JNCIA-DevOps Practice Exam 4 — 20 Questions

Question 1

What Jinja2 feature allows you to include the contents of another template file into your main configuration template?

Accepted Answer

{% include 'filename.j2' %}. The {% include %} tag allows inserting another template's content.

Answer

{% insert 'filename.j2' %}

Answer

{% import 'filename.j2' %}

Answer

Question 2

Which THREE exceptions can be raised by PyEZ during script execution when interacting with a Junos device? (Choose three)

Accepted Answer

RpcError. PyEZ defines specific exceptions in jnpr.junos.exception for connection, configuration, and RPC errors.

Answer

DatabaseLockedError

Answer

TemplateRenderError

Question 3

You are using the PyEZ SW utility to install a new Junos image on a device. Which method parameter allows the script to automatically reboot the device after a successful installation?

Accepted Answer

reboot=True. The val parameter or reboot=True flag is typically used depending on the specific SW.upgrade() call signature. Specifically, reboot=True forces the reload.

Answer

auto_reboot=1

Answer

reload_after_install=True

Answer

action='reboot'

Question 4

When designing a custom PyEZ Table and View mapping in Python, what configuration parameter in the YAML definition file specifies the RPC or CLI command executed to gather the raw data?

Accepted Answer

rpc:. The 'rpc' or 'command' keyword in a PyEZ Table YAML definition specifies the underlying command to run.

Answer

get-rpc:

Answer

exec:

Answer

command_string:

Question 5

An automation engineer is writing a Python script using Junos PyEZ to connect to a device. Which module and class must be imported to instantiate a device object representing the Junos target?

Accepted Answer

from jnpr.junos.device import Device. The Device class from the jnpr.junos module is the foundational class used in PyEZ to manage connections and sessions with Junos devices.

Answer

from jnpr.junos.rpcs import RPC

Answer

from jnpr.junos.facts import Facts

Answer

from jnpr.junos.utils.sw import SW

Question 6

You are rendering a Jinja2 template in Python that includes a loop over a list of VLANs. Which Jinja2 block syntax correctly iterates over a list named 'vlan_list'?

Accepted Answer

{% for vlan in vlan_list %} ... {% endfor %}. Jinja2 uses {% for item in list %} ... {% endfor %} syntax for iteration.

Answer

{{ for vlan in vlan_list }} ... {{ endfor }}

Answer

[for vlan in vlan_list] ... [endfor]

Answer

<% for vlan in vlan_list %> ... <% endif %>

Question 7

When using Jinja2 templates in Python to generate configurations, how can you load a template file from disk prior to rendering it with variables?

Accepted Answer

Template(open('template.j2').read()). Environment and FileSystemLoader are used to load templates from a directory path.

Answer

template.open('template.j2')

Answer

import_template('template.j2')

Answer

jinja2.load_file('template.j2')

Question 8

When using PyEZ to push a configuration, you want to log out all NETCONF XML traffic exchanged between the script and the Junos device for debugging purposes. How do you enable this logging in Python?

Accepted Answer

Configuring Python logging for the 'jnpr.junos' logger with DEBUG level. Python's standard logging module configured for the jnpr.junos logger enables debug output.

Answer

import jnpr.junos.debug; jnpr.junos.debug.enable()

Answer

dev.rpc.trace(enabled=True)

Answer

dev.debug = True

Question 9

What is JSNAPy primarily used for in Junos network automation?

Accepted Answer

Taking operational state snapshots and verifying device health. JSNAPy (Junos Snapshot Administrator) is used to capture operational state snapshots of Junos devices and compare them to detect changes or anomalies.

Answer

Compiling Junos CLI operational commands into Python bytecode

Answer

Performing automated firmware upgrades across clusters

Answer

Generating static configuration templates

Question 10

You want to run a JSNAPy verification test via Python code. Which Python class should you import and instantiate to execute the snapshot comparison programmatically?

