200-901 DevNet Associate (DEVASC) Questions and Answers

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).

Edge computing involves processing data closer to where it is generated (the "edge" of the network) rather than sending it to a centralized data center or cloud for processing. This approach reduces latency and bandwidth usage, providing high-speed data processing capabilities. It is particularly beneficial for IoT implementations where real-time processing and response are crucial.

References:

Cisco DevNet Associate Study Guide: IoT and Edge Computing (Chapter 9, Section: Benefits of Edge Computing).

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'.

Load balancers distribute network or application traffic across multiple servers to ensure no single server becomes overwhelmed. In modern application deployment, load balancers allow traffic to continue smoothly as new compute units are brought online and old units are decommissioned. This ensures high availability and reliability of services.

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.

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.

For applications with significant disk I/O requirements, deploying directly on bare metal (physical servers) can provide the best performance and meet specific platform requirements.

Disk I/O Performance: Bare metal servers offer direct access to hardware resources, ensuring maximum disk I/O performance.

Automation: Modern infrastructure automation tools can fully automate the deployment, configuration, and management of bare metal servers.

Option C meets the requirements of significant disk I/O performance and full automation.

In the provided Python script, database credentials (DB_USER, DB_PWD) are stored in a JSON configuration file (config.json). While it is common to store configuration and credentials in external files, they should always be encrypted to ensure security.

Secret Management: Storing secrets such as database credentials directly in configuration files in plaintext is a security risk.

Encryption: Secrets must be encrypted to protect them from unauthorized access. This can be achieved using various methods such as encrypting the configuration file itself or using secret management tools.

Best Practices: Always ensure that sensitive information like passwords is encrypted when stored, especially in files that might be part of the source code.

Option C is the correct answer because it emphasizes the necessity of encrypting secrets if they are stored in the user database or configuration files to prevent unauthorized access.

The Cisco DevNet API documentation is the primary resource for understanding the meanings of response codes received from REST API calls. It provides comprehensive details about the API endpoints, response codes, and their interpretations, which helps developers troubleshoot and understand the responses they receive.

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 load balancer distributes incoming network traffic across multiple servers to ensure that no single server bears too much load. This helps in balancing the traffic load, improving performance, and enhancing the availability of the applications hosted on the servers.

The Dockerfile shown in the exhibit sets up an NGINX container with a delay before starting the NGINX service. It uses the ENTRYPOINT and CMD directives to define the commands that should be executed when the container starts.

ARG and ENV: These lines define and set an argument and environment variable for the delay.

ENTRYPOINT: Specifies the executable to run, in this case, /bin/sh.

CMD: Provides additional arguments to the ENTRYPOINT, which are -c and the command string to execute.

The combined command that will be executed is: /bin/sh -c "/bin/sleep 30 && nginx -g 'daemon off;'"

An engineer writes a Python script that uses two different API calls to query Cisco DNA Center for the number of interfaces on a device. The engineer notices that the two API calls produce different results. The fewer interfaces returned for the same device when the 'get_all_interfaces' API call is used can be explained by pagination.

A. times out - Incorrect. A timeout would likely result in an error, not fewer results. B. rate limit - Incorrect. Rate limiting would slow down requests but not reduce the number of returned interfaces. C. pagination - Correct. The 'get_all_interfaces' API call might be paginated, meaning it returns results in chunks rather than all at once. D. invalid password - Incorrect. An invalid password would result in an authentication error, not fewer results.

References:

Cisco DevNet DNA Center Platform

API Pagination

Using functions in code improves the development process by enabling faster code development. Functions help modularize the code, making it easier to manage, reuse, and debug, which speeds up the development process.

A. better user experience in the end product - Incorrect. This is not directly related to the use of functions in code. B. improves code performance - Incorrect. While functions can sometimes improve performance, the primary benefit is modularity and reuse. C. easier to compile the code - Incorrect. Functions do not inherently make the code easier to compile. D. faster code development - Correct. Functions make development faster by allowing code reuse and simplifying debugging.

References:

Cisco Programming Fundamentals

To ensure that changes in a file that already exists in a local repository are included in the next Git commit, the git add command must be executed. This command stages the changes in the specified file(s) so they will be included in the next commit.

A. git update - Incorrect. There is no git update command. B. git merge - Incorrect. This command is used to merge branches, not to stage changes. C. git add - Correct. This command stages changes in the working directory to be included in the next commit. D. git rebase - Incorrect. This command is used to reapply commits on top of another base tip.

