The playbook uses Variables and Loops to push configuration commands.

1. Variables (vars): In the dna_servers list, the first item is missing its value. To match the second entry (208.67.220.220), you must provide an IP address. The only valid IP address in the options is 208.67.222.222.
2. Loops (with_items): The with_items statement tells Ansible which list to iterate over. To access the list defined in the vars section, you must reference the variable name dns_servers. Note that "dna_servers" in the image appears to be a slight typographical variation of the intended variable name "dns_servers," which is the standard term for these objects in Ansible networking logic.

The ios_config module then takes each {{ item }} and executes it as a command on the target IOS device.

Official Vendor Documentation: Cisco DevNet, "Introduction to Ansible for Cisco Network Engineers." Section: Defining Variables and Lists.

Official Vendor Documentation: Ansible Documentation, "ios_config – Manage Cisco IOS configuration sections." (Reference for lines and with_items interaction).

Official Vendor Documentation: Ansible Documentation, "Playbook Variables." Section: Defining Variables in a Play.

University Courseware: University of Colorado Boulder, "Network Automation and Programmability." Module: Ansible Playbook Structure and Syntax.

To create a new resource in the Cisco FDM API, a POST request is sent to the collection endpoint. The endpoint for network-related objects (including hosts, ranges, and subnets) is /object/networks. Within the JSON payload, the "type" attribute for these entities must be defined as "networkobject", while the specific nature of the object (Host) is defined by the subType. For authentication, Cisco FDM utilizes token-based security, requiring the "Bearer" prefix in the Authorization header. The option f'{BASE_URL}/object/hosts/{ID}' is incorrect for creation as it is a specific resource URI used for GET, PUT, or DELETE operations on an existing object ID.

Cisco DevNet: Firepower Device Manager REST API Guide. Section: "Working with Network Objects."

Details: Specifies the POST method to /object/networks for creating new host objects.

Cisco Firepower Threat Defense (FTD) API Explorer (Built-in Documentation). Endpoint: POST /object/networks.

Details: Defines the schema where 'type' must be 'networkobject' and 'subType' can be 'HOST', 'NETWORK', or 'RANGE'.

Cisco FDM API Authentication Overview. Section: "Token-Based Authentication."

Details: Confirms the use of HTTP Authorization header with the 'Bearer' scheme for API calls following the initial login.

RFC 6750: The OAuth 2.0 Authorization Framework: Bearer Token Usage.

Details: Standardizes the Authorization: Bearer format used by modern REST APIs like Cisco FDM.

To complete the CI/CD pipeline, the built Docker image must be uploaded to the GitLab Container Registry so that subsequent stages can access it. In the build_container stage, the script builds an image and runs a container, but these actions only occur locally on the GitLab Runner. The second stage, get_config, specifies image: registry.gitlab.com/$DOCKER_USERNAME/$DOCKER_REPOSITORY. For the runner to pull this image in the next stage, the image must first be pushed to the remote registry. The docker push command is the standard Docker CLI instruction used to share local images with a registry. Without this step, the second stage would fail to locate the updated image.

Option A is incorrect because docker assign is not a valid Docker CLI command. To associate a name with an image, docker tag or docker commit is used instead.

Option B is incorrect because docker info is a diagnostic command used to display system-wide information regarding the Docker installation. It does not perform image uploads.

Option C is incorrect because docker logout terminates the authenticated session with the registry. Executing this before pushing would prevent the image from being uploaded, causing the pipeline to fail.

GitLab Official Documentation: GitLab CI/CD - Use Docker to build images. This section details the requirement to push images to the registry using docker push so they can be used in later stages.

Docker Documentation: Docker CLI Reference - docker push. Describes the syntax and purpose of uploading images to a registry.

Cisco DevNet Associate (DEVASC) 200-901 Official Cert Guide: Chapter 16, "Application Deployment and Security," covers the workflow of building, pushing, and pulling images within a CI/CD pipeline.

GitLab Official Documentation: Container Registry - Authenticate with the Container Registry. Explains the lifecycle of login, build, push, and logout within .gitlab-ci.yml.

In RESTful API interactions, specifically when using a POST method to create a resource (such as adding a static route in Cisco Meraki), the standard HTTP success status code is 201 Created. The first box must initiate a conditional check for this specific success code to trigger the print("Done!") statement. The second box requires the else: keyword to provide a fallback execution path; if the response code is anything other than 201 (indicating a client or server error), the script will execute the indented block to print the failure message and the associated error text from the response.

Cisco Meraki Developer Portal: API Reference for "Create a Network Static Route." It explicitly states that a successful request returns an HTTP Status 201.

RFC 9110 (HTTP Semantics), Section 15.3.2: Defines the 201 Created status code as the standard response indicating that the request has been fulfilled and has resulted in one or more new resources being created.

