350-901: Developing Applications using Cisco Core Platforms and APIs (DEVCOR)

Question #: 181
Topic #: 1
Refer to the exhibit. What is the output of this IOS-XE configuration program?

A. interface operational status in IPv6 addresses
B. interface administrative status in IPv4 addresses
C. interface operational status in IPv4 addresses
D. interface administrative status in IPv6 addresses

Selected Answer: B

Question #: 182
Topic #: 1
Which database type should be used to store data received from model-driven telemetry?

A. BigQuery database
B. Time series database
C. NoSQL database
D. PostgreSQL database

Selected Answer: B

Question #: 183
Topic #: 1
DRAG DROP –

Refer to the exhibit. Drag and drop parts of the URL from the left onto the item numbers on the right that match the missing sections in the exhibit to create the appropriate RESTCONF URL to query the VLAN configuration given this YANG model. Not all URL parts are used.
Select and Place:

Suggestion Answer:

Question #: 184
Topic #: 1
A heterogeneous network of vendors and device types needs automating for better efficiency and to enable future automated testing. The network consists of switches, routers, firewalls and load balancers from different vendors, however they all support the NETCONF/RESTCONF configuration standards and the YAML models with every feature the business requires. The business is looking for a buy versus build solution because they cannot dedicate engineering resources, and they need configuration diff and rollback functionality from day 1.
Which configuration management for automation tooling is needed for this solution?

A. Ansible
B. Ansible and Terraform
C. NSO
D. Terraform
E. Ansible and NSO

Selected Answer: C

Question #: 185
Topic #: 1
An automated solution is needed to configure VMs in numerous cloud provider environments to connect the environments to an SDWAN. The SDWAN edge VM is provided as an image in each of the relevant clouds and can be given an identity and all required configuration via cloud-init without needing to log into the VM once online.
Which configuration management and/or automation tooling is needed for this solution?

A. Ansible
B. Ansible and Terraform
C. NSO
D. Terraform
E. Ansible and NSO

Selected Answer: B

Question #: 186
Topic #: 1
What are two advantages of using model-driven telemetry, such as gRPC, instead of traditional telemetry gathering methods? (Choose two.)

A. all data is ad-hoc
B. decentralized storage of telemetry
C. efficient use of bandwidth
D. no overhead
E. continuous information with incremental updates

Selected Answer: CE

Question #: 187
Topic #: 1
What is a consideration for using gRPC as the model-driven telemetry protocol on a Cisco IOS XE device?

A. works in call-out mode
B. XML-based transmission format
C. works in dial-out mode
D. human-readable transmission format

Selected Answer: C

Question #: 188
Topic #: 1
DRAG DROP –
A Python application is being written to run inside a Cisco IOS XE device to assist with gathering telemetry data. Drag and drop the elements of the stack from the left onto the functions on the right to collect and display the telemetry streaming data.
Select and Place:

Suggestion Answer:

Question #: 189
Topic #: 1
What is the gRPC Network Management Interface protocol?

A. a unified management protocol for streaming telemetry and database logging
B. a configuration management protocol for monitoring
C. a protocol for configuration management and streaming telemetry
D. a logging protocol used across database servers

Selected Answer: C

Question #: 190
Topic #: 1
Which two gRPC modes of model-driven telemetry are supported on Cisco IOS XE Software? (Choose two.)

A. dial-in
B. dial-out
C. call-in
D. call-out
E. passive

Selected Answer: AB

Question #: 191
Topic #: 1
A heterogeneous network of vendors and device types needs automating for better efficiency and to enable future automated testing. The network consists of switches, routers, firewalls, and load balancers from different vendors; however, they all support the NETCONF/RESTCONF configuration standards and the
YANG models with every feature the business requires. The business is looking for a buy versus build solution because they cannot dedicate engineering resources, and they need configuration diff and rollback functionality from day 1.
Which configuration management or automation tooling is needed for this solution?

A. PyATS
B. AppDynamics
C. NSO
D. Puppet

Selected Answer: C

Question #: 192
Topic #: 1
Refer to the exhibit. Which RESTCONF verb changes the GigabitEthernet2 interface from 192.168.100.1/24 to 10.10.10.1/24?