References:

Git Basics - Recording Changes to the Repository

When an IP packet does not match any routes in the routing table, it is routed to the default gateway. The default gateway serves as a forwarding host that routes traffic from a local network to other networks or the Internet.

A. firewall - Incorrect. A firewall is a security device, not used for routing unmatched packets. B. load balancer - Incorrect. A load balancer distributes network or application traffic across multiple servers, not used for routing unmatched packets. C. central switch - Incorrect. A switch operates at the data link layer and does not perform IP routing. D. default gateway - Correct. The default gateway is used to route packets that do not match any other route in the routing table.

References:

Cisco Network Fundamentals

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.

In the response header shown, the "Content-Type" is specified. Response headers provide important metadata about the response, including the content type, which informs the client about the nature of the returned content (in this case, application/json).

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

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 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.

SSH (Secure Shell) is a protocol that provides a secure channel over an unsecured network by using encryption. It operates over TCP port 22 and is commonly used for remote login and command execution on network devices and servers. SSH ensures secure communication between the client and server by encrypting the session.

References:

Cisco DevNet Associate Study Guide: Understanding Network Protocols (Chapter 2, Section: Common Network Protocols and Ports).

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

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).

NETCONF (Network Configuration Protocol) allows for the exchange of configuration data and state information between a network device and a management system using XML-encoded messages over a secure SSH connection.

A. allows Python scripts to be executed externally from a network device - Incorrect. This is not a capability of NETCONF. B. uses JSON to encode data in its content layer - Incorrect. NETCONF uses XML for encoding data. C. allows XML messages to be exchanged via the SSH protocol - Correct. NETCONF uses XML to encode configuration data and state information, and it uses SSH as the transport protocol. D. exposes a web-based interface - Incorrect. NETCONF itself does not provide a web-based interface; it operates over SSH.

References:

NETCONF Protocol

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.

VLANs (Virtual Local Area Networks) provide multiple benefits, including segmenting the broadcast domain, which reduces unnecessary traffic and improves network performance. They also enable the logical grouping of devices across different physical Layer 2 switches, enhancing network management and security by isolating traffic between different VLANs.

References:

Cisco DevNet Associate Study Guide: Network Segmentation and VLANs (Chapter 4, Section: Understanding VLANs and Their Benefits).

Top of Form

Bottom of Form

The HTTP response code 204 No Content indicates that the server successfully processed the request, but there is no content to send in the response. This status code is typically used when a request is successfully handled, but no additional information needs to be returned to the client.

References:

Cisco DevNet Associate Study Guide: HTTP Status Codes (Chapter 7, Section: Common HTTP Response Codes).

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

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.

To restrict access to the management interface of devices using SSH and HTTPS, the correct ports need to be included in the ACLs.

Port 22: Used by SSH (Secure Shell) for secure remote login and command execution.

Port 443: Used by HTTPS (Hypertext Transfer Protocol Secure) for secure web traffic.

Options A and D are correct as they are the standard ports for SSH and HTTPS.

Simulation Environment: CML provides a realistic environment for testing network configurations and automation scripts before deploying them on actual devices.

Resource Verification: Engineers can use CML to ensure that their Ansible playbooks function correctly and make necessary adjustments before running the code in a live network.

Option D is the correct resource for verifying the code using a simulated network environment.

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

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 exhibit shows the router configuration for NAT (Network Address Translation). To allow traffic from the security cameras to access the Internet, the access list needs to include a permit statement for the 192.168.10.0/24 subnet.

Access List Configuration: The access list (ACL) should permit traffic from the security camera VLAN (192.168.10.0/24).

NAT Configuration: The NAT configuration uses an ACL to determine which internal IP addresses are translated to the public IP address pool.

Missing Permit Statement: Without a specific permit statement for the 192.168.10.0/24 subnet, the router does not translate the IP addresses from this subnet, resulting in a lack of Internet access for the security cameras.

References:

Cisco NAT Configuration Guide: NAT Configuration

Comprehensive Detailed Step by Step Explanation with ReferencesA sandbox environment is an isolated testing environment that mimics a live network. It allows engineers and developers to run scripts and test code without affecting the production network. Cisco provides sandboxes through the DevNet portal, which are always available for testing and experimentation with network automation and programmability. Using a sandbox helps monitor the live execution of code in a controlled and safe manner, ensuring that any potential issues do not impact the actual network.

