Cisco 200-901 DevNet Associate (DEVASC) Exam Practice Test

Cisco Finesse offers several capabilities:

Browser Access: Agents can access Finesse directly from a browser, eliminating the need for any client-side installation or configuration. This simplifies deployment and maintenance.

Gadget Containers: Finesse provides a single user interface that integrates multiple gadget containers, allowing for a seamless and unified experience.

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 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 authenticating a RESTCONF API session with a router running Cisco IOS XE Software, basic authentication is required. This involves sending a username and password encoded in Base64 as part of the HTTP headers.

Cisco DNA Center is a comprehensive network management and command center for enterprise networks, providing centralized management, automation, security, and policy enforcement across both wired and wireless networks.

Cisco ACI: Primarily focuses on data center automation and policy enforcement.

Cisco DNA Center: Provides organization-wide automation, security, and policy enforcement capabilities for both wired and wireless networks.

Cisco Umbrella: Offers cloud security services.

Cisco SD-WAN: Focuses on software-defined wide-area networking solutions.

Cisco DNA Center is designed to bring agility and operational efficiency across the entire enterprise network by leveraging advanced automation and assurance capabilities.

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

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 leverages models to represent the desired state of network configurations, allowing for programmatic and standards-based management. This approach ensures that configurations can be written consistently and automatically across different network devices, simplifying network management and reducing the risk of configuration errors.

References:

Cisco DevNet Associate Study Guide: Model-Driven Programmability (Chapter 5, Section: Benefits of Model-Driven Programmability).

A VLAN (Virtual Local Area Network) allows devices on one or more LANs to be grouped together as if they were on the same physical network, even if they are not.

Logical Segmentation: VLANs provide logical segmentation of networks, enabling devices to communicate as if they are on the same physical network.

Isolation and Flexibility: They offer isolation and flexibility in network design, improving security and reducing broadcast domains.

Option B is correct as VLANs create logical groupings of devices that communicate as if they are on the same physical LAN.

Cisco Umbrella provides cloud-delivered security that includes malware and content filtering through DNS. It is designed to block malicious domains, IP addresses, and URLs before they can reach your network or endpoints.

DNS-Layer Security: Cisco Umbrella uses DNS to prevent connections to known malicious sites by blocking the DNS request, thereby preventing the initiation of malicious connections.

Content Filtering: It also provides content filtering to block inappropriate or non-business-related websites based on customizable policies.

Option D is the correct answer because Cisco Umbrella is specifically known for its DNS-layer security capabilities, including malware and content filtering.

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).

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).

Common data formats like JSON and YAML are typically parsed into a Python dictionary. This is because dictionaries in Python provide a way to store data in key-value pairs, which is similar to the structure of these data formats.

A. sequence - Incorrect. This is a general term that includes lists, tuples, etc. B. set - Incorrect. A set is an unordered collection of unique elements, which is not suitable for key-value pairs. C. dictionary - Correct. Dictionaries are used to store data in key-value pairs. D. list - Incorrect. Lists are ordered collections of items, which are not suitable for key-value pairs.

References:

Python Data Structures

JSON and YAML Parsing

When selecting the "best route" for a network device to reach its destination, the considerations include:

Metrics: These are values used by routing protocols to determine the best path to a destination. Metrics can include factors like hop count, bandwidth, delay, load, and reliability.

Administrative Distance: This is a value used to rate the trustworthiness of the source of the routing information. Lower values indicate more trusted routes.

The Waterfall method is a sequential software development process where a phase begins only after the previous phase has ended. In contrast, Agile development involves iterative processes where phases run in parallel and are continuously improved upon.

A. Waterfall increases agility to implement faster while Agile promotes reliability - Incorrect. This is the opposite of the typical characteristics of these methods. B. A phase begins after the previous phase has ended in Waterfall while Agile phases run in parallel - Correct. Waterfall is linear and sequential, while Agile is iterative and parallel. C. Customers get feedback during the process in Waterfall while they can see the result at the end in Agile - Incorrect. Agile involves continuous feedback, whereas Waterfall typically provides feedback only at the end. D. Requirements can be updated in Waterfall while in Agile it should be gathered in the beginning - Incorrect. Requirements in Agile can be updated continuously, while Waterfall requires requirements to be defined upfront.

