JN0-223 Exam Dumps - Automation and DevOps Associate (JNCIA-DevOps)

XPath is a query language used for selecting nodes from an XML document. It supports various logical operators that can be used to create complex queries. The two standard logical operators supported by XPath are:

NOT:This operator negates a condition, returningtrueif the condition is false, and vice versa.

AND:This operator is used to combine two conditions, and it returnstrueonly if both conditions are true.

Option A (IOR)andOption D (MAMD)are not standard XPath operators.

Supporting References:

XPath Documentation:The W3C XPath specification lists the standard operators supported in XPath, includingANDandNOT.

XML Schema Definition (XSD) files are used to define the structure and data types of an XML document. They ensure that the XML document adheres to a specific structure by defining the allowed elements, attributes, and their data types, thereby enforcing a consistent format.

Option Ais correct because XSD files define the elements, attributes, and structure (hierarchy) of an XML document.

Option Dis correct because XSD files provide a standardized format, ensuring that all parties working with the XML document use the same set of tags and structure.

Option B (Every XML document must have an XSD file defined for it)is incorrect; not every XML document requires an XSD file, although it's beneficial for validation.

Option C (An XSD file is not an XML document)is incorrect because XSD files themselves are written in XML.

Supporting References:

W3C XML Schema Definition (XSD) Documentation:Explains the purpose and structure of XSD files, including their role in defining XML document schemas.

In Python, the==operator is used to test whether two variables are equal. It returnsTrueif the variables are equal andFalseif they are not.

Option B (==)is correct because it is the equality operator in Python.

Option A (!=)is used for inequality,Option C (%)is the modulus operator, andOption D (=)is used for assignment, not for testing equality.

Supporting References:

Python Documentation on Operators:The official Python documentation covers the use of==for equality checks.

A. The Junos REST API client is on-box:The Junos REST API ison-box, meaning it is hosted directly on the Junos OS device. This allows you to interact with the device through RESTful API calls without needing an external client to act as an intermediary. With the on-box REST API, users can manage and automate configuration and operational tasks directly from the Junos device itself using HTTP/HTTPS protocols. This simplifies automation and remote management since the API server is embedded within the device.

Key Automation Capabilities of On-box REST API:

Supports configuration, monitoring, and operational commands.

Allows for direct device interaction via tools like curl, or through custom-built automation scripts.

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.

An XML schema document (XSD) is a key component in defining the structure and constraints of XML data used in various applications, including Junos:

Authoritative Source (C): An XML schema document serves as the authoritative definition of the structure, content, and semantics of XML documents. It ensures that the XML data adheres to specific rules and formats, which is essential for both operational and configuration XML.

XSD Format (D): XML schema documents are typically written in the XSD (XML Schema Definition) format, which provides a formal description of the XML document's structure.

Option A is incorrectbecause XML schemas are not formatted as XLT files (which are related to XSLT transformations), andOption B is incorrectbecause XML schemas can indeed be examined in the Junos CLI using appropriate commands.

W3C XML Schema Definition Language (XSD) Documentation: Provides comprehensive information on the XSD format.

Juniper Networks Documentation: Discusses the role of XML schemas in managing Junos configurations.

References:

Aneventscript is used to automate responses to system events in Junos, such as an interface going down. These scripts are triggered automatically when a specified event occurs, making them suitable for tasks like monitoring interface status and executing actions when the status changes.

Option B (event)is correct because event scripts are designed for reacting to system events like an interface going down.

Option A (commit)is used for configuration changes,Option C (operation)is used for operational tasks, andOption D (SNMP)is not applicable in this context.

Supporting References:

Juniper Networks Event Scripts Documentation:Details how event scripts are used to automate responses to specific system events in Junos

In Junos PyEZ, theConfigobject provides various methods for interacting with device configurations. Two of the key methods are:

lock():This method locks the candidate configuration database to prevent other users or processes from making changes while you are modifying the configuration.

config():This method is used to create aConfigobject that represents the configuration database, allowing you to load, modify, and commit configuration changes.

Option C (lock)andOption D (config)are correct because they are valid methods provided by the PyEZConfigobject.

Option A (commie)andOption B (device)are incorrect as they are not methods of theConfigobject.

Supporting References:

Junos PyEZ Documentation:Details the methods available in theConfigobject, includinglock()andconfig().

Junos automation relies on several key processes to handle various automation and API interactions. Let's break down the two key processes involved:

jsd (Junos Script Daemon):The jsd process is responsible for handling automation scripts, including Python and SLAX scripts, as well as handling JET (Junos Extension Toolkit) API requests. This process is fundamental in the automation framework of Junos, as it deals with external and internal API requests, ensuring that the necessary scripts are executed when specific triggers or events occur.

kmd (Key Management Daemon):The kmd process is involved in key management for IPsec and other security services. While its primary function is related to managing cryptographic keys, it plays a role in Junos automation by enabling secure communication and ensuring that automation tasks involving security services (such as automated IPsec tunnel creation) are handled securely.

Why the Other Options Are Incorrect:

A. mod:This process doesn't exist as part of the Junos automation framework. It's likely a distractor.

C. ifd:The ifd process is associated with the physical interfaces on the device and does not play a role in automation or script processing.

References from Juniper Documentation:

Junos Automation Processes

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:

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:

https://www.w3schools.com/xml/xpath_syntax.asp

When using a Python context manager with Junos PyEZ, two key methods are automatically included:

open()andclose(): These methods are used to establish and terminate a connection to a Junos device. When you use a context manager (thewithstatement),open()is called when entering the block, andclose()is called when exiting, ensuring the connection is properly managed.

lock()andunlock(): These methods are used to lock the configuration database to prevent other users from making changes while you are working on it. When using a context manager,lock()is called at the start of the block, andunlock()is called at the end, ensuring safe configuration changes.

Supporting References:

Junos PyEZ Documentation:The documentation explains how context managers work in PyEZ, including the automatic invocation ofopen(),close(),lock(), andunlock()methods.