References:

Cisco DevNet Sandboxes

Cisco DevNet Associate Certification Guide

The provided Bash script performs the following steps:

Adds a new user with useradd.

Adds a new group with groupadd.

Creates a directory /opt/scripts.

Copies all Python scripts (*.py) to the /opt/scripts directory.

Changes to the /opt/scripts directory.

Lists the Python scripts and processes each script in a loop.

Within the loop, the script:

Appends the script name to a file content.txt.

Assigns execution privileges to the script (chmod u+x).

Changes the ownership of the script to the newly created user and group (chown $1:$2).

This workflow automates the process of setting execution permissions for the owner (the newly created user) and assigning the user and group ownership to the scripts. It also stores the script names in content.txt.

References:

Cisco DevNet Associate Certification Guide

Bash Scripting Documentation

In Test-Driven Development (TDD), the process starts with writing tests before writing the actual code. The primary purpose of running tests before writing the code is to ensure that the tests fail initially. This failure demonstrates that the tests are correctly identifying the absence of the desired functionality or the presence of bugs. Once the tests are verified to fail for the expected reasons, the developer then writes the minimal code necessary to pass the tests, ensuring that the new functionality works as intended and that the codebase is continuously tested.

References:

Test-Driven Development by Example

Cisco DevNet Associate Certification Guide

A code review process involves evaluating and examining another developer's code to identify potential issues, bugs, and improvements before the code is merged into the main codebase. It helps in maintaining code quality and catching errors early in the development cycle.

Error Detection: Code reviews help detect and eliminate common mistakes and bugs that developers might overlook.

Knowledge Sharing: They promote knowledge sharing and learning among team members.

Code Quality: Ensures that the code adheres to the coding standards and best practices.

Option D is correct as the primary benefit of code reviews is to eliminate common mistakes during development.

During the integration step of the CI/CD pipeline, code from multiple developers is combined. This step involves compiling the code and running tests to ensure that the different components work together correctly. It is a critical phase for identifying integration issues early in the development cycle.

Infrastructure as Code (IaC) applies software development practices to infrastructure management. This approach uses code to provision and manage IT infrastructure, enabling version control, automated testing, and continuous delivery.

Automated Provisioning: IaC scripts automate the setup and configuration of infrastructure resources.

Consistency: By defining infrastructure in code, environments can be consistently reproduced across different stages (development, testing, production).

Development Practices: IaC allows infrastructure to be managed with the same tools and processes as application code, including version control and automated testing.

References:

Infrastructure as Code Overview: IaC Introduction

The HTTP 401 Unauthorized error indicates that the request lacks proper authentication credentials. However, in this case, the credentials are provided, so the issue likely stems from a missing or incorrect header. The Content-Type header is necessary for many REST APIs to specify the format of the request body. Adding the Content-Type: application/yang-data+json header ensures that the server correctly interprets the request as JSON formatted data according to the YANG data model.

References:

Cisco DevNet Associate Certification Guide

Cisco IOS XE RESTCONF API Documentation

The Dynamic Host Configuration Protocol (DHCP) is responsible for automatically assigning IP addresses to devices on a network. When a device connects to the network, it sends a broadcast request for an IP address, and a DHCP server responds with an IP address, subnet mask, default gateway, and DNS server information. This process simplifies network administration by automating IP address assignment and ensuring that devices have unique IP addresses without manual configuration.

References:

Cisco DHCP Overview

RFC 2131: DHCP

Cisco SD-WAN (Software-Defined Wide Area Network) is a solution designed to optimize and secure connectivity across various networks. It provides several advantages including cost reduction from MPLS (Multiprotocol Label Switching), improved application performance by leveraging multiple types of connections (broadband, LTE, etc.), and simplified operations through centralized management.

Cost Reduction from MPLS: Cisco SD-WAN allows enterprises to utilize less expensive broadband internet connections alongside MPLS. This hybrid approach reduces dependency on costly MPLS circuits, significantly lowering WAN costs.

Improved Application Performance: By using application-aware routing, SD-WAN directs traffic across the best available path, ensuring better performance for critical applications.

Simplified Operations: Cisco SD-WAN centralizes network management and policy implementation, simplifying network operations and reducing the complexity associated with traditional WANs.