References:

Waterfall vs. Agile Methodologies

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.

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

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 EXPOSE instruction in a Dockerfile informs Docker that the container listens on the specified network ports at runtime. This does not publish the ports to the host machine, but it allows them to be connected to from other containers.

A. Local port 8080 of the container that launched with this docker image is accessible from co-hosted containers and external clients - Incorrect. The EXPOSE instruction does not make the port accessible to external clients. B. Local port 8080 is not reachable at all because no IP address is specified along with the EXPOSE command of the Dockerfile - Incorrect. The EXPOSE instruction does not require an IP address. C. Local port 8080 is accessible from other containers running on the same docker host as the container that launched with this docker image - Correct. The EXPOSE instruction makes the port available for inter-container communication. D. Local port 8080 of the container that launched with this docker image is accessible to external clients - Incorrect. The EXPOSE instruction does not publish the port to external clients.

References:

Dockerfile reference - EXPOSE

A reverse proxy can be used to route external requests to different applications on the same host machine using a single public IP address and port. It forwards the requests to the appropriate backend servers based on the request URL or other routing rules.

Single Entry Point: A reverse proxy serves as a single entry point to multiple applications, making it ideal for managing traffic to multiple services hosted on the same machine.

Routing Requests: It can route requests to different internal ports based on the requested URL or other criteria.

Option A is the correct choice as a reverse proxy handles external access to multiple applications on the same host.

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.

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 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.

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.

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 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 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'.

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.

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

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

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.

In test-driven development (TDD), the "green bar" refers to the visual indication that all tests have passed, typically seen in a testing framework. Two of the patterns that developers use to reach the green bar in TDD are "triangulate" and "fake it."

A. another test - This is not a green bar pattern; it's a step in the TDD cycle but not a pattern for passing tests. B. break - This is not a TDD pattern. C. triangulate - Correct. Triangulation involves adding another test to force the implementation to be more generic and robust. D. starter test - This is not a TDD pattern. E. fake it - Correct. Faking it means to return a simple, hard-coded value to make the test pass.

References:

Test-Driven Development (TDD) Patterns

Growing Object-Oriented Software, Guided by Tests

The provided Ansible playbook automates the process of ensuring the nginx server is installed while removing apache2, and then updates all the packages to their latest versions.

Task 1: Ensures that apache2 is uninstalled (state: absent).

Task 2: Ensures that nginx is installed (state: present).

Task 3: Updates all packages to their latest versions (state: latest).

Option C accurately describes the process automated by the Ansible playbook.

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 = ' '

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

In the given network topology, the load balancer's primary role is to distribute incoming requests to the application servers. This ensures that no single server is overwhelmed, and it helps in providing high availability and reliability for the hosted applications.

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.

In the provided network topology, Device E is positioned between Server 1 and Server 2. Device E, being a Layer 2 switch, will limit traffic between these servers by making forwarding decisions based on MAC addresses. If there are VLANs configured, Device E will ensure that traffic is segregated accordingly, allowing only specific traffic to pass between the servers as defined by the network policies.

References:

Cisco DevNet Associate Study Guide: Network Components (Chapter 2, Section: Switches and Their Role in Network Traffic Management).

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.

Jitter refers to the variation in packet arrival times, which can cause packets to arrive out of order, leading to choppy audio or dropped parts of a conversation in real-time VoIP applications. Latency and delay refer to the time it takes for a packet to travel from source to destination, and capacity refers to the bandwidth available, but jitter specifically affects the consistency of packet delivery timing, which is critical for VoIP quality.

References:

Cisco DevNet Associate Study Guide: QoS and Network Performance (Chapter 8, Section: Understanding Jitter and Its Effects).

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.

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.

YANG model-driven programmability allows for the configuration of devices using data models. In NX-OS, this includes both native and OpenConfig-based models.

YANG Models: These are used to model configuration and state data for network devices. Native models are specific to the vendor, while OpenConfig models are vendor-neutral.

