200-901 DevNet Associate (DEVASC) Questions and Answers

A containerized application environment meets the requirements of being hardware-independent and allows for the installation and management of the environment to be fully automated. Containers package the application and its dependencies together, ensuring consistency across different environments. This method is also highly compatible with automation tools and orchestrators like Kubernetes, making deployment and management easier and more efficient.

References:

Cisco DevNet Associate Study Guide: Understanding Application Deployment (Chapter 4, Section: Containers and Their Benefits).

The script returns a 401 Unauthorized response, indicating that the request lacks proper authentication. To resolve this, you must include an Authorization header in the HTTP GET request. The value of this header should be the Base64 encoded string of the username and password in the format username:password. This is necessary to authenticate the request and receive a 200 OK response.

References:

Cisco DevNet Associate Study Guide: REST API Authentication Methods (Chapter 7, Section: HTTP Basic Authentication).

Synchronous API requests and asynchronous API requests differ primarily in how and when the client receives a response from the server.

Synchronous API Request: In a synchronous API call, the client sends a request to the server and waits for a response. The client is blocked during this time, meaning it cannot perform other tasks until the server responds. The key characteristic is that the client is able to access the results immediately after the request is processed. This is suitable for operations that need an immediate response and where the processing time is relatively short.

Asynchronous API Request: In an asynchronous API call, the client sends a request and continues its process without waiting for the server to respond. The server processes the request and sends the response back to the client at a later time. The client might receive a task ID (option A), subscribe to a webhook (option B), or poll for status (option D) to check when the operation is complete.

The bash script shown in the exhibit automates the process of downloading, extracting, compiling, installing, and configuring the Cisco DevNet application. It also enables and starts the application automatically.

Download and Extract: The script uses curl to download a tar.gz file and then extracts it using tar -zxf.

Compilation and Installation: The ./configure && make && make install commands compile and install the application.

Enabling and Starting the Service: The systemctl enable devnet and systemctl start devnet commands ensure the application starts automatically on system boot and starts it immediately.

Option B correctly describes the workflow as it includes compilation, installation, configuration, and automatic startup of the application.

The exhibit illustrates a Continuous Integration/Continuous Deployment (CI/CD) pipeline. This method involves continuous integration of code from multiple developers, automated testing, and continuous delivery/deployment to production. It ensures that code changes are automatically built, tested, and deployed, promoting efficient and reliable software development practices.

The docker run command is used to create and start a new container from an image. The -p option maps a port on the host to a port in the container.

Port Mapping: The syntax -p [host_ip:host_port:container_port/protocol] is used to map ports.

Exposing Port 8443: The correct mapping to expose the API on port 8443 and allow external connections is 0.0.0.0:443:8443/tcp, which maps port 443 on the host to port 8443 in the container.

Option B correctly maps the ports and allows external connections.

The platform used to programmatically create a space and invite users for collaboration is Cisco Webex.

A. Cisco Intersight - Incorrect. Cisco Intersight is used for infrastructure management. B. Cisco Finesse - Incorrect. Cisco Finesse is used for contact center management. C. Cisco Webex - Correct. Cisco Webex is used for collaboration and includes APIs to create spaces and invite users. D. Cisco UCM - Incorrect. Cisco Unified Communications Manager (UCM) is used for call processing.

References:

Cisco Webex API Documentation

Cisco Webex Teams API

Refactoring is done during test-driven development (TDD) to improve the maintainability and readability of the code. After writing tests and ensuring that the code passes those tests, developers refactor to clean up the code, making it more efficient and easier to understand without changing its functionality.

A. to enable larger objects and longer methods - Incorrect. Refactoring aims to simplify and streamline code, not make it larger or more complex. B. to improve maintainability and readability - Correct. Refactoring makes the code easier to maintain and understand. C. to ensure that the previous uses of the objects are explained - Incorrect. This is not the purpose of refactoring. D. to ensure the duplication of essential code - Incorrect. Refactoring seeks to reduce code duplication, not ensure it.

References:

Test-Driven Development by Example

The first three pairs of digits in a MAC address, also known as the Organizationally Unique Identifier (OUI), identify the vendor or manufacturer of the network card or adapter. This part of the MAC address is assigned by the IEEE to the manufacturers, ensuring that each MAC address is unique.

To determine the correct JSON snippet for configuring a new interface according to the YANG model, we need to carefully examine both the YANG model definitions and the provided JSON snippets. Here’s a step-by-step explanation:

YANG Model Analysis:

The ietf-interfaces YANG module defines a container interfaces with a list interface.

Each interface has the following important leaves: name, enabled, and description.

The ietf-ip YANG module augments the interface list with a container ipv4, which includes a list address. Each address has the ip and netmask leaves.

Key Elements in JSON:

To configure an interface, the JSON must include the name of the interface, its enabled status, and the IP address configuration.

The structure should reflect the hierarchy defined by the YANG models.

Options Analysis:

Option A:

json

Copy code

"ietf-interfaces:interface": {

"name": "Loopback100",

"enabled": true,

"ietf-ip:ipv4": {

"address": [

{

"ip": "10.255.254.1",

"netmask": "255.255.255.0"

}

]

}

}

This option correctly follows the hierarchy specified in the YANG model. The interface includes name and enabled leaves and augments with ietf-ip:ipv4 which includes the address list with ip and netmask.

Option B:

"ietf-interfaces": {

"interface": {

"name": "Loopback100",

"enabled": true,

"ietf-ip": {

"ipv4": {

"address": [

{

"ip": "10.255.254.1",

"netmask": "255.255.255.0"

}

]

}

}

}

}

This option incorrectly nests interface directly under ietf-interfaces, which does not match the YANG model’s structure.

Option C:

"interface": {

"name": "Loopback100",

"enabled": true,

"ipv4": {

"address": [

{

"ip": "10.255.254.1",

"netmask": "255.255.255.0"

}

]

}

}

This option misses the namespace prefixes ietf-interfaces and ietf-ip required by the YANG model.

Option D:

"ietf-interfaces:interface": {

"name": "Loopback100",

"enabled": true,

"ietf-ip:ipv4:address": [

{

"ip": "10.255.254.1",

"netmask": "255.255.255.0"

}

]

}

This option incorrectly uses ietf-ip:ipv4:address directly, which does not align with the proper hierarchy where address should be nested inside ipv4.

Correct Explanation:

Option A correctly adheres to the YANG model hierarchy and namespace specifications.

It properly nests address within ipv4, which is itself nested within ietf-ip augmentation to interface.

This structure is consistent with how the YANG models define the relationships between the elements.

References:

Understanding of YANG models and their use: Cisco DevNet YANG Introduction

YANG Data Models in NETCONF: RFC 6020

The diff -u command shows the differences between two files. In the output provided:

Lines with + indicate additions.

Lines with - indicate deletions.

From the exhibit:

There are 8 additions (lines marked with +).

There are no deletions.

The original file was 165 lines long. Adding the 8 new lines results in a total of 173 lines.

To ensure the Python code runs successfully, the environment variable WEBEX_TEAMS_ACCESS_TOKEN must be set. This can be done using the export command in a Bash script.