A. POST
B. PATCH
C. GET
D. HEAD

Selected Answer: B

Question #: 193
Topic #: 1
DRAG DROP –

Refer to the exhibit above and click on the resource tabs in the top left corner to view resources to help with this question. Drag and drop the code snippets from the left onto the item numbers on the right that match the missing sections in the exhibit to complete the cURL script that will use RESTCONF to update an interface on a Cisco IOS XE device.
Select and Place:

Suggestion Answer:

Question #: 194
Topic #: 1
Refer to the exhibit. An engineer needs to change the IP address via RESTCONF on interface GigabitEthemet2. An error message is received when the script is run.
Which amendment to the code will result in a successful RESTCONF action?

A. Change POST to PATCH
B. Issue a DELETE before POST
C. Issue a DELETE before PATCH
D. Change POST to GET

Selected Answer: A

Question #: 195
Topic #: 1
DRAG DROP –
A network engineer needs to retrieve interface data using the Cisco IOS XE YANG Model. Drag and drop the components from the bottom onto the box where the code is missing to complete the RESTCONF URI. Not all options are used.
Select and Place:

Suggestion Answer:

Question #: 196
Topic #: 1
An automated solution is needed to configure VMs in numerous cloud provider environments to connect the environments to an SDWAN. The SDWAN edge VM is provided as an image, in each of the relevant clouds it is given an identity and all required configuration via cloud-init without needing to log into the VM once online. Which configuration management automation tool is needed for this solution?

A. Terraform
B. HyperFlex
C. Intersight
D. Ansible

Selected Answer: A

Question #: 197
Topic #: 1
A developer is deploying an application to automate the configuration and management of Cisco network switches and routers. The application must use REST
API interface to achieve programmability. The security team mandates that the network must be protected against DDoS attacks. What mitigates the attack without impacting genuine requests?

A. IP address filtering at the application layer
B. traffic routing on the network perimeter
C. API rate limiting at the application layer
D. firewall on the network perimeter

Selected Answer: C

Question #: 198
Topic #: 1
A developer releases a new application for network automaton of Cisco devices deployed in a local data center. The application utilizes complex design patterns such as microservices that host multiple third-party libraries and programming languages. The development must be simplified by implementing an observability- driven development lifecycle. Which two considerations must be taken to meet the requirements? (Choose two.)

A. which monitoring tools to use
B. identifying customer priorities
C. relevant metrics to expose
D. description of low-level errors
E. which KPIs to monitor

Selected Answer: CE

Question #: 199
Topic #: 1
Which data encoding format uses gRPC by default for serializing structured sets of information?

A. XML
B. JSON
C. YAML
D. Protobuf

Selected Answer: D

Question #: 200
Topic #: 1
DRAG DROP
–

Drag and drop the code from the bottom onto the box where the code is missing to retrieve a summary of physical compute resources. The collected information about the compute resources will be presented in a dashboard to be developed for device monitoring purposes. Not all snippets are used.

Suggestion Answer:

Question #: 201
Topic #: 1
A developer in a team of distributed authors is working on code in an isolated Git branch named ‘update1a2b3456789’. The developer attempts to merge the new code with a branch named ‘dvcapp9a8b7654321’ however the merge operation encounters a conflict error during the process. Which Git command must the developer use to exit from the merge process and return the branch to the previous state?

A. git abort –status
B. git abort –merge
C. git merge –exit
D. git merge –abort

Selected Answer: D

Question #: 202
Topic #: 1
Where must the data be encrypted to ensure end-to-end encryption when using an API?

A. on the server that stores the data
B. on the end device after a request is received
C. on the device that consumes the API
D. on the source device before transmission

Selected Answer: D

Question #: 203
Topic #: 1
Refer to the exhibits. An engineer writes a script to retrieve data from a REST API and must build support for cases where the response that contains data from the server may take a longer time than normal. Which code must be added to the snippet where the code is missing to catch such a timeout?

