JNCIA-DevOps Multiple Select — 50 Questions

Question 1

Which TWO of the following are valid extensions commonly used for YAML files? (Choose two)

Accepted Answer

.yaml. YAML files commonly use either .yaml or .yml file extensions.

Answer

.xml

Answer

.jsn

Answer

.txt

Question 2

Which TWO file formats are commonly used for structuring network configuration data and automation templates in Junos DevOps pipelines? (Choose two)

Accepted Answer

JSON. YAML and JSON are standard data serialization formats used alongside Jinja2 templates.

Answer

Proprietary binary core dump format

Answer

Raw bitmap image (.bmp) format

Answer

Windows executable (.exe) format

Question 3

An automation developer is designing a script that reads routing policy parameters from a configuration file. Which TWO data formats are natively supported and commonly used across Junos automation toolchains like PyEZ, Ansible, and REST APIs for data serialization? (Choose two)

Accepted Answer

YAML. JSON and YAML are the primary lightweight data serialization formats universally utilized across modern network automation toolchains and APIs.

Answer

BMP

Answer

RTF

Answer

EXE

Question 4

In Git version control, which TWO commands are used to integrate changes from one branch into another? (Choose two)

Accepted Answer

git merge. Git uses 'merge' and 'rebase' to integrate changes between branches.

Answer

git init

Answer

git status

Answer

git clone

Question 5

Which THREE mechanisms are valid methods for authenticating and establishing a NETCONF session with a Junos device? (Choose three)

Accepted Answer

Remote RADIUS or TACACS+ AAA server integration via SSH transport. NETCONF on Junos runs over SSH, supporting SSH keys, username/password, and AAA integration.

Answer

Anonymous guest access without credentials

Answer

Unencrypted cleartext Telnet on TCP port 23

Question 6

Which TWO features are supported by YAML but are notably absent in standard JSON? (Choose two)

Accepted Answer

Anchors and aliases for data reuse within the document.. YAML supports comments and anchors/aliases, whereas standard JSON supports neither.

Answer

Native browser execution support without parsing libraries.

Answer

Strict enforcement of double quotes on all string keys.

Answer

Strict indentation-based block scoping.

Question 7

Which TWO characteristics are true regarding the Junos REST API? (Choose two)

Accepted Answer

It supports both JSON and XML data formats.. The Junos REST API runs on jpagent (default port 3000 for HTTP and 3443 for HTTPS) and natively supports both JSON and XML data formats.

Answer

It requires client-side compilation of proprietary C++ libraries.

Answer

It requires a persistent SSH session for every transaction.

Answer

It runs on TCP port 830 exclusively.

Question 8

Which THREE advanced features or methods are available on a PyEZ Device instance for session management and inspection? (Choose three)

Accepted Answer

dev.timeout property to get or set NETCONF RPC timeout values. PyEZ Device instances provide methods to check connection status, manage timeout values, and inspect capabilities.

Answer

dev.reload_session() for refreshing device facts

Answer

dev.commit_timeout for software installation timing

Question 9

Which TWO configuration steps are required to enable the Junos REST API with basic security settings? (Choose two)

Accepted Answer

set system services jpagent https. To enable the REST API, you must enable the jpagent service and optionally enable HTTPS for secure transport.

Answer

set system netconf secure-mode

Answer

set protocols rest-api state active

Answer

set system services rest enable

Question 10

Which TWO error response categories or HTTP status codes are commonly returned by the Junos REST API when client requests are malformed or unauthorized? (Choose two)

Accepted Answer

401 Unauthorized. 401 Unauthorized is returned for bad or missing credentials, and 400 Bad Request is returned for malformed payload syntax.

Answer

202 Accepted

Answer

504 Gateway Timeout

Answer

100 Continue

Question 11

Which THREE architectural features distinguish the Junos REST API from traditional CLI screen-scraping (CLI automation via expect scripts)? (Choose three)

Accepted Answer

Resource-based URI routing that maps directly to configuration and operational models.. REST API provides structured data formats (JSON/XML), deterministic API contracts with HTTP status codes, and programmatic resource addressing, whereas screen-scraping relies on fragile text parsing.

Answer

Strict enforcement of synchronous modal CLI configuration blocks.

Answer

Requirement for VT100 terminal emulation buffers.

Question 12

When developing Python scripts that utilize PyEZ and Jinja2, which THREE best practices ensure robust and maintainable automation code? (Choose three)

Accepted Answer

Using the PyEZ Config context manager to ensure locks are released and rollbacks occur on error. Best practices include proper exception handling, using context managers, and separating templates from logic.

Answer

Hardcoding administrative passwords inside template files for easy rendering

Answer

Avoiding device.close() calls to keep network sessions open permanently

Question 13

Which THREE features are provided by the Junos REST API daemon (jpagent) when running on a Junos device? (Choose three)

Accepted Answer

Translation between REST requests/JSON/XML payloads and Junos configuration/operational structures.. The jpagent daemon provides HTTP/HTTPS server capabilities, authentication handling against local/AAA databases, and translation between HTTP requests/JSON/XML and Junos internal RPC/configuration structures.

Answer

Kernel-level packet forwarding optimization for ASIC line cards.

Answer

Autonomous BGP route reflection across core routing instances.

Question 14

When configuring advanced options for the Junos REST API jpagent, which THREE parameters or sub-statements can be configured under the 'set system services jpagent' hierarchy? (Choose three)

Accepted Answer

traceoptions. Under 'set system services jpagent', administrators can configure HTTPS, custom HTTP/HTTPS ports, and connection timeouts or limits depending on Junos software version support.

Answer

bgp-peer-group

Answer

ethernet-switching

Question 15

Which TWO statements are true regarding PyEZ Table and View definitions? (Choose two)

Accepted Answer

A View defines how individual fields within the returned XML elements are mapped to Python dictionary keys.. Tables map to RPCs and Views map to item fields using YAML.

Answer

Tables can only be used to modify device configurations, not read operational state.

Answer

Tables require Jinja2 templates to parse raw XML output.

Answer

Views replace the need to instantiate a Device object.

Question 16

Which TWO statements are true regarding the NETCONF protocol hello message exchange? (Choose two.)

Accepted Answer

Both client and server exchange capabilities using XML elements containing URI strings.. During the initial NETCONF hello message exchange, both the client and server advertise their supported capabilities using URIs, and the session ID is assigned by the server.

Answer

The client uses the hello message to lock the configuration database before session initialization.

Answer

The client hello message must include the list of YANG modules it intends to modify during the session.

Answer

The hello message exchange is optional if a pre-shared SSH key is used for authentication.

Question 17

When writing Jinja2 templates for Junos configurations, which THREE control flow or filtering constructs are valid? (Choose three)

Accepted Answer

{% for vlan in vlans %} ... {% endfor %}. Jinja2 supports filters, loops, and conditional statements.

Answer

[# foreach item in list #] ... [# endfor #]

Answer

<< if interface_active >> ... << endif >>

Question 18

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 19

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 20

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