Pass the Cisco Cisco Certified DevNet Associate 200-901 Questions and answers with CertsForce

The Ansible playbook in the exhibit consists of two stages:

Stage 1: Restarts the network service on the eth0 interface.

Stage 2: Starts the httpd service.

Stage 1:

- name: stage1

ansible.builtin.service:

name: network

state: restarted

args: eth0

This stage ensures that the network service on the eth0 interface is restarted.

Stage 2:

- name: stage2

ansible.builtin.service:

name: httpd

state: started

This stage ensures that the httpd service is started if it is not already running.

References:

Ansible Playbook Documentation: Ansible Service Module

The Python script provided is designed to make a POST request to a REST API to create a new task in a to-do list application. Here's a step-by-step explanation of the script:

Import the requests library to handle HTTP requests.

Define the task dictionary with summary and description.

Use the requests.post method to send a POST request to the specified URL, passing the task data as JSON and setting the appropriate Content-Type header.

Check if the response status code is not 201 (which indicates successful creation). If it's not, raise an ApiError with the status code.

Print the created task's ID from the JSON response.

The provided code options are:

requests: the library used for making HTTP requests.

status_code: used to check the HTTP response status.

Content-Type: a header specifying the media type of the resource.

raise: used to raise an exception if the status code is not as expected.

return is not used in this context.

References:

Cisco DevNet Associate Certification Guide

Python Requests Library Documentation

Edge computing processes data locally, close to where it is generated, rather than sending it to a centralized cloud server. This approach enhances privacy control and reduces latency.

Local Processing: Sensitive data is analyzed locally on edge devices, reducing the need to transmit potentially sensitive information over the network.

Privacy Control: By keeping data processing at the edge, organizations can better comply with data privacy regulations and reduce the risk of data breaches.

Reduced Latency: Local data processing minimizes the delay associated with sending data to and from the cloud, improving real-time analysis capabilities.

References:

Edge Computing and Data Privacy: Edge Computing Benefits

The YAML data provided is converted to JSON format. YAML and JSON are both data serialization formats, and the conversion involves retaining the structure and values of the original YAML data. The JSON format uses braces {} and brackets [] to denote objects and arrays, respectively.

Comparing a current version of code to a previous version is a common practice in software development for troubleshooting code failures. This process, often referred to as "diffing," helps developers identify changes that might have introduced bugs or caused the application to behave incorrectly. By pinpointing these changes, developers can more efficiently debug and resolve issues.

References:

Atlassian - Comparing code differences

Cisco DevNet Associate Certification Guide

pyATS (Python Automated Test Systems) is a comprehensive testing framework developed by Cisco, designed specifically for automating the testing of network devices. It provides a robust and flexible environment for creating and running tests on network devices and simulating network automation scenarios.

pyATS enables the creation of reusable test scripts and workflows that can be applied across different network environments and devices.

It supports various protocols and devices, allowing for extensive testing coverage.

It integrates well with other Cisco network automation tools and frameworks, making it a versatile choice for network engineers and developers.

References:

Cisco DevNet pyATS documentation

Cisco DevNet Associate Certification Guide

To minimize the security risk, storing the username and password in a vault is the best practice. A vault, such as HashiCorp Vault or AWS Secrets Manager, securely stores and manages sensitive information, providing encryption and access control. This approach ensures that credentials are not hard-coded or stored in insecure locations, reducing the risk of exposure.

To retrieve a list of hosts using the Cisco DNA Center API, the provided Python script needs to be completed with the appropriate code snippets. Here's how the final script looks:

import json, requests, urllib3

from requests.auth import HTTPBasicAuth

from config import host, username, password

headers = { 'Content-Type': "application/json", 'x-auth-token': "csd0934rjxx" }

def dna_api_auth(host, username, password):

url = "https://{}/dna/system/api/v1/auth/token ".format(host)

response = requests.post(url, auth=HTTPBasicAuth(username, password), headers=headers, verify=False)

token = response.json()["Token"]

return token

def list_dna_devices(token):

url = "https://{}/dna/intent/api/v1/network-device ".format(host)

headers["x-auth-token"] = token

response = requests.get(url, headers=headers, verify=False)

data = response.json()

for item in data['response']:

print(item["hostname"])

token = dna_api_auth(host, username, password)

list_dna_devices(token)

application/json: This is used to set the content type for the headers.

token = response.json()["Token"]: This extracts the authentication token from the response.

data['response']: This accesses the 'response' part of the JSON data returned by the API.

token: This passes the token to the headers for authorization.

json(): This parses the response to JSON format.

for item in data['response']: This loops through each item in the response data.

hostname: This prints the hostname of each device.

References:

Cisco DNA Center Platform: Cisco DNA Center Platform

To enable keepalive for the FastEthernet 2/0 interface using YANG data models and NETCONF in Python, the following steps are required:

Create an Interface Object:

interface = model.Native.Interface.FastEthernet()

This line creates an instance of the FastEthernet interface from the YANG model.

Set the Interface Name:

interface.name = '2/0'

This line sets the name of the interface to 2/0.

Enable Keepalive:

interface.FastEthernet.keepalive_settings.keepalive = True

This line enables the keepalive setting on the FastEthernet interface.

Read the Current Configuration:

interface_data = crud.read(provider, interface)

This line reads the current configuration of the interface from the device.

Update the Configuration:

crud.update(provider, interface)

This line updates the device configuration with the new settings, enabling keepalive on the specified interface.

References:

Cisco YANG Data Models: Cisco YANG Models

YANG Development Kit (YDK): YDK Documentation