A. requests.exceptions.HTTPError
B. requests.exceptions.DataTimeout
C. requests.exceptions.ConnectTimeout
D. requests.exceptions.ReadTimeout

Selected Answer: C

Question #: 204
Topic #: 1
DRAG DROP
–

A developer is creating a Python script to analyze errors during REST API call operations. The script will be used with Cisco solutions and devices. Drag and drop the code from the bottom to the box where the code is missing to implement control flow for handling unrecoverable REST API calls. Not all options are used.

Suggestion Answer:

Question #: 205
Topic #: 1
A developer has issued the git add file1 file2 test.py command to add three files for the next commit, but then decides to exclude test.py from this commit. Which command needs to be used to exclude test.py from this commit but keep the rest of the files?

A. git stash — file1 file 2
B. git clean — test.py
C. git checkout — file1 file2
D. git reset — test.py

Selected Answer: D

Question #: 206
Topic #: 1
DRAG DROP
–

Drag and drop the code from the bottom onto the box where the code is missing on the Dockerfile to containerize an application that listens on the specified TCP network port at runtime. Not all options are used.

Suggestion Answer:

Question #: 207
Topic #: 1
Refer to the exhibit. Recently, users have reported problems logging into an application with their usernames and passwords. The logs have captured an authentication attempt. Based on the messages and errors contained, what is the cause of the problem?

A. There is a time synchronization issue between the application and LDAP.
B. The LDAP server used for authentication fails to respond to connection requests.
C. The sign-in redirection is sending clients to the wrong server for SSO.
D. Users are providing incorrect credentials when logging in.

Selected Answer: B

Question #: 208
Topic #: 1
DRAG DROP
–

Refer to the exhibit. Drag and drop the code from the bottom onto the box where the code is missing to construct a Python script that prints a message if the Cisco DNA Center wireless network health for a site is not greater than 90%. The information is collected from the wireless network devices using GET method of REST API. Not all options are used.

Suggestion Answer:

Question #: 209
Topic #: 1
DRAG DROP
–

Drag and drop the code from the bottom onto the box where the code is missing to configure a Python script that uses RESTCOMF to add an IP address and subnet mask to an interface. Not all options are used.

Suggestion Answer:

Question #: 210
Topic #: 1
Two Elasticsearch database servers use bidirectional asynchronous data replication. Both servers accept writes from clients. The design must meet these requirements:
• The cluster survives if a fault occurs that causes the network connection to go down between nodes.
• The data remains consistent if communication between nodes fails.
• The data is spread evenly across all nodes in the cluster.

Which design approach must be used to meet the requirements?

A. Set the initial voting configuration to force a specific node as the master.
B. Set the minimum_master_nodes to 2 in the configuration.
C. Scale the master nodes down to a single node.
D. Add a third cluster node to provide majority votes.

Selected Answer: D

Question #: 211
Topic #: 1
What securely stores and encrypts the API keys and tokens that are used for an application deployment?

A. GitHub
B. ITSM
C. Artifactory
D. Vault

Selected Answer: D

Question #: 212
Topic #: 1
DRAG DROP
–

Drag and drop the code from the bottom onto the box where the code is missing to construct a UCS XML API request to generate two service profiles from the template org-root/ls-service-template. Not all options are used.

Suggestion Answer:

Question #: 213
Topic #: 1
DRAG DROP
–

Refer to the exhibit. Drag and drop the code from the bottom onto the box where the code is missing to construct a Python script that will retrieve location data. Not all options are used.

Suggestion Answer:

Question #: 214
Topic #: 1
Refer to the exhibit. An engineer needs to implement REST API error handling when a timeout or rate limit scenario is present. Which code snippet must be placed into the blank in the code to complete the API request?

A.
B.
C.
D.

Selected Answer: D

Question #: 215
Topic #: 1
DRAG DROP
–

Drag and drop the components from the left into the order on the right to create the flow of the three-legged OAuth2.

Suggestion Answer:

Question #: 216
Topic #: 1
A development team is looking for a tool to automate configurations across the infrastructure. The tool must have these characteristics:
• written in Python
• define playbooks for intent
• stateless
• imperative

Which tool meets these requirements?

A. Ansible
B. Netmiko
C. NCM
D. Puppet

Selected Answer: A

Question #: 217
Topic #: 1
What is a benefit of implementing a Cl pipeline?