References:

Cisco SD-WAN Documentation: Cisco SD-WAN

A hybrid cloud deployment model combines elements of both private and public clouds, providing the scalability needed for fast deployment of new nodes for data and indexing. It allows for sensitive information to be stored in a private cloud where specialist encryption tools can be used, while non-sensitive data can be stored in the public cloud to take advantage of its scalability and cost benefits. This approach meets the requirements of both scalability and data security.

Ansible is a powerful automation tool used for IT tasks such as configuration management, application deployment, and task automation. In the context of the exhibit, Ansible can be used to automate the removal of a Cisco Meraki device from the network and retrieve device information.

Device Management: Ansible modules, such as the meraki_device module shown in the exhibit, allow for the management of Meraki devices. Tasks can include querying device information and changing the state of the device.

Automation with Playbooks: The Ansible playbook in the exhibit demonstrates how to authenticate, define the organization and network, and manage the device state (query or absent).

Task Execution: The playbook is structured to perform tasks using a loop (with_items) to execute actions such as querying device details and removing the device (absent state).

References:

Ansible Documentation for Meraki Modules: Ansible Meraki Modules

To obtain a token from the Cisco DNA Center API using HTTP Basic Authentication, the requests library in Python is used. The missing line of code in the snippet should set up HTTP Basic Authentication as follows:

auth=HTTPBasicAuth(user,password)

HTTPBasicAuth: This is a class from the requests.auth module that handles HTTP Basic Authentication.

user, password: These are the credentials required for authentication.

The correct line of code that completes the script to obtain a token from Cisco DNA Center API is:

python

Copy code

auth=HTTPBasicAuth(user,password)

References:

Requests Library Documentation - HTTPBasicAuth

Cisco DevNet Associate Certification Guide

Bandwidth is the network constraint that affects the performance of an application as the number of users accessing the application increases. Bandwidth refers to the maximum rate of data transfer across a network path. If the bandwidth is insufficient to handle the increased traffic, the application performance will degrade, leading to slower response times and potential timeouts.

References:

Cisco DevNet Documentation - Network Performance

Cisco DevNet Associate Certification Guide

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."

Organizing code into modules improves maintainability by encapsulating functionality into smaller, more manageable pieces. This modular approach allows developers to focus on specific sections of code without being overwhelmed by the entire codebase. It also makes it easier to debug, test, and update parts of the application independently, enhancing overall code quality and maintainability.

References:

Modular Programming - Python Documentation

Deploying applications in a public cloud provides several advantages, especially for developers dealing with temporary data processing and secure storage:

Ease in Infrastructure Management: Public cloud services offer managed infrastructure, which significantly reduces the operational burden on developers. They do not need to worry about hardware maintenance, scaling, or other infrastructure-related tasks.

Scalability: Public clouds provide scalable resources, allowing developers to adjust their infrastructure needs dynamically as per the workload requirements.

Cost-Effectiveness: Public clouds often operate on a pay-as-you-go model, which can be more cost-effective for temporary or variable workloads.

References:

Cisco DevNet Associate Certification Guide

General public cloud service provider documentation (e.g., AWS, Azure, Google Cloud)

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

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.

The block of code that correctly completes the script should handle timeout exceptions and print the error, as well as print the response body if the HTTP status code is 200. Option A achieves this:

import requests

url = 'https://api.meraki.com/api/v0/networks/net1/httpServers '

headers = { 'Accept': 'application/json' }

response = requests.get(url=url, headers=headers, verify=False, timeout=5)

try:

response = requests.get(url, headers=headers, verify=False, timeout=5)

response.raise_for_status()

except requests.Timeout as e:

print("Timeout Error: {}".format(e))

if response.status_code == 200:

print(response.text)

This code makes a GET request to the specified URL, handles the timeout exception by printing a message, and prints the response body if the status code is 200.

References:

Requests: Handling Timeouts

Python Requests: Response Status Code

The developer can use the Cisco DevNet API documentation to get detailed information on how to use the API for automated data collection from Webex. The API documentation includes comprehensive guides, usage examples, and authentication methods such as HTTP basic authentication. This resource helps developers understand the data formats (JSON or XML) and provides code snippets and best practices for implementation. Cisco DevNet API documentation is designed to assist developers in integrating their applications with Cisco's APIs effectively.