A. define WEBEX_TEAMS_ACCESS_TOKEN=your_access_token_here - Incorrect. define is not a valid Bash command for setting environment variables. B. export WEBEX_TEAMS_ACCESS_TOKEN=your_access_token_here - Correct. This command correctly sets the environment variable for the current session. C. set WEBEX_TEAMS_ACCESS_TOKEN=your_access_token_here - Incorrect. set is not used in this context for setting environment variables in Bash. D. WEBEX_TEAMS_ACCESS_TOKEN=your_access_token_here - Incorrect. This command sets the variable but does not export it to be available to child processes.

References:

Setting Environment Variables in Bash

A MAC address (Media Access Control address) is a unique hardware address assigned to the network interface of a device. It is used for network communication at the data link layer of the OSI model.

A. unique network address that identifies the network interface of a device - Incorrect. This describes an IP address. B. unique network interface address that is provided by the DHCP server - Incorrect. MAC addresses are hardware-based, not provided by DHCP. C. unique hardware address that identifies the network interface of a device - Correct. This is the correct definition of a MAC address. D. unique hardware interface address that is provided by the central switch - Incorrect. MAC addresses are not provided by switches.

References:

Cisco MAC Address Basics

The Python script in the exhibit interacts with Cisco DNA Center APIs to query devices and execute commands. It collects the results of specific show commands from the devices.

Device Query: The script first queries for devices with the platformId of 'C9500-40X'.

Command Execution: It sends commands (show version, show ip int brief) to these devices.

Result Gathering: The script retrieves and processes the results of the executed commands.

Option A accurately describes the process automated by the script, which is to gather the results of the show version and show ip int brief commands.

HTTP status codes in the 2xx range indicate that a request has been received, understood, and processed successfully.

A. 2xx - Correct. This range of status codes indicates successful responses. B. 3xx - Incorrect. This range of status codes indicates redirection messages. C. 4xx - Incorrect. This range of status codes indicates client errors. D. 5xx - Incorrect. This range of status codes indicates server errors.

References:

HTTP Status Codes

The error in the Python code is due to the requests library not being defined, which typically means it hasn't been installed. To resolve this issue, the requests library needs to be installed using the pip install requests command. This will add the necessary module to the Python environment, allowing the code to execute correctly.

The Python script uses nested loops to gather information:

The first loop checks for the "ACME" organization.

If found, it collects information about the networks in that organization.

The second loop checks for the "BLDG21" network.

If found, it gathers information about clients in that network.

This process effectively provides the BLDG21 network information if it is part of the ACME organization.

In the provided Python function enable_function, the parameters are if_name, if_status, and if_type, which correspond to the interface name, status (enabled/disabled), and interface type respectively.

Function Parameters: The function enable_function is designed to take three parameters: the interface name (if_name), the status (if_status), and the type (if_type).

Correct Order and Values: To enable the interface named "Loopback1", you need to pass the correct values in the order they are defined in the function.

Option A correctly calls the function with the interface name "Loopback1", the status true (enabled), and the interface type 'iana-if-type:softwareLoopback'.

The Model-View-Controller (MVC) design pattern provides several advantages, including the ability to present multiple views of the same data to different user groups and the separation of concerns by dividing the application into three interconnected components.

A. to enable multiple views of the same data to be presented to different groups of users - Correct. MVC allows different views to display the same data, enhancing flexibility and usability. B. to provide separation between the view and the model by ensuring that all logic is separated out into the controller - Correct. MVC promotes the separation of concerns, making the application easier to manage and scale. C. to ensure data consistency, which requires that changes to the view are also made to the model - Incorrect. This is not a primary advantage of MVC; changes to the view do not directly affect the model. D. to ensure that only one instance of the data model can be created - Incorrect. This is not a characteristic or advantage of MVC. E. to provide only a single view of the data to ensure consistency - Incorrect. MVC supports multiple views.

References:

MVC Design Pattern

In JSON (JavaScript Object Notation), data structures are represented using arrays and objects. A Python Tuple, which is an ordered and immutable collection of items, is best represented by a JSON array. JSON arrays are ordered lists of values, making them the closest equivalent to Python Tuples.

Object: In JSON, an object is a collection of key/value pairs.

Array: In JSON, an array is an ordered list of values.

Dict: In Python, a dict (dictionary) is a collection of key/value pairs.

Collection: General term for a group of items.

Thus, a Python Tuple would be represented as a JSON array.

The primary security issue in this scenario is that API keys are stored in the configuration files. It is a best practice to store sensitive information such as API keys in a secure vault service rather than in configuration files.

A. Communication between the application and the services is not encrypted - Incorrect. The communication is through HTTPS, which is encrypted. B. The database credentials should be stored in the configuration files so that they are secured on the same server - Incorrect. Database credentials should be securely obtained, as mentioned, through a vault service. C. The API keys are stored in the configuration files but should be stored in the vault service - Correct. Storing API keys in configuration files poses a security risk. They should be stored in a secure vault service. D. The synchronization logs should be encrypted and not stored in a relational database - Incorrect. The issue is not about storing logs in a relational database, but rather the storage of API keys in configuration files.

References:

Secure Secrets Management

Best Practices for Storing API Keys

Agentless configuration management systems, such as Ansible, do not require agents to be installed on the managed hosts. Instead, they leverage existing protocols and services to perform configuration tasks.

Agentless Approach: These systems rely on protocols like SSH (for Unix/Linux) or WinRM (for Windows) to communicate with and manage the hosts.

No Agent Installation: Managed hosts do not need any additional software (agents) installed, which simplifies management and reduces overhead.

Interpreters: They may require the managed hosts to have an interpreter for scripts (e.g., Python) but primarily use existing network protocols for communication.

Option D correctly identifies that agentless configuration management systems use existing protocols to interface with managed hosts.

In this question, the network engineer is using the RESTCONF API to update information about device interfaces. The RESTCONF API uses the YANG data modeling language and can encode data in either XML or JSON format. The appropriate headers must be set to specify the content type and the format in which the data is expected.

RESTCONF API: This API allows network devices to be managed using web-based protocols, and it relies on the YANG data model to represent the configuration data.

Content-Type and Accept headers: These headers define the media type of the resource. The Content-Type header tells the server what type of data is being sent by the client. The Accept header indicates the type of data that the client can receive from the server.

Option A is the correct answer because it specifies the correct content type and accept headers for using XML with YANG data models in RESTCONF API calls.

To create and switch to a new branch called "my-bug-fix" in Git, you use the git checkout -b command. This command creates the branch and switches to it in one step.

A. git checkout -b my-bug-fix - Correct. This command creates a new branch and switches to it. B. git branch -b my-bug-fix - Incorrect. The -b option is not valid with git branch. C. git branch my-bug-fix - This creates a new branch but does not switch to it. D. git checkout my-bug-fix - This switches to an existing branch but does not create a new one.

References:

Git Branching - Creating a Branch

A developer is creating a script to interact with a REST API service that requires basic authentication. The correct combination of payload and headers using Basic Authentication with the provided Base64 encoded credentials is:

A. This option does not use headers correctly. B. Option B - Correct. This option correctly places the 'Authorization' header in the headers dictionary with 'Basic' authentication. C. This option uses 'Bearer' instead of 'Basic' for the 'Authorization' header. D. This option uses 'Bearer' instead of 'Basic' for the 'Authorization' header.