A. decreases external dependencies
B. enables a faster feedback loop
C. enforces version control
D. ensures that tests are written before code is written

Selected Answer: B

Question #: 218
Topic #: 1
Refer to the exhibit. Which URL retrieves the errors in the GigabitEthernet1 interface?

A.
B.
C.
D.

Selected Answer: C

Question #: 219
Topic #: 1
Refer to the exhibit. Which command results in a detached HEAD scenario?

A. git checkout 5af25b
B. git checkout master
C. git checkout log -2
D. git checkout Branch-5

Selected Answer: A

Question #: 220
Topic #: 1
DRAG DROP
–

Refer to the exhibit. Drag and drop the components from the Oauth2 authorization protocol flow on the left onto the letter that matches the location in the exhibit.

Suggestion Answer:

Question #: 221
Topic #: 1
DRAG DROP
–

Drag and drop the code from the bottom onto the box where the code is missing to create a new IKEv2 policy. Not all options are used.

Suggestion Answer:

Question #: 222
Topic #: 1
DRAG DROP
–

Drag and drop the code from the bottom onto the box where the code is missing to create a Webex meeting by using the Webex API. Not all options are used.

Suggestion Answer:

Question #: 223
Topic #: 1
Refer to the exhibit. A network engineer created a simple Python Flask application but must incorporate a CSRF token. Which code snippet must be added in the blank in the script to manually incorporate the token?

A. _csrf_token” value=”{{ csrf_token() }}
B. _access_token” value=”{{ csrf_token }}
C. _csrf_token” value=”{{ csrf_grant() }}
D. _xss_token” value=”{{ csrf_token }}

Selected Answer: A

Question #: 224
Topic #: 1
How should logs for an application be created?

A. Use fault-tolerant protocols.
B. Monitor for backlogs and outages.
C. Use a standard and easily configurable logging framework.
D. Filter sensitive data before transmitting logs.

Selected Answer: D

Question #: 225
Topic #: 1
DRAG DROP
–

Drag and drop the code from the bottom onto the box where the code is missing to permit network traffic between 10.0.0.0/8 and all other networks on port 80 for a Cisco Nexus 9000 switch by using the Puppet module. Not all options are used.

Suggestion Answer:

Question #: 226
Topic #: 1
DRAG DROP
–

Refer to the exhibit. Drag and drop the code from the bottom onto the box where the code is missing to query the last 10 Bluetooth clients seen by APs in their network using the Meraki Dashboard API. Not all options are used.

Suggestion Answer:

Question #: 227
Topic #: 1
Refer to the exhibit. A Docker swarm service is currently running in a local data center. The service is hosting an HTML website. If the container fails, then the service becomes unavailable. The design must meet these requirements:
• The service must be highly available and resilient against a data center outage.
• The service must be accessible from a single URL.
• The HTTP session must remain on the server from which the original request was sent.
• Failure of the server must force the client to reconnect.

Which two design approaches must be used to meet the requirements? (Choose two.)

A. Create another node in the swarm cluster to scale the service across the nodes over two replicas.
B. Scale the Docker swarm service to 2 and set endpoint-mode to DNSRR instead of the default value of VIP.
C. Configure an external load balancer to route requests to the swarm service by using session persistence.
D. Configure a routing mesh to route requests to the swarm service by using NAT on the network side.
E. Create another swarm cluster within a data center and deploy a secondary instance of the service.

Selected Answer: AC

Question #: 228
Topic #: 1
Refer to the exhibit. A developer created a Python script to retrieve information about Meraki devices in a local network deployment. After requesting a security review of the code, the security analyst has observed poor secret storage practices. What is the appropriate secret storage approach?

A. Set an OS environment variable for MER_API_KEY to the API key before running the code and no longer set MER_API_KEY within the code.
B. Leverage an external secret vault to retrieve MER_API_KEY and set the vault key as an OS environment variable before running the code.
C. Set the Base64 encoded version of the API key as MER_API_KEY in the code and Base64 decode before using in the header.
D. Leverage an external secret vault to retrieve MER_API_KEY and embed the vault key as a new variable before running the code.

Selected Answer: B

Question #: 229
Topic #: 1
DRAG DROP
–

Drag and drop the code from the bottom onto the box where the code is missing to construct a contact tracing application that dynamically returns all the Bluetooth clients on a given Meraki network. Not all options are used.