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

<admin-status>1</admin-status>

1

408164820

728061

In the context of the Firepower Management Center (FMC) REST API, the string "f413afeb-e6f6-75f4-9169-6d9bd49s625e" represents the unique identifier (UUID) for a specific upgrade package. This UUID is used to uniquely identify and reference the upgrade package when performing operations through the API.

The provided diff format shows changes between two versions of a file. The + signs indicate lines that have been added in the new file (new.py). The code snippet that belongs to the new file is the one with + signs, showing the addition of code to print the device list filtered by hostname. The added lines include printing the message and setting the query_string_params to filter by hostname.

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

The provided JSON configuration includes information about a GigabitEthernet interface with the name "2". To retrieve information about this specific interface using a RESTCONF API call, the correct HTTP method and URL must be used.

HTTP Method: The GET method is used to retrieve information from the server.

Correct URL: The URL must specify the path to the particular interface. The correct URL structure includes the native and interface resources, followed by the interface type (GigabitEthernet) and its specific name ("2").

The correct RESTCONF API call to retrieve the information would be:

GET https://devnetlab.local/restconf/api/running/native/interface/GigabitEthernet/2/

This URL correctly targets the specific GigabitEthernet interface named "2" in the running configuration.

References:

Cisco RESTCONF API Documentation: RESTCONF API Guide

A MAC (Media Access Control) address is a unique identifier assigned to network interfaces for communications at the data link layer of a network segment. Key features of a MAC address include:

Length and Format: A MAC address is 48 bits in length, typically represented as 12 hexadecimal digits (e.g., 00:1A:2B:3C:4D:5E).

Hexadecimal Representation: The 12 hexadecimal digits are often grouped into pairs separated by colons or hyphens for readability (e.g., 00:1A:2B:3C:4D:5E or 00-1A-2B-3C-4D-5E).

References:

IEEE 802 MAC Address Standard

Cisco MAC Address Basics

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.

DNS (Domain Name System) is the technology responsible for matching a name to an IP address of an application running on a host. When a user types a domain name into a browser, DNS translates that domain name into the corresponding IP address, enabling the user's device to connect to the server hosting the application.

References:

Cisco DevNet Documentation - DNS

Cisco DevNet Associate Certification Guide

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

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

GIT PUSH

To start a CI/CD pipeline and run automated tests after modifying the code in a cloned repository, the appropriate command is git push. When a developer pushes the changes to the remote repository, it triggers the CI/CD pipeline configured in the repository. Here are the steps:

Clone the repository from GitLab.

Make the necessary code modifications.

Use git commit to commit the changes locally.

Use git push to push the committed changes to the remote repository.

Pushing the changes to the remote repository initiates the CI/CD pipeline, which typically includes steps like building the application, running tests, and deploying the application if tests pass.

References:

Cisco DevNet Associate Certification Guide

GitLab CI/CD Documentation

Cisco Firepower has an API that allows the capability to obtain a list of vulnerable software on user devices. Firepower Management Center (FMC) provides APIs for vulnerability management and allows security teams to query and analyze the vulnerabilities detected on endpoints and network devices.

A firehose webhook in the context of Cisco Webex allows an application to receive real-time data updates about events happening within Cisco Webex. It enables the application to subscribe to a stream of data, ensuring that the application receives immediate notifications about any updates or changes in the Webex environment. This is particularly useful for integrating Webex functionalities into other applications and ensuring they are synchronized with the latest data.

References:

Cisco DevNet Associate Certification Guide

Cisco Webex API Documentation

The EXPOSE instruction in a Dockerfile informs Docker that the container listens on the specified network ports at runtime.

EXPOSE Instruction: It does not publish the port but indicates to Docker that the application inside the container uses this port.

Listening Port: The Docker container will be configured to listen on port 5000 using EXPOSE 5000.

References:

Dockerfile Reference: Dockerfile EXPOSE

import requests

data = {

"id": 11,

"summary": "Request summary"

}

response = requests.post('https://todolist.example.com/tasks/ ', json=data)

if response.status_code != 201:

raise ApiError('POST /tasks/ {}'.format(response.status_code))

for item in response.json():

print('{} {}'.format(item['id'], item['summary']))

Importing the Requests Library:

The requests library is used to make HTTP requests in Python. It is a popular third-party library that simplifies interactions with web APIs.

Creating the Data Payload:

The data dictionary contains the information to be sent in the body of the POST request. It includes an id and a summary.