Python Software Foundation (Python 3.x Documentation): Section 4.1 "The if Statement." Outlines the syntax for if...else control flow structures used for conditional execution.

Cisco Press - DevNet Associate DEVASC 200-901 Official Cert Guide: Chapter covering "Cisco Meraki APIs," which illustrates handling API responses and status code verification in Python scripts.

To query a specific profile, the API requires the profileName query parameter as shown in the API reference (Image 2). The JSON response is a list, so [0] accesses the first profile object. The path starts with the profileDetails key, which contains ssidDetails (a list of SSIDs). To access the first SSID's configuration, the index 0 is used. Within that object, the flexConnect key holds the nested enableFlexConnect property. Correctly mapping these keys ensures the script accurately parses the "ChicagoCampus" profile to determine if FlexConnect is enabled.

Cisco DevNet: Cisco DNA Center Intent API Reference, "Get Wireless Profile" section. URL: https://developer.cisco.com/docs/dna-center/ (API Version 2.3.x).

Details: Confirms profileName as the query parameter and defines the structure of the 200 OK response body.

Cisco Systems: Cisco Digital Network Architecture (DNA) Center Administrator Guide, Release 2.3.5.

Section: "Wireless Profile Settings and API Integration."

Cisco Learning Network: Implementing and Operating Cisco Enterprise Network Core Technologies (ENCOR) 350-401 Official Cert Guide.

Chapter: "Automation and Programmability - Cisco DNA Center APIs."

Cisco DevNet Learning Labs: "Parsing JSON responses from Cisco DNA Center with Python."

Topic: Navigating nested dictionaries and lists in Intent API responses.

AppDynamics End User Monitoring (EUM) provides visibility into application performance from the client's perspective. This includes Browser Real User Monitoring (RUM), Mobile RUM, and IoT Monitoring. A core capability of Mobile and IoT RUM is to capture and analyze network requests made from the end-user's device. This allows operations teams to identify and troubleshoot the slowest network requests, crashes, and other errors, thereby locating the root cause of performance problems experienced by the user on their specific device.

A. This describes the function of AppDynamics Network Visibility, which focuses on monitoring the network transport layer and its impact on application performance, not the client-side experience itself.

B. This is a capability of AppDynamics Server Visibility (or Infrastructure Visibility), which monitors the health and performance of servers, including CPU, memory, and running processes.

D. This is the primary function of AppDynamics Database Visibility, which provides deep insights into database performance, including slow queries and resource contention within the database tier.

1. AppDynamics Documentation

"End User Monitoring": "End User Monitoring (EUM) gives you a view of your application's performance from the perspective of the end user... Mobile RUM helps you understand the cause of crashes

errors

and slow network requests." (Source: AppDynamics Official Documentation

Product Documentation section on End User Monitoring).

2. AppDynamics Documentation

"Mobile RUM": "With Mobile RUM

you can: Identify and troubleshoot slow network requests

crashes

and other errors." (Source: AppDynamics Official Documentation

"Get Started with Mobile RUM" section).

3. AppDynamics Documentation

"Network Visibility": "Network Visibility provides a dynamic topology map of traffic flows

nodes

and transport connections where network or application/network issues are developing." (Source: AppDynamics Official Documentation

"Network Visibility" section).

4. AppDynamics Documentation

"Server Visibility": "Server Visibility provides an extensive set of metrics that monitor local processes

services

and resource use to explain problematic server performance." (Source: AppDynamics Official Documentation

"Server Visibility" section).

5. AppDynamics Documentation

"Database Visibility": "Database Visibility provides metrics on the performance of the database to troubleshoot performance-related issues." (Source: AppDynamics Official Documentation

"Database Visibility" section).

The git reset HEAD command is the standard and correct way to unstage a file in Git. When a file is accidentally staged using git add, this command removes it from the staging area (index) without modifying the file in the working directory. It essentially resets the state of the specified file in the index to match what is in the HEAD commit, effectively "unstaging" it. This allows the developer to proceed with a clean commit that includes only the intended files.

A. git delete is not a valid Git command for this purpose.

B. git remove is not a valid Git command. The correct command is git rm, which removes files from both the staging area and the working directory.

D. git revert is used to create a new commit that undoes the changes of a previous commit; it does not operate on the staging area for unstaging files.

1. Chacon

S.

& Straub

B. (2014). Pro Git (2nd ed.). Apress. In Chapter 2

"Git Basics

" Section 2.2

"Recording Changes to the Repository

" under the subsection "Unstaging a Staged File

" the text explicitly states: "As it turns out

git reset HEAD ... does the trick."

2. Official Git Documentation. (n.d.). git-reset. git-scm.com. Retrieved from https://git-scm.com/docs/git-reset. The documentation specifies: "When is given

git reset updates the index (i.e. sets it to the tree of ) for the given paths... (It does not affect the working tree...)"