Suggestion Answer:

Question #: 230
Topic #: 1
DRAG DROP
–

Drag and drop the code from the bottom onto the box where the code is missing to construct a Puppet manifest to configure DNS. Not all options are used.

Suggestion Answer:

Question #: 231
Topic #: 1
DRAG DROP
–

Drag and drop the code from the bottom onto the box where the code is missing to enable an SSID by using the Cisco Meraki Dashboard API. Not all options are used.

Suggestion Answer:

Question #: 232
Topic #: 1
An architect must optimize traffic that targets a popular API endpoint. Currently, the application downloads a large file hourly, but often the file is unchanged and the download causes unnecessary load and delays. Which cURL command must be used to determine the last modified date of the file and to optimize the API usage?

A. curl -H ‘Cache-Control: no-cache’ request
B. curl HEAD request
C. curl –silent request
D. curl GET request

Selected Answer: D

Question #: 233
Topic #: 1
DRAG DROP
–

Drag and drop the operations from the left into the order on the right to create a web dashboard that displays Cisco DNA Center data for an organization.

Suggestion Answer:

Question #: 234
Topic #: 1
Which function does Fluentd fulfill for application logging in Kubernetes?

A. monitoring and log visualization
B. logging agent for distribution
C. messaging/queueing infrastructure
D. backend time series database storage

Selected Answer: A

Question #: 235
Topic #: 1
Refer to the exhibit. Which action resolves the error for the GitLab CI/CD pipeline execution?

A. Install the missing python libraries via pip3.
B. Download the correct artifacts by specifying them in GitLab.
C. Use the python.3.9. 0a4-alpine3.10 Docker image.
D. Add the absolute path to the python3 executable.

Selected Answer: D

Question #: 236
Topic #: 1
DRAG DROP
–

A developer is creating a Python function that adds network engineers to a Webex room to troubleshoot after a monitoring alert. Drag and drop the code from the bottom onto the box where the code is missing in the Python function to add the engineers to the room. Not all options are used.

Suggestion Answer:

Question #: 237
Topic #: 1
How does the use of release packaging allow dependencies to be effectively managed during deployments?

A. removal of release units if they have issues in testing
B. dependencies are tested after the release is deployed
C. designed to prevent any dependencies between release units
D. dependencies are staggered between multiple releases

Selected Answer: C

Question #: 238
Topic #: 1
An application requires SSL certificates signed by an intermediate CA certificate. The .crt files must be available to the application:
• The root CA certificate is root_certificate.crt.
• The intermediate CA certificate is intermediate_certificate.crt.
• The application-specific SSL certificate is crl_certificate.crt.

Which Bash command outputs the certificate bundle as a .pem file?

A. cat intermediate_certificate.crt root_certificate.crt >
certificate_bundle.pem
B. cat crl certificate.crt intermediate certificate.crt
root certificate.crt > certificate bundle.pem
C. cat root certificate.crt intermediate certificate.crt
crl certificate.crt > certificate bundle.pem
D. cat root certificate.crt intermediate certificate.crt >
certificate bundle.pem

Selected Answer: B

Question #: 239
Topic #: 1
Refer to the exhibits. An application is created to serve the needs of an enterprise. Slow performance now impacts certain API calls, and the application design lacks observability. Which two commands improve observability and provide an output that is similar to the sample output? (Choose two.)

A. with dnac-tracer3.start_span(‘dnac-api-calls’) as span:
B. dnac-tracer3.start_span(‘dnac-api-calls’) as span:
C. dnac-tracer3 = init_tracer(‘dnac-tracer3’)
D. with tracer.start_span(‘dnac-api-calls’) as span:
E. tracer = init_tracer(‘dnac-tracer3’)

Selected Answer: AC

Question #: 240
Topic #: 1
Refer to the exhibit. Cisco IOS XE switches are used across the entire network and the description that is filed for all interfaces must be configured. Which code snippet must be placed in the blank in the script to leverage RESTCONF to query all the devices in the device list for the interfaces that are present?

A.
B.
C.
D.

Selected Answer: D