Making the POST Request:

The requests.post method is used to send a POST request to the specified URL (https://todolist.example.com/tasks/). The json=data parameter automatically converts the data dictionary to a JSON-formatted string and sets the appropriate headers.

Checking the Response Status Code:

The script checks if the status_code of the response is not equal to 201. A status code of 201 indicates that the request was successful and a resource was created.

If the status code is not 201, an ApiError is raised with a message that includes the status code.

Processing the JSON Response:

The response.json() method is used to parse the JSON response into a Python dictionary.

The script iterates over the items in the JSON response and prints the id and summary of each item.

References:

Cisco DevNet Associate Certification Guide, Sections on interacting with REST APIs using Python

Official documentation for the Requests library: Requests: HTTP for Humans

loads() function is present in python built-in 'json' module. This function is used to parse the JSON string.

RFC 1918 defines private IP address ranges for use within private networks. The address space 172.16.0.0 to 172.31.255.255 is designated as private and falls under class B.

Class B Address Space: The range 172.16.0.0 to 172.31.255.255 is a private IP address range designated for class B networks.

Subnet Mask: A subnet mask of 255.255.0.0 (/16) is commonly used within this range to create subnets.

References:

RFC 1918 Address Allocation: RFC 1918

gRPC = C, NETCONF = A, RESTCONF = B, D

OR

 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.

By segmenting the network into separate subnets for clients and servers, you can control the types of traffic that flow between these segments using access control lists (ACLs) and firewall rules. This can enhance security by limiting access to critical server resources and reducing the risk of unauthorized access.

Subnets will split domains to limit failures (Option C):

Segmenting the network into different subnets helps contain network issues within a specific segment, preventing them from affecting the entire network. This approach improves network stability and reliability, as issues in the client subnet will not impact the server subnet and vice versa.

References:

Cisco Subnetting and Network Segmentation

Cisco Router and ACL Configuration Guide

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Option A correctly creates a handle instance using the UcsHandle class from the UCS SDK in Python. The correct instantiation requires providing the IP address, username, password, port number, and secure connection parameters as per the documented API.

The correct code snippet is:

from ucsmsdk.ucshandle import UcsHandle

handle = UcsHandle("10.1.2.254", "admin", "password", port="443", secure=True)

This snippet matches the API documentation requirements:

ip: The IP or hostname of the UCS Server.

username: The username as configured on the UCS Server.

password: The password as configured on the UCS Server.

port: The port number to be used during the connection.

secure: True for a secure connection.

References:

UCS Python SDK Documentation (provides details on how to use UcsHandle)

Cisco DevNet Associate Exam Topics: Infrastructure and Automation (understanding how to use APIs and SDKs for automation)

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

A firewall is a network device that monitors incoming and outgoing traffic and decides whether to allow or block specific traffic based on a defined set of rules.

Function of a Firewall:

Traffic Monitoring: It continuously monitors all traffic passing through it.

Rule-Based Filtering: It applies predefined security rules to allow or deny traffic.

Protection: It protects networks from unauthorized access and cyber threats.

Comparison with Other Devices:

Switch: A network device that connects devices within a LAN and uses MAC addresses to forward data to the correct destination.

Load Balancer: Distributes network or application traffic across multiple servers to ensure no single server becomes overwhelmed.

Reverse Proxy: A server that sits in front of web servers and forwards client requests to those web servers.

Therefore, a firewall is the correct answer because it specifically monitors and filters network traffic based on security rules.

References:

Cisco Firewalls Overview: Cisco Firewall Products

In the exhibit, the unified diff output shows changes made to the single_request_timeout method in a Python script. The modifications include:

Removing the assert statement that checks if the value is None or greater than 0.

Adding a raise ValueError statement to ensure that the single_request_timeout must be a positive integer if the value is not None.

These changes can be seen in the sections labeled with @@ -160,11 +160,12 @@ indicating the lines in the original and modified files. The lines starting with - indicate removed lines, and those starting with + indicate added lines. This type of change is typical in code updates to improve validation and error handling.

Check below the answer exact.

Edge computing solutions are utilized where low latency is needed. Edge computing involves processing data closer to where it is generated (at the edge of the network), which reduces the latency compared to sending data to a centralized data center for processing.

Low Latency Needs: Edge computing is designed to provide real-time data processing and decision-making by reducing the distance data has to travel. This is crucial for applications requiring immediate data processing, such as IoT devices, autonomous vehicles, and real-time analytics.