Configuration Management: YANG models facilitate consistent and programmable configuration of network devices, which can be done through APIs like NETCONF or RESTCONF.

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.

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.

A platform that runs directly using a hypervisor is referred to as a virtual machine (VM). A hypervisor, also known as a virtual machine monitor (VMM), is software that creates and runs VMs. It allows multiple VMs to share the hardware resources of a physical host, providing isolation and resource management for each VM.

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.

The Bash script shown performs the following actions:

It reads a directory name into the variable ndir.

It enters a loop that continues as long as the directory specified by ndir exists (-d "$ndir" checks if a directory exists).

Inside the loop, it changes the current directory to ndir.

Once the loop exits (when a directory with the name ndir no longer exists), it creates a new directory with the name stored in ndir.

Thus, the script ensures that it continues to navigate into directories with the given name until it finds one that does not exist, and then creates it.

YANG (Yet Another Next Generation) is a data modeling language used to model configuration and state data manipulated by the NETCONF protocol. Here are two advantages of YANG-based approaches for infrastructure automation:

Multi-platform vendor abstraction (Option B):

YANG provides a standardized way to model configuration and state data, enabling multi-platform vendor abstraction. This means that network engineers can write configurations and management scripts that work across different network devices from different vendors, as long as they adhere to the YANG model. This reduces the complexity and increases the interoperability in multi-vendor environments.

Designed to reflect networking concepts (Option C):

YANG is specifically designed to reflect networking concepts and constructs, making it intuitive and effective for defining network configurations and states. The hierarchical structure of YANG models aligns well with the structure of network configurations, allowing for precise and clear definitions of network elements and their relationships.

References:

Cisco YANG Overview

IETF YANG

A hybrid cloud solution is best suited for a company that wants to use on-premise infrastructure while also leveraging user self-service and scalability features of the cloud.

Hybrid Cloud:

Definition: A hybrid cloud combines on-premise infrastructure (private cloud) with public cloud services, allowing data and applications to be shared between them.

Scalability: Hybrid cloud allows for the flexibility to scale resources up or down as needed. When demand exceeds the capacity of the on-premise infrastructure, additional resources from the public cloud can be utilized.

Self-Service: Users can provision and manage resources without IT intervention, typically through a self-service portal.

Use Cases: This is ideal for businesses that need to maintain control over certain data and applications while taking advantage of the scalability and cost-efficiency of the public cloud.

Other Cloud Types:

Public Cloud: Fully managed by third-party providers and shared among multiple organizations. It offers high scalability but may have concerns about data privacy and control.

Private Cloud: Exclusively used by one organization, providing more control and security but may be limited in scalability compared to public cloud.

Multi-Cloud: Use of multiple cloud services from different providers, which can be complex to manage but provides flexibility and redundancy.

References:

Cisco Cloud Solutions: Hybrid Cloud Solutions

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)

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 \

-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 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).

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.

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

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.

 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)

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

1 – D, 2 – C, 3 – A, 4 – B

In the Bash shell, the output of a command can be redirected to a file using the > operator. This operator takes the standard output (stdout) of the command and writes it to the specified file.

Option B (devnet > output.txt): This redirects the output of the devnet command to a file named output.txt.

Option A (devnet & output.txt): This is not a valid redirection operator.

Option C (devnet < output.txt): This uses the file output.txt as input to the devnet command, which is not the requirement.

Option D (devnet I output.txt): This is not a valid redirection operator.

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.

Injection attacks occur when untrusted data is sent to an interpreter as part of a command or query. The attacker's hostile data can trick the interpreter into executing unintended commands or accessing data without proper authorization. Common types of injection attacks include SQL injection, command injection, and LDAP injection. These types of attacks exploit vulnerabilities in how an application processes input data, allowing attackers to inject malicious commands or queries into the system.

 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 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.

A default gateway serves as an access point or IP router that a networked computer uses to send information to a computer in another network or the internet. It is essentially the forwarding node that routes traffic from a local network to other networks. When an IP packet's destination is not within the local network and no specific route is defined in the routing table, the packet is sent to the default gateway.

