraphQL compared to REST are accurate? (Choose three.)

Accepted Answer

GraphQL allows clients to request exactly the fields they need.. Option A is correct because GraphQL's core advantage over REST is that the client specifies the exact fields it wants in a single query, avoiding over-fetching and under-fetching of data. Option C is correct because a GraphQL API is defined by a strongly typed schema (SDL) that declares types, queries, mutations, and subscriptions, enabling validation and introspection. Option E is correct because GraphQL operations (queries and mutations) are typically sent as a single HTTP POST request to one endpoint with a JSON body containing the query string. Option B is incorrect because GraphQL is an API query language and runtime, not a database query language like SQL; it is datastore-agnostic. Option D is incorrect because GraphQL normally exposes a single endpoint (e.g., /graphql) rather than multiple resource-specific endpoints as REST does.

Answer

GraphQL is a database query language.

Answer

GraphQL typically uses multiple endpoints for different resources.

Question 8

A network engineer is troubleshooting a connectivity issue between two hosts in different VLANs on the same switch. The hosts are in VLAN 10 and VLAN 20, respectively. The switch has an SVI for each VLAN and IP routing is enabled. Which command should be used to verify that the switch is forwarding traffic between the VLANs?

Accepted Answer

show ip route. 'show ip route' displays the switch's routing table, which contains the directly connected subnets for VLAN 10 and VLAN 20 (via their SVIs) and any learned routes. Since IP routing is enabled, the switch uses this table to make forwarding decisions between VLANs. Verifying that both VLAN subnets appear in the routing table confirms that the switch can route traffic between them.

Answer

show interfaces trunk

Answer

show vlan

Answer

show mac address-table

Question 9

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. A LoadBalancer service type provisions an external load balancer through the cloud provider, assigning a stable public IP that distributes traffic across the backing pods. This directly satisfies both requirements: external accessibility via a stable IP and load balancing across pod replicas. NodePort exposes a static port on each node but does not provide a stable single IP or built-in load balancing.

Answer

NodePort

Answer

ClusterIP

Answer

ExternalName

Question 10

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 a host port to a container port using the format host:container. Since the host should listen on 8080 and the application inside the container listens on 80, the correct mapping is -p 8080:80. The -d flag runs the container detached, which is appropriate for a web service.

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 11

A Webex bot needs to send a message to a room. The bot has the room ID. Which API endpoint should be used, and what is the correct HTTP method?

Accepted Answer

POST /v1/messages. The Webex Teams API uses POST /v1/messages to create and send a new message to a room. The request body must include the roomId and either text or markdown. This is the standard endpoint for sending messages, and it returns a 200 OK with the message details upon success.

Answer

PUT /v1/messages/{messageId}

Answer

GET /v1/messages

Answer

POST /v1/rooms

Question 12

A NETCONF manager sends a get-config request to a Cisco device and receives the above reply. The automation script expected the interface to be enabled. Which of the following is the best course of action to remediate the issue?

Accepted Answer

Send an edit-config request with true for the interface. NETCONF uses the edit-config operation to modify device configuration programmatically. Since the automation script detected that the interface is disabled (enabled state is false), sending an edit-config request with true for that interface directly remediates the issue by setting the operational state to enabled, aligning with the expected state without manual intervention.

Answer

Send an rpc to reboot the device

Answer

Use CLI to enable the interface manually

Answer

Send a get request again

Question 13

Which THREE of the following are characteristics of NETCONF? (Select THREE)

Accepted Answer

Uses SSH as the transport protocol. NETCONF is defined in RFC 6241 and uses SSH as its mandatory transport protocol (port 830), so option A is correct because SSH provides the secure, connection-oriented session over which NETCONF messages are exchanged. Option D is correct because NETCONF encodes its protocol operations as XML-based RPC elements (for example, and ), making XML the required encoding for the protocol's messages. Option E is correct because NETCONF defines standard operations such as to retrieve configuration data and to modify it, which are core to its configuration-management capabilities. Option B is incorrect because HTTP is the transport used by RESTCONF, not NETCONF. Option C is incorrect because NETCONF uses XML encoding, whereas JSON encoding is a feature of RESTCONF (and other YANG-based interfaces), not of NETCONF itself.

Answer

Uses HTTP as the transport protocol

Answer

Supports JSON encoding for data

Question 14

A network engineer wants to automate a configuration change on a Cisco IOS XE device when a specific syslog message appears. Which tool should they use?

Accepted Answer

EEM applet configured to match the syslog pattern and execute CLI commands. EEM (Embedded Event Manager) is a built-in Cisco IOS XE feature that allows the device to react to local events, including syslog messages. An EEM applet can be configured with an event syslog pattern to match a specific syslog message and an action to execute CLI commands, enabling automated configuration changes directly on the device. This is the most direct and native way to trigger a configuration change based on a syslog message without external dependencies.

Answer

RESTCONF with a Python script polling the device

Answer

SNMP trap receiver

Answer

NETCONF with a YANG-based notification subscription

Question 15

A DevOps team is automating network configuration using Ansible. They want to push a new VLAN configuration to a switch but ensure that only one switch is updated at a time to avoid network disruption. Which Ansible strategy or feature should they use?

Accepted Answer

Set 'serial: 1' in the playbook.. Setting `serial: 1` in an Ansible playbook forces the play to execute against only one host at a time, even if the play targets multiple switches. This ensures that VLAN configuration is pushed to exactly one switch before moving to the next, preventing network disruption from simultaneous changes.

Answer

Use 'strategy: free' to manage execution order.

Answer

Set 'forks: 1' in the playbook.

Answer

Use 'throttle: 1' on each task.