References: Cisco DevNet Associate Certification Guide, Chapter on IoT and Edge Computing.

Network programmability allows for automated, scalable, and replicable network provisioning and management. This reduces the need for manual configuration, minimizes human errors, and enables the implementation of consistent network policies across multiple devices and environments. By leveraging APIs and automation tools, network operations become more efficient and can easily adapt to changes in the network.

Code review is typically performed before the merge of code in a version control system. This process involves examining code changes to ensure they meet the required standards, are free of bugs, and align with the project’s goals. The review usually happens after code has been committed to a feature branch but before it is merged into the main branch. This helps maintain the integrity of the main branch and ensures that any issues are caught early. More information can be found in best practices for code review.

1 – D, 2 – C, 3 – A, 4 – B

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)

 Asynchronous API calls are non-blocking, meaning the application can continue processing other tasks while waiting for the API call to complete. This helps improve the efficiency and responsiveness of the application. Typically, a callback function is used to handle the response once the API call completes.

Option B is correct because asynchronous API calls do not block the code; they allow the application to perform other operations concurrently.

Option E is correct because a callback function is usually implemented to handle the response of an asynchronous API call once it completes.

References:

Cisco DevNet Associate Exam Topics: APIs and Automation (understanding synchronous and asynchronous API calls)

Asynchronous Programming Documentation (explains how asynchronous calls work and the use of callbacks)

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.

DNS (Domain Name System) is the service that provides a directory lookup for IP addresses and host names. DNS translates human-readable domain names (like www.example.com ) into IP addresses that computers use to identify each other on the network.

DNS: Converts domain names into IP addresses and vice versa.

DHCP: Dynamically assigns IP addresses to devices on a network.

SNMP: Used for network management and monitoring.

NAT: Translates private IP addresses to a public IP address for accessing the internet.

References:

Cisco DNS Documentation

DevOps emphasizes collaboration between development and operations teams, breaking down organizational silos to improve workflow and communication (C). Additionally, DevOps focuses on automating processes to increase efficiency, reduce manual effort, and minimize errors, often prioritizing automation over extensive documentation (E).

References:

Cisco DevNet Associate Exam Topics: DevOps Practices and Principles (understanding the core principles of DevOps)

"The Phoenix Project" by Gene Kim, Kevin Behr, and George Spafford (explains the importance of cross-functional teams and automation in DevOps)

1 – B, 2 – E, 3 - F

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)

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.

To prepare the file README.md in the working tree for the next commit operation in Git, the command git add README.md should be used. This command stages the file, meaning it adds the file's current content to the staging area, which is a preparatory step before committing it to the repository.

git add README.md: Adds the README.md file to the staging area.

git commit README.md: Commits all staged changes (not just README.md unless it is the only file staged).

References: Pro Git book by Scott Chacon and Ben Straub, Git documentation.

To delete a directory and all of its contents (including read-only files) recursively without prompting for confirmation, the rm command with the -rf flags should be used.

rm -r: This option tells rm to remove directories and their contents recursively.

rm -f: This option tells rm to force the removal of files, ignoring nonexistent files and never prompting for confirmation.

Therefore, the correct command is rm -rf old_project. This command will recursively remove the old_project directory and all its contents without any confirmation prompts, regardless of file permissions.

References: Cisco DevNet Associate Certification Guide, Chapter on Linux and Bash Commands.

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

Synchronous API Operations:

Immediate Response: In a synchronous operation, the client sends a request to the server and waits for an immediate response. The client cannot proceed until it receives this response.

Blocking Call: The call is considered blocking, meaning the client application is blocked from performing other tasks until the response is received.

Use Case: This is useful when the result of the operation is required immediately to continue the workflow.

Asynchronous API Operations:

Delayed Response: In an asynchronous operation, the client sends a request to the server and does not wait for an immediate response. Instead, it continues its processing and can check back later for the result.

Non-blocking Call: The call is non-blocking, allowing the client to perform other tasks while waiting for the server to complete the operation.

Polling and Webhooks: Clients may poll the server for status updates or subscribe to a webhook to be notified when the operation is complete.

Task ID: The server may provide a task ID in the response that can be used to check the status of the operation later.

References:

Cisco DevNet API Documentation: API Design Guide

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 <script>alert('I want to pass the DevNet Associate Exam.');</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.