References:

HTTP Authentication

Base64 Encoding

The main purpose of a code review is to identify and review errors, ensuring code quality and adherence to coding standards. It involves evaluating the code for bugs, security vulnerabilities, and performance issues, and discussing potential improvements with the team. This collaborative process helps catch errors early, fosters knowledge sharing, and improves the overall quality of the codebase.

References:

Cisco DevNet Associate Study Guide: Code Review Best Practices (Chapter 6, Section: Importance of Code Reviews).

A routing table on a network device serves as a map for determining the best path to route packets to their destinations. It lists all the routes to particular destinations, including both the next-hop addresses and the associated metrics. The routing table also includes static entries (manually configured routes) and dynamic entries (routes learned through routing protocols).

References:

Cisco DevNet Associate Study Guide: Understanding Routing Tables (Chapter 4, Section: Routing and Switching Fundamentals).

In version control systems, code review is typically performed before the code is merged into the main branch. The code review process involves evaluating the changes, ensuring they meet the project's coding standards, and identifying potential issues. This process helps maintain code quality and integrity before integration into the larger codebase.

References:

Cisco DevNet Associate Study Guide: Version Control and Code Review (Chapter 6, Section: Best Practices for Version Control).

In the provided sequence diagram, each call must complete before the next one can proceed, indicating that the calls are synchronous. Synchronous calls block further execution until the response is received, maintaining a sequential order of operations.

Synchronous Nature: The diagram shows each function call being made and then waiting for a callback before proceeding to the next step.

Blocking Behavior: Each interaction completes fully before the next one starts, which is characteristic of synchronous operations.

Option C correctly identifies that all the calls shown in the sequence diagram are synchronous.

Cisco Umbrella provides DNS-layer security and can block all traffic to a domain using a single API call. This feature is particularly useful for preventing access to malicious sites and enhancing security across the network by controlling domain access.

References:

Cisco DevNet Associate Study Guide: Security with Cisco Umbrella (Chapter 8, Section: DNS-Layer Security and API Integration).

In the test-driven development (TDD) model, after a test fails, the next step is to change the code to make the test pass. TDD involves writing a test for a new feature or functionality, running the test to see it fail, then writing the minimal amount of code necessary to pass the test, and finally refactoring the code to meet quality standards.

Model-driven programmability offers several benefits:

Model-driven APIs for abstraction and simplification: These APIs provide a higher level of abstraction, making it easier to manage and automate networks.

Models decoupled from transport, protocol, and encoding: This decoupling ensures that the same model can be used with different transport protocols, making the system more flexible and easier to integrate with various technologies.

Webhooks are user-defined HTTP callbacks triggered by specific events. They are effective in scenarios where an automated response to an event is required. For example, informing a chat channel after a deployment event or sending an email after a transaction are practical uses of webhooks. These use cases leverage the real-time capabilities of webhooks to automate responses and notifications based on events.

References:

Cisco DevNet Associate Study Guide: Event-Driven Automation (Chapter 8, Section: Webhooks and Their Use Cases).

In the provided cURL command, the developer needs to include an authorization header with the access token to authenticate the API request. Without proper authentication, the server will reject the request and return an error code.

To complete the get_auth_token() function in the script to obtain a valid authentication token using HTTP Basic Authentication, you need to use the requests library correctly. The correct approach involves using the requests.post() method with the HTTPBasicAuth function.

A. resp = requests.post(url, auth=HTTPBasicAuth(DNAC_USER, DNAC_PASSWORD)) token = resp.json()['Token'] return token

Correct. This option uses requests.post() and HTTPBasicAuth properly. It retrieves the token from the JSON response.

B. resp = requests.post(url, auth=(DNAC_USER, DNAC_PASSWORD)) token = resp.json()['Token'] return token

Incorrect. This option incorrectly passes the auth credentials as a tuple without HTTPBasicAuth.

C. resp = http.post(url, auth=HTTPBasicAuth(DNAC_USER, DNAC_PASSWORD)) token = resp.json()['Token'] return token

Incorrect. http is not a valid method from the requests library.

D. resp = http.post(url, auth=(DNAC_USER, DNAC_PASSWORD)) token = resp.json()['Token'] return token

Incorrect. This option uses http.post(), which is incorrect.

References:

requests - HTTP for Humans

Cisco DNA Center Platform

The exhibit shows an example of cross-site scripting (XSS), a security vulnerability where an attacker injects malicious scripts into content from otherwise trusted websites. In this case, the alert function is used to demonstrate the potential for XSS attacks, where user input is improperly sanitized, allowing script execution.

The docker build command is used to build an image from a Dockerfile. The -t option tags the image with a specified name and tag.

Tagging: The docker tag command associates an image ID with a repository and tag.

Building with Tag: The correct command to build the Docker image and tag it as local/app:0.4 is docker build -t local/app:0.4.

Option D is the correct command to build and tag the image.

The error code 401 indicates an unauthorized request, which can often result from using an incorrect API endpoint. To solve this problem, ensure that the API URL correctly matches the endpoint for retrieving the device list. This URL must point to the correct API endpoint as specified by the Cisco DNA Center API documentation.

References:

Cisco DevNet Associate Study Guide: Interacting with Cisco DNA Center APIs (Chapter 7, Section: Using API Endpoints and Proper Authentication).

Private IP addresses are used within private networks and are not unique globally. They can be reused in different private networks without conflict.

Non-unique Addresses: Private IP addresses do not have to be unique globally, allowing them to be reused in different networks.

Repetition in Local Networks: They can be repeated within different local networks as they are not routable on the public Internet.

Options C and D correctly describe properties of private IP addresses.

Ansible is a configuration management tool that has agentless capabilities. It uses SSH for communication and does not require any agent software to be installed on the managed nodes. This simplifies management and reduces overhead.

The sequence diagram shows the process where the API client first calls the /organizations endpoint to get the list of organization IDs. Then, for each organization, it makes a call to the /organizations/(orgId)/networks endpoint to retrieve the networks for that organization. Since there are two organizations, the GetAllNetworks function will make two parallel calls to the /organizations/(orgId)/networks endpoint, one for each organization.

References:

Cisco DevNet Associate Study Guide: Using Cisco Meraki APIs (Chapter 7, Section: Understanding Meraki API Calls and Endpoints).

The Python script shown in the exhibit collects CLI arguments, organizes data according to the Cisco-IOS-XE-native YANG model, and utilizes Cisco REST APIs to make configuration changes. The workflow being automated by the script is adding a new route to a device.

A. updating an existing route on the device - Incorrect. The script is adding a new route, not updating an existing one. B. adding a new route to a device - Correct. The script adds a new route using the provided prefix, mask, and IP address. C. including a route on the device and overwriting the current routes - Incorrect. The script does not indicate it overwrites existing routes. D. deleting the route that is passed through the command-line variables - Incorrect. The script is adding a route, not deleting one.