3. MIT Missing Semester of Your CS Education. (2020). Lecture 6: Version Control (Git). In the "Staging area" section

the lecture notes demonstrate that git reset is the command used to unstage a file. Retrieved from https://missing.csail.mit.edu/2020/version-control/

The best practice for separating application configuration from code, as advocated by the Twelve-Factor App methodology, is to store it in environment variables. This approach ensures a clean decoupling of the application from its deployment environment. Configuration stored in the environment can be easily changed between deployments without any code modifications. This method enhances portability, as the same application artifact (e.g., a container image) can be promoted through different environments (development, staging, production) by simply setting the appropriate environment variables at runtime. It also improves security by preventing sensitive credentials from being committed to a code repository.

B. YAML files: While common, config files can be accidentally committed to version control and often lead to environment-specific files, which is a less clean separation than environment variables.

C. Python libraries: Storing configuration in a library is a form of hardcoding, directly violating the principle of separating configuration from the application code.

D. Dockerfiles: Baking configuration into a Dockerfile creates an inflexible container image that is tied to a specific environment, preventing the reuse of the same image across different stages.

E. INI files: Similar to YAML files, INI files are a file-based configuration method that is considered inferior to environment variables for modern, cloud-native applications.

1. The Twelve-Factor App

III. Config: "The twelve-factor app stores config in environment variables... Unlike config files

they are a language- and OS-agnostic standard. Another aspect of config management is grouping. Sometimes apps group config into named groups... A twelve-factor app is opposed to this grouping of configs

and instead encourages tools to manage these values separately for each deploy."

Source: Heroku

"The Twelve-Factor App

" Section III. Config. Retrieved from https://12factor.net/config

2. Kubernetes Documentation

Configure a Pod to Use a ConfigMap: "A common usage pattern is to set environment variables for a Pod using data from a ConfigMap... This makes your application configuration portable." This official documentation for a core container orchestration platform demonstrates the implementation of the environment variable pattern.

Source: Kubernetes Authors

"Configure a Pod to Use a ConfigMap

" Kubernetes Documentation

spec.containers[].envFrom and spec.containers[].env sections.

3. Docker Documentation

Docker run reference: "With the -e

--env

and --env-file flags

you can set environment variables for the process running inside the container... This allows you to run the same image in development

test

and production with different configurations."

Source: Docker Inc.

"Docker run reference

" Docker Docs

Environment variables (-e

--env

--env-file) section.

The provided YAML defines a StatefulSet, which requires a specific structural hierarchy.

1. kind: In Kubernetes manifests, the top-level field that defines the object type (e.g., Pod, Service, StatefulSet) is kind.
2. spec: Following metadata, the spec field is mandatory to define the desired state of the resource, including selectors and templates.
3. image: Inside the container definition, the image key specifies the registry path (repo.cisco.com/...) for the Docker container.
4. containerPort: Under the ports list, containerPort is the correct field to expose the port (8888) where the application is listening inside the container.

Kubernetes Official Documentation: "Understanding Kubernetes Objects," Section: Required Fields (apiVersion, kind, metadata, spec). Link

Kubernetes API Reference v1.25: "StatefulSetSpec" and "Container" definitions for specifying images and ports. Link

Cisco DevNet Learning Labs: "Introduction to Kubernetes for Cisco Developers," module on YAML syntax and containerized deployment.

CNCF (Cloud Native Computing Foundation): Kubernetes Certified Application Developer (CKAD) curriculum, Topic: Core Concepts and Pod Configuration.

To create a valid Dockerfile, the instructions must follow a specific logical order:

1. FROM: Every Dockerfile must start with a base image (e.g., python:3.6-alpine).
2. EXPOSE: Since the application is hosted as a web application accessible remotely, it needs to inform Docker that the container listens on port 8080 at runtime.
3. ENTRYPOINT & CMD: When used together in "exec form," ENTRYPOINT defines the main command (python3), while CMD acts as the default flags or arguments (-m, server). This allows the container to run as an executable. EXEC and PORT are not valid Dockerfile instructions.

Docker Documentation: Dockerfile reference - FROM. Defines the initial stage and sets the Base Image for subsequent instructions.

Docker Documentation: Dockerfile reference - EXPOSE. Explains how the instruction functions as documentation between the image developer and the person running the container regarding which ports are intended to be published.

Docker Documentation: Dockerfile reference - ENTRYPOINT vs CMD. Detailed breakdown of how ENTRYPOINT sets the executable and CMD provides default arguments that can be overridden.

Open Container Initiative (OCI): Runtime Specification. Standards regarding how container engines execute commands and handle entrypoints within isolated environments.