JN0-223 Automation and DevOps Associate (JNCIA-DevOps) Questions and Answers

QUESTION NO: 64

Which statement is correct about Ansible playbooks?

A. A playbook is a configuration file that defines the Ansible related parameters

B. A playbook contains one or more tasks written in XML

C. A playbook can contain multiple tasks and execute multiple Python modules

D. A playbook is a specific Python module that is executed on a host

Answer:C

When using the REST API on a Junos device, theisrpd(Integrated Service Routing Process Daemon) process is responsible for handling REST API requests. This process listens for incoming HTTP requests and processes them accordingly, including retrieving interface configuration information when a GET request is made.

Option Bis correct because theisrpdprocess handles the REST API requests on a Junos device.

Options A (mod process), C (rpd process), and D (isd process)are incorrect in this context as they either do not exist or serve different purposes on a Junos device.

Supporting References:

Juniper Networks REST API Documentation:Provides insights into how REST API requests are managed and processed by theisrpdprocess on Junos devices.

The NETCONF protocol, used for network management, utilizes XML for encoding the RPC (Remote Procedure Call) requests and responses. XML is chosen because of its flexibility and ability to represent hierarchical data structures, making it well-suited for representing network configurations and states.

Option Bis correct because XML is the standard format used for NETCONF RPC payloads.

Options A (YAML), C (JSON), and D (HTML)are incorrect because these formats are not used by NETCONF for its RPC payloads.

Supporting References:

RFC 6241 - NETCONF Protocol:This RFC describes the use of XML for encoding NETCONF messages.

DevOps is a set of practices, tools, and cultural philosophies that aims to integrate and automate the processes between software development and IT operations teams. The primary goal of DevOps is to shorten the systems development life cycle and provide continuous delivery with high software quality.

Option C is correct because DevOps fundamentally focuses on breaking down the silos between development and operations teams, fostering a collaborative environment where these teams work together throughout the entire software lifecycle. This collaboration extends to other stakeholders, including quality assurance (QA), security, and more, to ensure that the product is continuously delivered and improved based on real-time feedback.

DevOps promotes a cultural shift where teams are no longer isolated but work together to share responsibilities, which leads to increased efficiency, faster problem resolution, and a more streamlined deployment process. This culture of collaboration is supported by various automation tools and practices such as Continuous Integration (CI), Continuous Deployment (CD), Infrastructure as Code (IaC), and automated testing.

Supporting References:

Juniper Networks Automation and DevOps Documentation:This documentation emphasizes the importance of collaboration between development and operations teams to streamline processes and improve efficiency, aligning perfectly with the principles of DevOps.

"The DevOps Handbook"by Gene Kim, Patrick Debois, John Willis, and Jez Humble: This book provides an in-depth look into how DevOps practices enhance collaboration and lead to faster, more reliable software delivery.

IEEE and Industry Standards:While DevOps practices are widely adopted, they are not defined or maintained by IEEE or any other formal standards body, which is why option D is incorrect.

In Junos, theJET (Junos Extension Toolkit)API supports direct modification of theEphemeral database. The Ephemeral database is a temporary configuration database used in Junos OS, allowing for changes that do not persist after a reboot unless explicitly committed to the permanent configuration.

JET API: Allows for high-performance interactions with Junos, including the ability to make changes to the Ephemeral database, which is useful for temporary configurations, dynamic policies, and other operational tasks.

Other options like WebSocket, SOAP, and REST do not provide direct access to the Ephemeral database in Junos.

Juniper Networks JET Documentation: Details how JET API interacts with the Ephemeral database.

Junos Automation and DevOps Documentation: Discusses the use of JET for automation and dynamic configuration.

References:

Both YAML and JSON are case-sensitive, meaning that the distinction between uppercase and lowercase characters matters. For example, in JSON or YAML,Keyandkeywould be considered different.

Option D (case-sensitive)is correct because both YAML and JSON treat keys and values with different cases as distinct.

Option Ais incorrect because, while JSON does not use indentation, YAML does rely on indentation to define structure.Option Bis incorrect because whitespace can be significant in YAML for structure, andOption Cis incorrect because JSON does not support comments, while YAML does.

Supporting References:

YAML and JSON Documentation:The official specifications for both YAML and JSON emphasize their case sensitivity.

NETCONF (Network Configuration Protocol) is used for network device management and can operate over SSH. The following are true about NETCONF:

Default Port 830 (B): By default, NETCONF uses port 830 for communication over SSH. This is the standard port reserved for NETCONF sessions.

Use of Default SSH Port (D): NETCONF can also operate over the standard SSH port (port 22) if configured to do so. This allows flexibility in network management scenarios where port 830 might not be available or used.

Options A and C are incorrectbecause they refer to incorrect or non-applicable port numbers for NETCONF.

IETF RFC 6241: Specifies the use of NETCONF over SSH, including port details.