When a REST API limits the amount of data returned in a response, it often uses pagination. Pagination breaks the response into smaller, more manageable chunks, allowing the client to retrieve the data in multiple requests.

Pagination: Limits the number of records returned in a single response, requiring additional requests to retrieve subsequent records.

Payload limit: Restricts the size of the response payload but is not the specific feature for controlling record count.

Rate limiting: Controls the number of requests a client can make in a given time period.

Service timeouts: Define how long the server will wait for a request to complete before timing out.

The YANG structure shown defines a leaf IPPeer that can be either an IPv4 address or an IPv6 address. The third JSON example correctly represents this union type by using an array with both possible types included:

"IPPeer": [

"10.1.1.1",

"2001:db::1"

]

}

This correctly reflects the YANG definition, where IPPeer can be either type specified in the union.

References:

YANG - Data Modeling Language

Cisco YANG Models

The Cisco DevNet Sandbox is a resource provided by Cisco that allows developers to access a variety of Cisco products in a development lab environment. This resource enables users to explore, learn, and build applications using Cisco APIs. The sandbox environment is equipped with pre-configured topologies and a range of Cisco technologies, offering a safe and secure space to experiment without the need for physical hardware.

DevNet Sandbox: Provides access to virtual environments for learning and development.

DevNet Communities: Are for discussions and collaboration among developers.

DevNet Code Exchange: Offers code repositories and examples for various Cisco technologies.

DevNet Automation Exchange: Focuses on automation scripts and tools shared by the community.

To extract the value "172.16.0.11" from the given JSON data, you need to navigate through the JSON structure using the correct keys and indices. The JSON structure provided is as follows:

"items": [{

"kind": "object#NetworkObj",

"selfLink": " ",

"name": "db01",

"host": {

"kind": "IPv4Address",

"value": "172.16.0.11"

},

"objectId": "db01"

}]

}

Access the 'items' key: This gives you a list containing one object.

Access the first object in the 'items' list: Using the index [0].

Access the 'host' key: This contains the 'kind' and 'value' keys.

Access the 'value' key within the 'host' object: This gives you the required value "172.16.0.11".

Thus, the correct way to access the value "172.16.0.11" is data['items'][0]['host']['value'].

References:

JSON Parsing in Python: Python JSON Module

Cisco DevNet Documentation: DevNet JSON Handling

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

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.

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.

In NETCONF, the operation retrieves all or part of a configuration and state data from the running datastore. The operation retrieves configuration data from a specific configuration datastore (e.g., running, startup). These operations correspond to the RESTCONF GET operation, which is used to retrieve configuration and state data from a network device. This mapping between NETCONF and RESTCONF operations is described in detail in the RFC 6241 for NETCONF and RFC 8040 for RESTCONF.

A MAC (Media Access Control) address is a unique identifier assigned to a network interface card (NIC) for communications at the data link layer of a network segment. MAC addresses are used within local area networks (LANs) to ensure that data packets are delivered to the correct hardware device. Every network interface on a device, such as a computer, router, or switch, has a unique MAC address.

Solution below as

Cisco DNA Center provides a REST API that allows users to interact with the network devices managed by the platform. To retrieve a list of network devices, an HTTP GET request is sent to the endpoint . The response from this request contains a list of network devices in JSON format. This API endpoint allows for programmatic access to network device data, facilitating automation and integration with other systems. Detailed information about the Cisco DNA Center APIs can be found in the Cisco DNA Center API documentation.

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Bottom of Form

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.

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.

A version control system (VCS) is essential for managing changes to source code over time. One significant advantage of a VCS is:

Facilitates resolving conflicts when merging code (Option C):

Version control systems like Git track changes made by different developers and provide tools to manage and merge these changes. When multiple developers work on the same codebase, conflicts can arise if they make changes to the same lines of code. A VCS helps in identifying these conflicts and provides mechanisms to resolve them, ensuring that the final merged code is consistent and error-free.

References:

Git Documentation on Merging

Cisco DevNet Version Control Systems

Firewalls are used to control incoming and outgoing network traffic based on predetermined security rules, primarily by limiting traffic to only the necessary ports for an application.