References:

Cisco IOS XE YANG Data Models

Cisco REST API Documentation

The provided documentation outlines how to use Basic HTTP Authentication with the Cisco AMP API. The correct method involves encoding the client ID and API key in base64 format and then including them in the authorization header. However, in the given scripts, the use of the requests library’s auth parameter directly with the client ID and API key is also a valid method.

Option A correctly uses the requests library to make an API call with the client ID and API key. This method is supported and valid as per the documentation.

python

Copy code

import requests

amp_client_id = 'alb2c3d4e5f6g7h8i9j0'

amp_login_password = 'l0g1n_p@ssw0rd'

url = 'https://api.amp.cisco.com/v1/version '

request = requests.get(url,

auth=(amp_client_id, amp_login_password))

print(request.json())

Client ID and API Key: amp_client_id and amp_login_password are set with the values provided.

URL: The URL for the AMP API endpoint is correctly set.

GET Request: The requests.get method is used with the auth parameter that takes a tuple of the client ID and API key.

Response: The response is printed in JSON format.

Option B:

Does not use the auth parameter or a header for Basic Authentication, thus it will fail.

Option C:

Uses a single amp_auth_token which does not follow the provided documentation method.

Option D:

Incorrectly uses the auth parameter with a concatenated client ID and API key without specifying Basic Authentication in the header.

References:

Cisco AMP for Endpoints API Documentation

Requests: Authentication

An HTTP 502 Bad Gateway error indicates that the server acting as a gateway or proxy received an invalid response from the upstream server. This suggests there may be an issue with the configuration or availability of the server behind the load balancer.

HTTP 502 Error: This error occurs when the load balancer or gateway receives an invalid response from the backend server.

Server Configuration: The issue is likely due to misconfiguration or problems with the backend server that needs to be resolved.

Option A is correct as it identifies that the issue lies with the server configuration behind the load balancer.

RPC (Remote Procedure Call) APIs and REST (Representational State Transfer) APIs have different approaches to communication and authentication.

RPC APIs: Authentication can be more complex and is often embedded within the service calls themselves, sometimes requiring specific provisions for the caller and the service.

REST APIs: Authentication typically relies on standardized methods such as HTTP headers, including Basic Auth, OAuth tokens, or API keys, making it more straightforward and standardized across different services.

References:

Cisco DevNet Documentation - APIs

Cisco DevNet Associate Certification Guide

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

Rate limiting, as explained previously, is essential to ensure that an application can handle traffic spikes without crashing. By limiting the rate at which requests are processed, the application can maintain stability and reliability under varying load conditions.

Traffic Spike Management: Rate limiting helps manage unexpected surges in traffic by capping the number of allowable requests within a specified period.

Reliability Maintenance: By preventing overloading, rate limiting ensures that the application remains operational and responsive, maintaining its reliability.

References:

Managing Traffic Spikes with Rate Limiting: Rate Limiting Strategies

The YANG model provided in the exhibit defines the structure for interface information, including fields for name, admin-status, if-index, and statistics. The correct XML snippet must match this structure and use the appropriate namespaces and field names as defined in the YANG model.

Namespace: The XML must include the namespace urn:ietf:params:xml:ns:yang:ietf-interfaces and the prefix if.

Interface Information: The XML must include elements for name, admin-status, if-index, and statistics as defined in the YANG model.

Field Names and Values: The field names must match the YANG model (admin-status, if-index, in-octets, in-unicast-pkts).

Option D is the correct XML snippet because it accurately conforms to the YANG model. It includes the required elements and correctly uses the namespace and field names:

GigabitEthernet1

1

1

408164820

728061

To address security concerns about sensitive information such as usernames and passwords in the application code, the best approach is to utilize environment variables. This is a common and recommended practice to enhance security because:

Environment Variables: Storing sensitive information in environment variables helps prevent exposure of these details in the codebase. They can be easily managed and changed without modifying the code.

Separation of Configuration from Code: This approach follows the principle of separating configuration from code, making the application more secure and easier to manage.

Security Best Practices: Using environment variables aligns with security best practices for managing secrets, which include not hard-coding sensitive data and keeping them outside the source code repository.

Hence, using environment variables for storing sensitive details like usernames and passwords (Answer B) is the appropriate and secure solution.

To set an environmental variable in a Linux system using Bash, the export command is used. This command sets the environment variable for the current session, and any subsequent commands or processes will inherit this environment variable.

For example, to set an environment variable named "website" with the value "cisco.com", you use the following command:

export website="cisco.com"

This sets the variable website and makes it available to any subprocesses started from the shell.

References:

GNU Bash Reference Manual - Bash Builtin Commands

Cisco DevNet Associate Certification Guide

To provide an encrypted connection when using API keys to communicate with a REST API, the connection must use HTTPS. The curl command with the -X GET option and an HTTPS URL ensures that the communication is encrypted, protecting the API key and data in transit.

The HTTP status code 204 means that the server has successfully processed the request, but there is no content to send in the response. This status code is typically used when the server fulfills the request, but no further information is needed to be returned to the client. The 204 status is used to indicate that the request was successful and that the client should not refresh or change the current page view. For example, this might be used when a form submission is processed without requiring any update to the client.

References:

MDN Web Docs - HTTP 204 No Content

Cisco DevNet Associate Certification Guide

The Python script shown in the exhibit is designed to interact with Cisco DNA Center APIs. Here's a step-by-step breakdown of what the script does:

It imports necessary libraries and sets the BASE_URL, AUTH_URL, and TOKEN for authentication.

It defines the headers to include the authentication token and content type.

It constructs URLs for fetching the device count, all devices, and devices by ID.

The devices_func function makes a GET request to fetch the total count of devices.

The devices_test function fetches a list of network devices based on query parameters.

The devices_info function retrieves detailed information about a specific device using its ID.

The script then prints the total count of devices, all devices, and filtered device information based on the hostname and platform ID.

In the final step, after executing the script, it fetches devices with the hostname "CSR1Kv-01.devnet.local" and then filters the list by platform ID "C9500-40X". This results in displaying the filtered information about the device that matches both the hostname and platform ID criteria.

References:

Cisco DevNet Associate Certification Guide

Cisco DNA Center API Documentation

Cross-Site Request Forgery (CSRF) is a type of attack that forges a malicious HTTP request and sends it from a user's browser to a different site where the user is authenticated. The attacker tricks the user into executing unwanted actions on a web application in which the user is currently authenticated. This can lead to unauthorized actions being performed on the user's behalf.

References:

Cisco DevNet Associate Certification Guide

OWASP CSRF Prevention Cheat Sheet

Continuous Integration (CI) is a DevOps practice where developers frequently merge their code changes into a central repository. This practice aims to detect integration bugs as quickly as possible and improve the quality of the software. CI involves running automated tests and builds, ensuring that new code changes do not break the existing functionality. In the given scenario, the group of developers wants to deliver release-ready code and run automated tests frequently, which aligns with the principles of Continuous Integration.

References:

Atlassian - What is Continuous Integration?