Accepted Answer

from jnpr.jsnapy import SnapAdmin. The JSNAPy class is imported from jnpr.jsnapy to execute snapshot checks programmatically.

Answer

from jnpr.jsnapy.verify import VerifyEngine

Answer

from jnpr.junos.utils.jsnapy import JSNAPy

Answer

from jnpr.jsnapy.runner import JSNAPyRunner

Question 11

When writing a Python script that connects to multiple Junos devices concurrently using PyEZ, which Python module is commonly used to manage thread pooling and parallel execution?

Accepted Answer

concurrent.futures. Concurrent futures or threading modules handle parallel execution in Python.

Answer

jnpr.junos.parallel

Answer

multiprocessing.device

Answer

asyncio.netconf

Question 12

You need to write a Python script that extracts interface status from a Junos device using PyEZ and converts the XML output directly into a Python dictionary. Which utility or function can assist with this conversion?

Accepted Answer

Using PyEZ Table and View abstractions. The XMLtoPy function from jnpr.junos.factory or standard table/view mappings helps convert XML to Python data structures.

Answer

dev.rpc.convert_to_dict()

Answer

json.loads(dev.rpc.get_interface_information())

Answer

etree.to_dict()

Question 13

When configuring a JSNAPy test file, which section defines the specific RPCs or CLI commands that should be executed to gather operational data?

Accepted Answer

command: or rpc:. The snapcheck or check configuration structure uses test definitions pointing to specific commands.

Answer

action:

Answer

device_credentials:

Answer

template:

Question 14

Which Python library does PyEZ depend on under the hood for managing secure SSH connections and NETCONF framing?

Accepted Answer

ncclient. PyEZ relies on ncclient for NETCONF over SSH transport.

Answer

paramiko

Answer

fabric

Answer

netmiko

Question 15

Which TWO methods or attributes are valid when using the PyEZ SW utility to manage Junos software? (Choose two)

Accepted Answer

sw.install(remote_path='/var/tmp/image.tgz'). SW utility methods include install, upgrade, and checking device readiness.

Answer

sw.rollback_software()

Answer

sw.get_os_facts()

Answer

sw.commit_os()

Question 16

Which TWO commands or tools are associated with running JSNAPy snapshot verifications from a CLI environment? (Choose two)

Accepted Answer

jsnapy --snap. JSNAPy execution is invoked via command line tool 'jsnapy'.

Answer

pyez-snap --run

Answer

junos-snapshot --verify

Answer

juniper-snapshot-admin --test

Question 17

When working with the PyEZ Config utility, which THREE actions can be performed using the configuration context manager or its methods? (Choose three)

Accepted Answer

cu.validate(). The Config utility supports locking, loading configurations from various sources, validating, and rolling back.

Answer

cu.gather_facts()

Answer

cu.upgrade_os()

Question 18

An automation script needs to check if a Junos device supports a specific feature before executing an RPC. Which PyEZ property can be checked to inspect the software version loaded on the device?

Accepted Answer

dev.facts['version']. dev.facts['version'] holds the Junos OS version string.

Answer

dev.get_version()

Answer

dev.version

Answer

dev.os_version

Question 19

Which TWO methods are valid for loading configuration data into the PyEZ Config utility from different sources? (Choose two)

Accepted Answer

cu.load(text='set system hostname router1', format='set'). Config.load supports string data, file paths, and template rendering results.

Answer

cu.load(template_file='config.j2', engine='jinja2')

Answer

cu.load(database='active')

Answer

cu.load(action='commit')

Question 20

An automation script needs to compare pre- and post-change states on a Junos device using JSNAPy (Junos Snapshot Administrator). Which configuration file format is used by JSNAPy to define snapshot checks and test assertions?

Accepted Answer

YAML. JSNAPy uses YAML configuration files to define which RPC commands to run and what expected values or expressions should be evaluated against the resulting snapshots.

Answer

XML

Answer

JSON

Answer

INI