Port Filtering: Firewalls can block or allow traffic based on port numbers, thus limiting exposure to only those ports required by the application, enhancing security.

Security: This helps to protect the application from unauthorized access and potential attacks by reducing the attack surface.

The described behavior, where an automation script fails to connect to an internal server exactly 50% of the time from different clients, suggests an issue with a load balancer. Load balancers distribute incoming network traffic across multiple servers to ensure reliability and performance. If a load balancer is misconfigured or if one of the backend servers is down, the connection might fail intermittently, which aligns with the described 1 out of 2 failure rate.

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

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

Device-level management allows for more granular control over the specific settings and configurations of individual network devices. This is beneficial in scenarios where fine-tuning of device settings is required, and where certain configurations may not be exposed or supported by the overarching controller. Controller-level management, on the other hand, abstracts many device-specific settings to provide a more uniform and simplified management interface, which may not support all the detailed configurations available at the device level.

References:

Cisco DevNet: Device vs. Controller Management

Routers play a crucial role in networking by providing several key functions, including:

Broadcast Domain Segmentation: Routers separate broadcast domains, preventing broadcast traffic from one network segment from spreading to another. This improves network efficiency and reduces unnecessary traffic.

Routing: Routers forward packets between different networks based on IP addresses, enabling communication between devices on different subnets or networks.

Network Address Translation (NAT): Routers can perform NAT, which allows multiple devices on a local network to share a single public IP address.

References:

Cisco DevNet Associate Certification Guide

Cisco Router Functions

A router is a network component that enables communication between different broadcast domains by forwarding data packets between them based on their IP addresses.

Broadcast Domains: A broadcast domain is a network segment where a broadcast frame is forwarded to all devices.

Router Function: Routers separate broadcast domains, allowing communication between them by routing packets based on their destination IP addresses.

References:

Network Components: Routers and Broadcast Domains

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.

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

In the provided Python code, the API_PASSWORD is retrieved from the environment variable API_PASSWORD. To set this environment variable in a Bash shell, the correct command to use is export. This command sets the environment variable for the current shell session and any child processes.

Bash Command: export API_PASSWORD=Cisco123!

This command ensures that the environment variable API_PASSWORD is set to "Cisco123!" and can be accessed by the Python script.

References:

Bash export Command

Cisco DevNet Associate Certification Guide

The exhibit shows an XML configuration using NETCONF (Network Configuration Protocol) to edit the configuration of a network device. Specifically, the operation is being used with the nc:operation="delete" attribute within the element. This means that the configuration is intended to delete specific configurations related to the interface named FastEthernet0/0/3.9.

Here is the detailed explanation:

The element initiates a remote procedure call.

The element specifies the operation to be performed.

The element with indicates that the changes are to be made to the running configuration.

The element contains the configuration data to be applied.

Within , the element with nc:operation="delete" specifies that the interface configuration for FastEthernet0/0/3.9 is to be deleted.

This configuration does not affect all device configurations or shut down the device but deletes the specified interface configuration.

References:

Cisco DevNet Associate Certification Guide

RFC 6241 - Network Configuration Protocol (NETCONF)

from ucsmsdk.ucshandle import UcsHandle

connection = UcsHandle("10.10.20.113", "ucspe", "ucspe")

connection.login()

orgs = []

ucsm_orgs = connection.query_classid("orgOrg")

for org in ucsm_orgs:

temp_org = {"name": org.name, "dn": org.dn, "rn": org.rn}

orgs.append(temp_org)

print(orgs)

Understanding the UCSHandle Class:

Purpose: The UcsHandle class is used to interface with the UCS Manager.

Parameters: It requires parameters like IP address, username, password, port, secure, and proxy.

Python Script Explanation:

Importing UcsHandle: The first step is to import the UcsHandle class from the ucsmsdk.ucshandle module.

Creating a Connection: An instance of UcsHandle is created with the UCS Manager's IP address, username, and password.

Login: The login() method is called on the UcsHandle instance to establish a session with the UCS Manager.