Cisco Advanced Malware Protection (AMP) provides APIs that can be used to obtain a list of vulnerable software on user devices. AMP for Endpoints offers extensive capabilities for threat detection and response, including the ability to query for vulnerabilities. These APIs allow developers to integrate vulnerability information into their applications, enabling proactive security measures. Detailed information on using AMP APIs can be found in the Cisco AMP for Endpoints API documentation.

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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.

When a developer encounters many lines of code doing repetitive tasks, refactoring the code to use functions is a standard practice. This reduces code duplication and enhances readability and maintainability. Functions encapsulate repetitive logic, making the code cleaner and more organized.

The docker run -p 3000:5000 command maps port 3000 on the host to port 5000 on the Docker container. This means that any process on the host that wants to access the service running inside the container should connect to port 3000 on the host. The service inside the container listens on port 5000, but from the host's perspective, it will be accessed via port 3000. More information on Docker port mapping can be found in the Docker documentation.

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

The HTTP status code 400 (Bad Request) is used by a REST API to indicate that the server cannot or will not process the request due to something that is perceived to be a client error (e.g., malformed request syntax, invalid request message framing, or deceptive request routing).

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).

Functions in programming are a fundamental concept that provide several key benefits:

Modularity: By breaking down a program into smaller, manageable functions, it becomes easier to understand, debug, and maintain.

Reusability: Functions allow code to be reused across the program, reducing redundancy.

Abstraction: Functions can abstract complex operations into a simple function call, making the code easier to read and understand.

Testing: Functions can be tested individually, which simplifies the process of testing the overall program.

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

<algebra>12.00</algebra>

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

For Basic Authentication in REST APIs, the Base64 encoded credentials must be included in the header of the HTTP request. The correct method is to include the following header in the request:

Authorization: Basic am9objowMTlzNDU2Nzg=

References: Cisco DevNet Associate Certification Guide, Chapter on REST API Authentication methods.

The HTTP status code 200 indicates successful execution of a request.

Status Code 200:

Meaning: OK - The request has succeeded. The meaning of the success depends on the HTTP method:

GET: The resource has been fetched and is transmitted in the message body.

HEAD: The headers are in the message body.

POST: The resource describing the result of the action is transmitted in the message body.

TRACE: The message body contains the request message as received by the server.

Comparison with Other Codes:

404 - Not Found: The server can’t find the requested resource.

405 - Method Not Allowed: The request method is known by the server but is not supported by the target resource.

500 - Internal Server Error: The server encountered an unexpected condition that prevented it from fulfilling the request.

Thus, the status code 200 indicates that the request was successful.

References:

HTTP Status Codes: MDN Web Docs

Clients make several types of queries to DNS servers. The two relevant types here are:

AAAA: This query type requests the IPv6 address associated with a domain name.

PTR: This query type is used for reverse DNS lookups, where it maps an IP address to a domain name.

AAAA (Quad-A) records store IPv6 addresses of a domain.

PTR (Pointer) records are used in reverse DNS lookups to map IP addresses to the corresponding domain names.

References: DNS and BIND by Cricket Liu and Paul Albitz, Cisco DevNet Associate Certification Guide.

VLANs (Virtual Local Area Networks) serve several purposes in a network. Two primary purposes are:

Segmentation of the Network: VLANs logically segment a network into different broadcast domains, which helps in managing and controlling broadcast traffic. This segmentation helps improve performance and security by isolating certain types of traffic from others.

Creating Broadcast Domains: Each VLAN is a separate broadcast domain. By using VLANs, a network administrator can reduce the size of broadcast domains, thereby reducing broadcast traffic and increasing the efficiency of the network.

These purposes are in line with Cisco's network design principles and best practices for using VLANs. References: Cisco DevNet Associate Certification Guide, Chapter on VLANs and their uses.

There are two primary types of NAT (Network Address Translation) used in networking:

Static NAT: Maps a single private IP address to a single public IP address. This type of NAT is useful when you want a specific internal device (like a server) to be accessible from the internet using a consistent public IP address.

Dynamic NAT: Maps a private IP address to a public IP address from a pool of available public IP addresses. This type of NAT is used when you want internal devices to access the internet but do not require a consistent public IP address for each internal device.

Other types mentioned (Normal NAT, Multicast NAT, Router NAT) are not standard terms or widely recognized types of NAT.