Juniper Networks NETCONF Documentation: Discusses the configuration and operation of NETCONF on Junos devices, including port usage.

References:

In Junos OS, acommit scriptis an on-box automation script that runs every time a configuration change is committed. Commit scripts are used to enforce configuration policies, validate configuration changes, or make automatic adjustments to configurations when certain conditions are met.

Commit Script (C): Executes automatically during the commit process, ensuring that the new configuration adheres to specific rules or conventions before it is applied to the system.

Event, SNMP, and operation scriptsare used for other purposes in Junos automation but do not run automatically with every configuration change.

Junos OS Automation Scripts Guide: Provides details on different types of scripts, including commit scripts, and their use cases.

Juniper Networks Documentation: Offers examples and best practices for creating and using commit scripts.

References:

Juniper Networks' Junos operating system supports several APIs for on-box scripting, two of which are:

JET (Juniper Extension Toolkit): JET is a modern API framework that provides a programmable interface for interacting with Junos. It allows developers to create custom applications that run directly on Junos devices, enabling the automation of network operations. JET provides both a gRPC and a REST API interface, allowing for flexible integration with external systems.

XML API: The Junos XML API allows direct interaction with the Junos OS through XML-based requests. This API can be used to retrieve information, configure devices, and execute commands on Junos devices. The XML API is crucial for automation tasks as it provides a structured and consistent way to interact with the device's configuration and operational data.

JET (A)provides high-performance access to Junos routing, switching, and service elements via programmable interfaces. It is highly used for creating custom applications that require tight integration with the Junos OS.

XML (C), on the other hand, is a well-established method for interacting with Junos, especially for legacy systems or when working within environments where XML is the standard data format.

Detailed Explanation:Other options like Puppet (B) and Chef (D) are not APIs provided by Junos for on-box scripting but are configuration management tools used externally to manage Junos devices.

Juniper Networks JET Documentation: Provides details on how to leverage JET APIs for automation.

Junos XML Management Protocol Guide: Describes how to use XML for scripting and automating tasks in Junos.

References:These APIs are key components of Juniper's automation strategy, allowing for scalable, flexible, and efficient network operations.

NETCONF (Network Configuration Protocol) operates through different layers, with the operations layer being particularly important for managing configurations:

Operations Layer (A & D): This layer is responsible for actions like locking and committing the configuration on a Junos device. The lock operation prevents other sessions from modifying the configuration, and the commit operation applies the configuration changes to the device.

Options B and Care incorrect because the messages layer handles the communication aspects, such as exchanging data between the client and server, not performing configuration operations like locking and committing.

IETF RFC 6241 (NETCONF): Describes the protocol layers and their functions, with a focus on the operations layer.

Juniper Networks NETCONF Documentation: Provides insights into how NETCONF operations are managed in Junos

References:

REST (Representational State Transfer) is an architectural style for designing networked applications, and its key principles include:

Statelessness (B): Each request from the client to the server must contain all the information needed to understand and process the request. The server does not store any session state between requests, meaning each request is independent and does not rely on previous ones.

TCP Session State (C): While REST itself is stateless, the underlying TCP connection's state, such as keeping the connection alive or managing retries, is handled by the client. The server does not retain information about the TCP connection beyond the processing of the individual request.

Options A and D are incorrect because they imply that the REST API is stateful, which contradicts the stateless nature of REST.

REST API Design Principles: Describes the stateless nature of REST and the responsibility of clients in managing session state.

Web Development Documentation: Discusses how REST APIs operate, focusing on statelessness and client-server interaction.

References:

In JSON (JavaScript Object Notation), the two primary data structures are:

Objects:These are collections of key-value pairs, where each key is a string, and the value can be a string, number, array, boolean, or another object. In Python, this structure is analogous to a dictionary.

Arrays:These are ordered lists of values, where each value can be of any data type, including another array or object. In Python, this structure is similar to a list.

Option A (tuples)andOption D (dictionaries)refer to Python-specific data structures and are not directly used in JSON.

Supporting References:

JSON Documentation and Tutorials:JSON objects and arrays are the standard data structures used in this format, as described in many tutorials and the official JSON documentation.

When using theset rest control configurationcommand on a Junos device, you have several options to control access to the REST API. Two effective methods include:

Limiting the number of simultaneous connections:This ensures that the REST API is not overwhelmed by too many concurrent requests, which could potentially lead to performance issues or denial of service.

Limiting access to certain source IP addresses:This method restricts API access to specific IP addresses, enhancing security by ensuring that only trusted sources can interact with the REST API.

Option A (Limit management access to only SSH)is unrelated to controlling REST API access specifically.

Option B (Limit management access to specific users)might be relevant in a different context, but it is not directly tied to REST API control via the specific command mentioned.

Supporting References:

Juniper Networks REST API Documentation:This documentation explains how to configure and control access to the REST API on Junos devices, including connection limits and IP-based access control.