Cisco DevNet Associate Certification Guide

The bash script in the exhibit performs the following actions step-by-step:

#!/bin/bash - This is the shebang line that tells the system this script should be run with the bash shell.

apt-get update - This command updates the package lists for upgrades for packages that need upgrading, as well as new packages that have just come to the repositories.

apt-get -y install git - This command installs git automatically confirming the installation with -y.

cd Code/Network_Config - This command changes the directory to Code/Network_Config.

mkdir PRODUCTION - This command creates a new directory named PRODUCTION.

cd PRODUCTION - This command changes the directory to the newly created PRODUCTION directory.

touch state.yml - This command creates an empty file named state.yml.

vi state.yml - This command opens the state.yml file in the vi editor.

Therefore, based on the above script analysis:

A directory called PRODUCTION is created (Answ

XML (eXtensible Markup Language) uses tags to define the structure and content of the data. Each element is enclosed in tags, which makes the data self-descriptive and facilitates the hierarchical organization of information. This is a key feature that distinguishes XML from other data formats.

Network Address Translation (NAT) on the firewall is responsible for translating the public IP address to the private IP addresses of internal servers. If traffic is being forwarded to the wrong server, it indicates a misconfiguration in the NAT rules.

NAT Configuration: NAT rules need to be correctly configured to forward traffic to the appropriate internal server based on the destination IP and port.

Misconfiguration: If NAT rules are incorrect, traffic may be directed to the wrong internal IP address, as seen in the exhibit where traffic is sent to server 1 instead of server 2.

Option D is correct as the issue is caused by NAT misconfiguration on the firewall.

The provided Python script interacts with an ACI (Application Centric Infrastructure) environment. It logs into the ACI fabric and collects information about groups. Specifically, the getstuff function uses an API call to retrieve data from the ACI and processes it to extract group information.

An ICMP "time exceeded in-transit" message indicates that the TTL (Time to Live) of a packet has expired. The TTL value is a counter that decreases by one each time the packet passes through a router. When the TTL reaches zero, the packet is discarded, and an ICMP "time exceeded" message is sent back to the sender. This typically happens when the packet takes too many hops or the destination is too far away, causing the TTL to expire before reaching the destination.

For a web-based application that captures and processes credit card information, it is essential to ensure the security of the private customer data. Enabling the encryption of network traffic, typically through TLS (Transport Layer Security), protects sensitive information by encrypting data transmitted between the client and server. This prevents unauthorized access and ensures data integrity and confidentiality during the transaction process.

To parse XML data in Python, a developer typically imports a library that provides the necessary functions and methods for XML parsing.

Libraries for XML Parsing: Python has several libraries for parsing XML, such as xml.etree.ElementTree, lxml, and minidom.

Functionality: These libraries offer functions and methods to read, manipulate, and extract data from XML files.

Example:

import xml.etree.ElementTree as ET

tree = ET.parse('file.xml')

root = tree.getroot()

References:

Python XML Parsing: Python XML Documentat

Refer to the exhibit which shows a sequence diagram illustrating a client-server interaction. The correct sequence of steps that match the code snippet is as follows:

Step 1: POST /events - The client posts an event to the server.

Step 2: GET /messages/<messageId> - The client retrieves the message details from the server using the message ID.

Step 3: Response /messages/<messageId> - The server responds with the message details.

Step 4: GET /team-memberships?teamId=<teamId> - The client retrieves team membership details using the team ID.

Step 5: POST /message - The client posts a message.

Step 6: Response /message - The server responds with the message confirmation.

The correct code snippet represents the sequence diagram correctly:

@flask_app.route('/events', methods=['POST'])

def webex_teams_webhook_events():

json_data = request.json['data']

response = requests.get(MESSAGE_URL + json_data['id'], headers=headers)

if response.json()['text'] == 'Alert':

response = requests.get(TEAM_MEMBERSHIPS_URL, headers=headers, params=params)

for info in response.json()['items']:

data = {'personId': info['personId'], 'text': 'Alert'}

REST APIs are designed around resources that are identified by URLs. Operations are performed on these resources using standard HTTP methods like GET, POST, PUT, and DELETE. In contrast, RPC (Remote Procedure Call) APIs are designed around actions or operations, where the focus is on invoking methods or functions rather than manipulating resources.

Latency refers to the delay between a client request and a server response. A large distance between a client device and a host server increases the latency due to the time it takes for data to travel over the network.

Latency: The time delay experienced in a system, particularly in networking, where it refers to the time taken for data to travel from the source to the destination.

Impact: High latency can result in slow response times, negatively impacting the performance of applications, especially those requiring real-time interactions.

References:

Network Latency Overview: Network Latency

Cisco Intersight is a cloud-based management platform that provides comprehensive management for Cisco UCS and HyperFlex systems. It integrates with Cisco UCS Director and UCS Manager to control server, network, storage, and virtual resources, supporting policy-driven management for up to 10,000 physical Cisco servers. Intersight offers advanced capabilities such as proactive support and a robust API for automation and integration, ensuring seamless operations across various infrastructures.

Rate limiting is a technique to control the rate of incoming and outgoing traffic to or from a network. If rate limiting is not implemented, excessive API requests can overwhelm the server, causing long response times and abandoned requests.

Abandoned Requests: When a server is overwhelmed with too many requests, it may not process them all, leading to abandoned requests.

Long Response Times: Without rate limiting, the server might be handling more requests than it can efficiently process, resulting in delayed responses.

Solution: Implementing rate limiting ensures that the server processes requests at a manageable rate, improving performance and reliability.

References:

Rate Limiting and API Performance: Understanding Rate Limiting

DNS (Domain Name System) is the technology responsible for resolving a host name to an IP address. It translates domain names, which are easier for humans to remember, into IP addresses that are used by network devices to locate and communicate with each other over the internet. When a user types a domain name into a web browser, the DNS server maps it to the corresponding IP address so the browser can load the desired web page.

The principle that best describes the DevOps practice outlined in the question is "end-to-end responsibility". In DevOps, teams are responsible for the entire lifecycle of the application, including development, deployment, continuous integration/continuous delivery (CI/CD), monitoring, and performance improvements. This holistic approach ensures that the same team manages all aspects of the application's lifecycle, leading to better collaboration, faster deployment cycles, and improved overall quality and reliability of the software.

References:

Cisco DevNet Associate Certification Guide

DevOps Handbook: How to Create World-Class Agility, Reliability, & Security in Technology Organizations

When configuring a Cisco IOS XE networking device using RESTCONF, the default data encoding method is application/yang-data+json. This MIME type indicates that the data is encoded in JSON format and structured according to YANG data models. YANG (Yet Another Next Generation) is a data modeling language used to model configuration and state data manipulated by the NETCONF protocol, which RESTCONF leverages.

References:

Cisco DevNet Documentation - RESTCONF

Cisco DevNet Associate Certification Guide

Infrastructure as Code (IaC) principles emphasize the use of code to manage and provision computing infrastructure. The key situations that align with IaC principles include:

Easily reproducible systems: Infrastructure can be recreated consistently across different environments using code, ensuring that systems are reliable and predictable.

Repeatable processes: Using scripts and configuration files to automate infrastructure setup and management ensures that processes can be repeated accurately and efficiently.

References:

Infrastructure as Code (IaC) Principles

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.

In YANG, a "container" is a grouping of related nodes and sub-nodes. The "interfaces" object in the YANG model is a container for interface-related data.