Querying Organizations: The query_classid() method is used to retrieve objects of a specific class, in this case, "orgOrg" which represents organizations.

Looping through Results: The script iterates over the retrieved organizations, extracting their name, distinguished name (dn), and relative name (rn), and appending this information to the orgs list.

Printing Results: Finally, the orgs list is printed, which contains the details of all the organizations.

References:

Cisco DevNet Associate Certification Guide, Sections on UCS Manager API and Python SDK

UCS Python SDK Documentation

To protect secrets such as API URLs, shared keys, and other application configurations, it is best practice to: C. Ensure they never appear in plaintext at rest or in transit. Encrypt sensitive data both when it is stored (at rest) and when it is transmitted over the network (in transit). This prevents unauthorized access and exposure. E. Always store secrets in a secure vault. Use dedicated secret management tools like HashiCorp Vault, AWS Secrets Manager, or Azure Key Vault to store and manage sensitive information securely. These tools provide mechanisms for access control, audit logging, and automatic rotation of secrets.

References:

Securing Secrets

HashiCorp Vault

AWS Secrets Manager

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

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.

When using OAuth2 authentication for accessing a protected resource via a REST API, the typical flow involves obtaining an access token which can then be used to authenticate subsequent API requests. The correct process is:

POST Call to /login: Make a POST request to the /login endpoint with the user credentials (username and password) in the request body. This call will authenticate the user and, if successful, return an access token.

Use the Token: Use the retrieved token by including it in the Authorization header (usually as a Bearer token) in the request to access the protected resource, in this case, the /item endpoint.

References:

OAuth 2.0 Authorization Framework - RFC 6749

The git merge-file command is used to merge changes from a specified file into the working directory file. This is particularly useful when you have a separate file with bug fixes and you need to incorporate those fixes into your production code. The command takes three files: the base file, the current file, and the file with changes. It then merges the changes into the current file.

Example usage:

bash

Copy code

git merge-file

References:

Git Documentation - git merge-file

Cisco DevNet Associate Certification Guide

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

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.

In the given Dockerfile, the WORKDIR /app command sets the working directory for any subsequent commands to /app. This means that any commands following this line will be executed within the /app directory inside the Docker container. The COPY . . command copies the contents of the current directory on the host machine to the /app directory in the container. Finally, the CMD ["node", "source/server.js"] command specifies the command to run when the container starts, which in this case is node source/server.js.

References:

Dockerfile Reference - WORKDIR

HTTP status codes in the 300 range are related to redirection. These codes indicate that the requested resource has been moved to a different URL, and the client should use the new URL provided in the response. Common examples include 301 (Moved Permanently) and 302 (Found).

NETCONF (Network Configuration Protocol) operates over TCP port 830. It is a protocol defined for managing network devices and configurations. NETCONF provides mechanisms to install, manipulate, and delete the configuration of network devices. It uses XML as its data encoding format and allows for easy automation of network configuration tasks.

References:

Cisco DevNet Associate Certification Guide

RFC 6241 - Network Configuration Protocol (NETCONF)

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

In Ansible, when using the netconf_config module to automate configuration tasks that include unique interface variables for each device, the variables should be defined in individual YAML files within the host_vars directory. This directory contains host-specific variable files named after each host, allowing Ansible to load the appropriate variables for each device during playbook execution.

References:

Ansible Documentation - Variable precedence

Cisco DevNet Associate Certification Guide

RESTCONF is a protocol used for accessing data defined in YANG, using RESTful principles. It is suitable for retrieving configuration data in JSON format from a Cisco CSR 1000 V instance. RESTCONF allows network devices to be managed using HTTP methods, and it supports both XML and JSON as data formats, making it ideal for outputting device configurations in JSON.

HTTP status code 429 indicates that too many requests have been sent in a given amount of time, which is a sign of rate limiting. Rate limiting is used by APIs to control the amount of incoming requests to prevent abuse or overloading the server. In this case, the Cisco Prime API is limiting the number of requests the network engineer can make in a certain time period, resulting in only a subset of devices being returned and some requests being rejected with a 429 status code.