Container: The container statement is used to define an interior data node in the YANG data tree.

Structure: The exhibit shows that "interfaces" encapsulates other nodes such as interface, name, description, etc., indicating that it is a container.

References:

YANG Data Modeling Language: YANG RFC

Ansible playbooks are used to define the desired state of a device configuration. Playbooks contain a series of tasks that describe the configuration management, deployment, and orchestration tasks. They are written in YAML and are designed to be simple yet powerful, allowing users to define the state and ensure that devices are configured accordingly.

The provided RESTCONF query is configuring network interfaces using the YANG data model. Based on the JSON data:

GigabitEthernet1: This interface has an enabled status set to true and an IP address configured.

GigabitEthernet2: This interface has an enabled status set to false, which means it is being shut down.

GigabitEthernet3: This interface is also set with an enabled status of false.

The descriptions for these interfaces are also included in the configuration, so the descriptions for two interfaces (GigabitEthernet1 and GigabitEthernet2) are applied.

References:

RESTCONF and YANG Model Basics

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

synchronous: Code execution must wait for an API call to return before continuing.

asynchronous: Code execution does not need to wait for an API call to return before continuing.

REST: Data is called indirectly using generic HTTP methods such as GET, POST, PUT, and DELETE.

RPC: Calls to request a service from a remote server must execute the same way as a request to the local system.

Comprehensive Detailed Step by Step Explanation with References

Synchronous:

Explanation: In a synchronous API call, the client must wait for the server to process the request and return a response before it can proceed with further execution.

Mapping: "Code execution must wait for an API call to return before continuing."

Asynchronous:

Explanation: In an asynchronous API call, the client can continue processing other tasks while waiting for the server to respond. This improves the efficiency and responsiveness of the application.

Mapping: "Code execution does not need to wait for an API call to return before continuing."

REST (Representational State Transfer):

Explanation: REST is an architectural style for designing networked applications. It relies on a stateless, client-server communication protocol, typically HTTP. RESTful APIs use standard HTTP methods (GET, POST, PUT, DELETE) to perform operations on resources.

Mapping: "Data is called indirectly using generic HTTP methods such as GET, POST, PUT, and DELETE."

RPC (Remote Procedure Call):

Explanation: RPC is a protocol that one program can use to request a service from a program located on another computer in a network. The calls are made in the same way as a local function call.

Mapping: "Calls to request a service from a remote server must execute the same way as a request to the local system."

References:

Cisco DevNet Associate Certification Guide, Sections on API styles and their characteristics

Official Cisco documentation on RESTful and RPC APIs

General programming resources on synchronous vs. asynchronous API calls

Therefore, the correct mapping is:

synchronous → "Code execution must wait for an API call to return before continuing."

asynchronous → "Code execution does not need to wait for an API call to return before continuing."

REST → "Data is called indirectly using generic HTTP methods such as GET, POST, PUT, and DELETE."

RPC → "Calls to request a service from a remote server must execute the same way as a request to the local system."

Model-driven programmability refers to the use of a consistent data model to manage and automate network devices. Key capabilities include:

Single Data Model Across the Network: Ensures uniformity and consistency in how data is represented and managed across different network devices and platforms.

Automation and Scalability: Facilitates automated network configurations and operations, enabling scalability.

Interoperability: Using standardized models (like YANG) allows for interoperability between different network devices and management tools.

Abstracted API Interfaces: Provides abstracted and consistent APIs that can be used across multiple devices, reducing the complexity of network automation scripts.

References:

Cisco Model-Driven Programmability

The command git branch -D test forcefully deletes the local branch named test, even if it has unmerged changes.

Deleting Branches: git branch -D is used to delete a branch forcefully.

Force Deletion: The -D flag forcefully deletes the branch regardless of its merge status.

Option C correctly describes the action of the command, which is to delete the test branch.

Cisco Modeling Labs (CML) is a network simulation tool that allows users to create, configure, and simulate networks with Cisco devices and topologies.

Cisco Modeling Labs (CML): CML provides a virtual environment where users can simulate network topologies and devices, including routers, switches, and other network components.

Simulation and Testing: CML allows users to test configurations, troubleshoot network issues, and study network behavior in a controlled environment.

References:

Cisco Modeling Labs: Cisco Modeling Labs

Cisco DevNet Sandbox provides developers with access to a variety of Cisco technologies in a lab environment. It is an essential resource for developers who want to test and build applications using Cisco APIs and products.

DevNet Sandbox: This platform offers pre-configured, ready-to-use environments that allow developers to experiment with Cisco products, including security products, without the need to set up and configure their own infrastructure.

References:

Cisco DevNet Sandbox

In the given network topology, the communication from Server 1 and Server 2 goes up to device D. Both servers are connected to Device E, which is a Layer 2 switch. Device E is connected to Device D, which serves as the next hop for routing the packets to other parts of the network, including the internet through Device C.

The PUT method is used to create or update a resource at a specific URL. In the given RESTCONF request and response example, the response indicates a successful creation of a resource, as evidenced by the HTTP status code 201 (Created). The request to create the "Australian Cattle Dog" resource under the "dogbreed" category would use the PUT method to ensure the resource is created or updated at the specified location.

References:

Cisco DevNet Documentation - RESTCONF Operations

IETF RFC 8040 - RESTCONF Protocol

In REST architecture, the stateless constraint indicates that no client context should be stored on the server between requests. Each request from the client to the server must contain all the information needed to understand and process the request.

Stateless: Ensures that each request is independent and contains all necessary information.

Uniform interface: Defines a standard way of interacting with resources.

Cacheable: Responses must define whether they are cacheable to improve performance.

Client-server: Separates the client and server roles.

Check below the answer exact.

The cURL command is used to make HTTP requests from the command line. To retrieve a resource in JSON format using OAuth, the command must include the following:

Authorization header: Use the -H option to include the OAuth access token for authentication.

Accept header: Specify that the response should be in JSON format by using the -H option with Accept: application/json.

URL: Provide the URL of the API endpoint.

This command retrieves the specified resource from the API, using the provided OAuth token to authenticate the request and requesting the response in JSON format.

Solution as below

To request a service ticket using the APIC-EM REST API, the following Python script can be used:

Import necessary libraries (requests and json).

Define the APIC-EM controller's URL.

Create the payload with the username and password.

Set the header to specify the content type as JSON.

Make a POST request to the /api/v1/ticket endpoint with the payload and header.

Parse the JSON response to extract the service ticket.

References:

Cisco DevNet Associate Exam Topics: APIs and Automation (understanding how to use REST APIs)

APIC-EM API Documentation (provides details on endpoints and request structures)

1 – B, 2 – E, 3 – C, 4 – D, 5 – A

In the context of webhooks, an application that interacts with a webhook can be described as a Listener or Receiver:

Listener: The application waits for incoming HTTP POST requests sent by the webhook.

Receiver: The application receives the data payloads from the webhook when certain events occur.

Solution below

To list the networks in a Meraki organization using the Meraki API, you need to construct a proper cURL command. The command must include the URL endpoint specific to the Meraki organization ID and the required API key for authentication. The correct cURL command to list networks in the organization with ID 384279060 is:

curl -X GET -L \

--url https://api.meraki.com/api/v0/organizations/384279060/networks \

-H 'X-Cisco-Meraki-API-Key: $meraki_api_key'

Here:

-X GET: Specifies the request method as GET.

-L: Follows any redirects.

--url: Specifies the API endpoint URL.

-H 'X-Cisco-Meraki-API-Key: $meraki_api_key': Adds the API key header for authentication.

References: Cisco DevNet Associate Certification Guide, Chapter on Cisco Meraki APIs and REST API calls.

The exhibit demonstrates an example of cross-site scripting (XSS). This type of attack involves injecting malicious scripts into web pages viewed by other users. In this example, the script is embedded into a URL, and when accessed, it displays an alert message in the web browser.

Cross-Site Scripting (XSS): A security vulnerability typically found in web applications that allows attackers to inject malicious scripts into content from otherwise trusted websites.

References: Cisco DevNet Associate Certification Guide, Chapter on Security, and OWASP documentation on Cross-Site Scripting.

A – E, B – D, C – B, D – C, E – A, F – F

The YANG module shown in the exhibit is for interface management. It augments the ietf-interfaces module and defines parameters specific to Ethernet interfaces, such as auto-negotiation, duplex mode, and speed. This module is designed to manage the configuration and operational state of Ethernet interfaces. References for YANG modules can be found in the IETF YANG Data Model for Interface Management.

Statement B: One of the routers has two connected serial interfaces.

This statement is true if the diagram indicates that a router has two serial interfaces. In network diagrams, routers often have multiple interfaces to connect different segments or other routers, particularly for WAN connections.

Statement E: The subnet address of PC-B has 18 bits dedicated to the network portion.

If PC-B's subnet is represented by an address such as 192.168.x.x/18, then 18 bits are used for the network portion, leaving 14 bits for host addresses. This aligns with standard subnetting practices where a /18 subnet mask means the first 18 bits define the network, and the remaining bits define host addresses.

For example, a subnet mask of 255.255.192.0 corresponds to /18 in CIDR notation, indicating that the first 18 bits are for the network portion.

Incorrect Statements:

Statement A: PC-A and PC-B are in the same subnet.

This statement can be evaluated based on the IP addresses and subnet masks provided for PC-A and PC-B. If they share the same network portion of their addresses and subnet masks, then they are in the same subnet. However, without explicit addresses, this cannot be verified.

Statement C: The subnet of PC-C can contain 256 hosts.

For a subnet to contain 256 hosts, it would need a /24 subnet mask (255.255.255.0), which provides 256 IP addresses (254 usable for hosts). The subnet mask should be examined to determine the validity of this statement.

Statement D: R1 and R3 are in the same subnet.

This depends on the IP addresses and subnet masks assigned to the interfaces on R1 and R3. If they are within the same network range, then they would be in the same subnet.

Since the network diagram is not provided, the verification is based on common networking principles and standard practices in subnetting. For detailed and accurate confirmation, the exact IP addresses, subnet masks, and interface connections need to be reviewed.

To ensure the result set is returned in reverse chronological order based on when messages were entered, we need to use the sortBy parameter with the value lastactivity. This parameter sorts the rooms by their last activity timestamp, ensuring the most recent rooms are listed first.

Example:

GET /v1/rooms?sortBy=lastactivity

References:

Cisco Webex Teams API Documentation (explains query parameters and their usage in API calls)

Cisco DevNet Associate Exam Topics: APIs and Automation (understanding how to utilize query parameters to retrieve data)

Test-Driven Development (TDD) is a software development approach where tests are written before the actual code. The process follows these steps:

Write a test before writing code (B): Developers write tests for a new function or feature before implementing it. This ensures that the tests define what the code is supposed to do.

Enable code refactoring (A): Because tests are written first, TDD supports continuous refactoring of the code. Developers can confidently improve and clean up code, knowing that existing functionality is verified by the tests.

1 – D, 2 – F, 3 – A, 4 – E, 5 – B, 6 – G, 7 - C

1 – D, 2 – A, 3 – H, 4 – F, 5 – G, 6 – E, 7 – C, 8 – B

The issue shown in the sequence diagram is an HTTP 401 Unauthorized response. This suggests that the authentication credentials provided are incorrect or improperly formatted. The correct format for the credentials in a cURL command should be without quotes around the username and password. Hence, changing -u 'cisco

' to -u cisco

resolves the issue.

A version control system offers several advantages:

Branching and Merging: Developers can work on features, bug fixes, or experiments in isolation (branches) without affecting the main codebase. Once the work is completed, it can be merged back into the main branch, facilitating organized and controlled development workflows.

The function my_func() returns True when it executes normally. To test this function using Python's unittest framework, the correct assertion to use is assertTrue. This method tests if the given expression evaluates to True.

Option A (self.assertTrue(my_func())): This assertion checks if my_func() returns True.

Option B (self.assertRaises(my_func())): This is used to check if a specific exception is raised, which is not applicable here.

Option C (self.assertEqual(my_func(), 'true')): This checks if my_func() returns the string 'true', which is not correct as my_func() returns a boolean True.

Option D (self.assertFalse(my_func())): This checks if my_func() returns False, which is the opposite of what is needed.

1 – B, 2 – E, 3 - F

Routing protocol traffic is handled on the control plane of a network device. The control plane is responsible for the exchange of routing information, the computation of the best paths, and the creation of the routing table. Protocols such as OSPF, BGP, and EIGRP operate at the control plane level to ensure that routers have the necessary information to make forwarding decisions. The data plane, on the other hand, is responsible for the actual forwarding of packets based on the routing table created by the control plane. More information on network planes can be found in the Cisco Networking Basics.

Generating log bundles is a resource-intensive task that can cause high CPU utilization on the Cisco DNA Center. When the CPU spikes, it can affect the performance of other critical tasks, such as forwarding voice IP packets, leading to delays and poor voice quality. This is especially noticeable during business hours when network utilization is high, and voice traffic is sensitive to latency and jitter. More details can be found in Cisco DNA Center documentation on Managing Logs and System Performance.

Version control software offers numerous benefits to development teams. Key advantages include:

Comparisons between revisions of source code files: Version control allows developers to compare different versions of source code files, track changes, and identify what modifications were made and by whom. This is essential for debugging and maintaining code quality.

Access to current code and history for new team members: New team members can quickly get up to speed by accessing the current version of the code and the entire history of changes. This transparency facilitates onboarding and improves collaboration among team members.

Cisco Intersight API interactions can be encoded in XML or JSON and require an API key in the HTTP header for authentication: This statement is true. Cisco Intersight APIs support both XML and JSON formats for API interactions. API keys are used in the HTTP header to authenticate requests.

UCS manager API interactions are XML-encoded and require a cookie in the method for authentication: This statement is true. Cisco UCS Manager APIs typically use XML for encoding interactions, and a session cookie is required for authentication after an initial login request.

Cisco Intersight API: Uses either XML or JSON formats and requires API keys for authentication.

Cisco UCS Manager API: Utilizes XML format and relies on session cookies for authentication.