References:

Cisco DevNet Associate Certification Guide

HTTP Status Code Definitions

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 main security issue in this scenario is the transmission of credentials in cleartext over HTTPS. Even though HTTPS provides a secure transport layer, the credentials should still be protected, such as by using secrets or encryption. Additionally, setting logging to debug and potentially exposing these credentials in logs is also a security concern.

Cleartext Credentials: Sending credentials in cleartext within the webhook payload can expose them if HTTPS is not configured correctly or if intercepted by an attacker.

Debug Logging: Enabling debug logging can expose sensitive information, including credentials, in logs.

Option B highlights the risk of transmitting credentials unencrypted over HTTPS, which can lead to credential leakage.

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.

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.

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.

Agile:

Optimization of the development process

Focused on the processes of a specific team

Lean:

Optimization of the production process

Focused on the processes of an organization

Agile Methodology:

Optimization of the Development Process: Agile focuses on improving and optimizing the software development process through iterative and incremental development, continuous feedback, and adapting to changes quickly.

Focused on the Processes of a Specific Team: Agile practices are typically implemented within specific development teams, emphasizing collaboration, flexibility, and team autonomy.

Lean Methodology:

Optimization of the Production Process: Lean aims to streamline the production process by eliminating waste, improving efficiency, and delivering value to the customer with the least amount of resources.

Focused on the Processes of an Organization: Lean principles can be applied across the entire organization, not just within individual teams, to improve overall processes and workflow efficiency.

References:

Cisco DevNet Associate Certification Guide, Sections on Agile and Lean methodologies

Official documentation and resources on Agile and Lean software development practices

"The Lean Startup" by Eric Ries (for Lean principles)

"Agile Software Development with Scrum" by Ken Schwaber and Mike Beedle (for Agile principles)

Therefore, the correct mapping is:

Agile:

Optimization of the development process

Focused on the processes of a specific team

Lean:

Optimization of the production process

Focused on the processes of an organization

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 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

Before running an Ansible playbook to configure Cisco Nexus devices using the NX REST API, it's important to verify that the REST API requests work as expected. The best resource for this purpose is Cisco Open NX-OS, which provides detailed information and tools for working with the NX-OS REST API.

Cisco Open NX-OS: This platform provides extensive documentation, tools, and examples for using the NX-OS REST API. It is an ideal resource for testing and validating REST API requests before automation.

Other Resources:

Cisco NX-OS SDK: Provides software development tools for NX-OS but is less focused on REST API verification.

Cisco Learning Labs: Offers hands-on labs for learning, but not specifically for REST API testing.

Cisco Code Exchange for Nexus: Provides code examples, but not specifically for testing REST API requests.

References:

Cisco DevNet Associate Certification Guide

Cisco Open NX-OS

Top of Form

Bottom of Form

Version control systems (VCS) are essential for managing changes to code and files in a project. They track all modifications, enabling multiple users to work collaboratively while maintaining a history of changes.

Tracking Changes: VCS keeps a detailed history of changes made to files, including who made the change and when.

Collaboration: Multiple users can work on the same project simultaneously without overwriting each other's work.

Reverting Changes: It allows reverting to previous versions if a mistake is made.

Option B is correct as it highlights the primary benefit of version control—keeping track of all changes to the files.

The Ansible playbook in the exhibit consists of two stages:

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

Stage 2: Starts the httpd service.

Stage 1:

- name: stage1

ansible.builtin.service:

name: network

state: restarted

args: eth0

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

Stage 2:

- name: stage2

ansible.builtin.service:

name: httpd

state: started

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

References:

Ansible Playbook Documentation: Ansible Service Module

An HTTP 404 status code indicates that the requested resource could not be found. In the context of the Cisco DNA Center API, this usually means that the URL being accessed is incorrect or the endpoint does not exist. The solution is to verify and correct the API URL to ensure it points to a valid endpoint.

Example correct API URL:

url = ' '

This ensures that the script is making requests to the correct API endpoint.

References:

Cisco DNA Center API Documentation

Cisco DevNet Associate Certification Guide