References:

Cisco Intersight API Documentation

Cisco UCS Manager API Documentation

A router is a network device that routes traffic between different broadcast domains and subnets. Routers operate at the network layer (Layer 3) of the OSI model and use IP addresses to make forwarding decisions. They are responsible for determining the best path for data packets to travel across interconnected networks, ensuring that traffic is correctly directed from one broadcast domain to another.

References:

Cisco Router Basics

Broadcast Domains and Routers

=========================

1 - d, 2 - f, 3 - b, 4 - h, 5 - i, 6 – j, 7 - g, 8 - a, 9 - c, 10 - e

 Understand the JSON Structure: The JSON data given in the exhibit consists of an array of objects. Each object has a type and an items key. The items key contains an array of objects, each with a color and another items key, which is an array of strings representing items of that color.

 Analyze the Python Code: The Python code provided is:

print(filter(lambda l: l['type'] == 'fruit', vegetables)[0]['items'][0]['items'][0])

Break Down the Code:

filter(lambda l: l['type'] == 'fruit', vegetables): This line filters the JSON array vegetables to include only objects where the type is 'fruit'.

filter(...)[0]: After filtering, this selects the first object in the filtered list, which is the fruit object.

['items'][0]: This accesses the first item in the items array of the fruit object. In this case, it refers to the object where color is "green".

['items'][0]: This accesses the first item in the items array of the green object, which is "kiwi".

Evaluate the Code:

The first object of type fruit in the JSON is found.

The first item in the items array for fruit with the color green is selected.

The first item in this nested items array is "kiwi".

Therefore, the output of the given Python command is "Kiwi".

References:

Python documentation on filter: Python Docs - Filter

JSON structure understanding from DevNet Associate study materials on API interactions and data parsing.

The HTTP POST method is used by both Meraki and Webex Teams APIs to send webhook notifications. Webhooks are a way for applications to provide other applications with real-time information. The POST method is used to send data to a server to create/update a resource. In the case of webhooks, the POST request carries the event data to the endpoint URL specified by the receiving service. More details on webhooks can be found in the Meraki Webhook Documentation and Webex Teams Webhooks.

The HTTP POST method is used by both Meraki and Webex Teams APIs to send webhook notifications. Webhooks are a way for applications to provide other applications with real-time information. The POST method is used to send data to a server to create/update a resource. In the case of webhooks, the POST request carries the event data to the endpoint URL specified by the receiving service. More details on webhooks can be found in the Meraki Webhook Documentation and Webex Teams Webhooks.

NETCONF (Network Configuration Protocol) is an IETF standard protocol used for managing network devices. By default, NETCONF operates over the SSH protocol on port 830. This default port is defined to separate NETCONF traffic from other types of SSH traffic, providing a dedicated channel for network configuration tasks.

An artifact repository is a key component in a CI/CD pipeline, used to manage binary files and other artifacts produced and consumed during the build process. It helps in organizing and tracking these artifacts through various stages of the pipeline.

Provides Traceability, Search, and Management of Binary Files:

Artifact repositories store binary files and metadata, allowing developers to trace back to the source and understand the context in which an artifact was produced.

These repositories often come with search functionalities to locate specific versions of binaries quickly.

Examples include JFrog Artifactory, Nexus Repository, and AWS CodeArtifact.

Stores Files Needed and Generated During the Build Process:

Artifact repositories store intermediate and final build outputs, dependencies, libraries, and other necessary files.

These repositories support the storage and distribution of build artifacts, ensuring consistent deployment in different environments (e.g., staging, production).

Layer 2 switches use MAC (Media Access Control) addresses to direct packet transmission to the intended recipient.

MAC Address: A unique identifier assigned to network interfaces for communication on the physical network segment.

Switching: Layer 2 switches maintain a MAC address table to keep track of which MAC addresses are associated with which ports, enabling them to forward frames to the correct destination port.

Meraki APIs offer various functionalities, including:

Retrieve live streams from a Meraki Camera (A): Meraki provides API endpoints to access live video streams from its cameras, enabling integration with custom applications.

Configure network devices via the Dashboard API (C): The Meraki Dashboard API allows for comprehensive configuration and management of Meraki network devices.

References:

Cisco Meraki API Documentation (details on the capabilities of Meraki APIs)

Cisco DevNet Associate Exam Topics: APIs and Automation (understanding how to use APIs for network configuration and monitoring)

git add .

git commit -m “this is my edit”

git push

When converting XML to JSON, the structure should maintain the hierarchical organization and data representation. The provided XML structure:

10.00

9.00

8.00

20.00

12.00

translates to the following JSON structure:

{

"books": {

"science": {

"biology": "10.00",

"geology": "9.00",

"chemistry": "8.00"

},

"math": {

"calculus": "20.00",

"algebra": "12.00"

}

}

}

Root Element: The root element translates to a key "books".

Nested Elements: The and $elements\; become\; nested\; objects\; under\; "books".$

Leaf Elements: The individual subjects and their prices (e.g., 10.00) become key-value pairs within their respective parent objects.

Option A:

json

Copy code

{

"books": {

"science": {

"biology": "10.00",

"geology": "9.00",

"chemistry": "8.00"

},

"math": {

"calculus": "20.00",

"algebra": "12.00"

}

}

}

This option accurately represents the hierarchical structure of the XML data, making it the correct equivalent.

Option B, C, and D:

These options incorrectly use array notation for the nested objects, which is not consistent with the original XML structure. The XML structure indicates that "science" and "math" are single objects with multiple key-value pairs, not arrays.

References:

Converting Between XML and JSON

JSON and XML Comparison

1 – B, 2 – D, 3 – A, 4 – C

When consuming a RESTful API that returns large amounts of data, pagination is commonly used to divide the data into manageable chunks. Pagination helps reduce the load on the server and the client by providing only a subset of the total data in each response. The client can request the next set of data using parameters such as page or limit.

The provided Ansible playbook is designed to connect to an IOS router and execute the "show run" command to retrieve the current running configuration. The configuration is then registered in a variable called config. The next task copies the output stored in the config variable to a file in a specified directory on the local machine. The file is named based on the router's hostname.

Here are the steps:

Define the hosts: The playbook targets the {{ router }} group or host.

Gather facts: Enabled with gather_facts: true to collect useful information about the target devices.

Connection type: Local, meaning the playbook runs on the local machine where Ansible is invoked.

Task 1 - ios_command:

Executes the "show run" command.

Uses the provided router credentials.

Registers the command output to the config variable.

Task 2 - copy:

Takes the first element from config.stdout (the output of the "show run" command).

Copies this content to a file in /etc/ansible/configs/, naming the file command_{{ router_hostname }}.txt.

1 – C, 2 – D, 3 – B, 4 - A

When package updates from a local server fail but succeed from an external repository, it is often due to misconfiguration in the update utility. One common issue is that the update utility might be configured to use a proxy, which is not required or properly set up for internal resources. This misconfiguration can cause the update utility to fail in reaching the local server.

References:

Cisco DevNet Associate Exam Topics: Infrastructure and Automation (troubleshooting and configuring network and server environments)

Linux System Administration Documentation (details on configuring package managers and handling proxy settings)