JNCIA-DevOps Practice Test 22 — 15 Questions

Question 1

An administrator wants to disable the Junos REST API daemon entirely. Which CLI command achieves this?

Accepted Answer

delete system services jpagent. To disable the jpagent service, the administrator uses the 'delete system services jpagent' command in configuration mode.

Answer

deactivate protocols rest-api

Answer

set system services jpagent disable

Answer

stop system services rest

Question 2

Which TWO characteristics describe JSNAPy snapshot operations? (Choose two)

Accepted Answer

It saves captured operational data into snapshot files for later comparison.. JSNAPy captures snapshots to XML/YAML files and compares them over time.

Answer

It compiles Jinja2 configuration templates directly into Junos CLI commands.

Answer

It replaces PyEZ as the primary library for executing NETCONF RPC calls.

Answer

It modifies the active configuration database automatically upon finding errors.

Question 3

When executing a configuration change via the Junos REST API, what is the role of the HTTP DELETE method?

Accepted Answer

To delete a specific configuration hierarchy or statement from the candidate configuration.. In the context of the Junos REST API, the HTTP DELETE method is used to remove a specific configuration object or subtree, analogous to deleting a statement in the Junos CLI or removing an element in NETCONF.

Answer

To clear operational state counters such as interface packet counters.

Answer

To terminate an active REST API session and revoke the auth token.

Answer

To discard the entire candidate configuration.

Question 4

What is the default TCP port used by the Junos jpagent for unencrypted HTTP REST API connections?

Accepted Answer

3000. The Junos REST API daemon (jpagent) listens on TCP port 3000 by default for HTTP traffic, and port 3443 for HTTPS traffic.

Answer

80

Answer

830

Answer

8080

Question 5

An engineer needs to retrieve the entire candidate configuration in JSON format from a Junos device using the Junos REST API. Which HTTP header must be included in the GET request to ensure the response is returned in JSON format?

Accepted Answer

Accept: application/json. The Accept header with 'application/json' specifies that the client expects the response to be formatted in JSON.

Answer

Transfer-Encoding: chunked

Answer

Content-Type: text/xml

Answer

X-Junos-Data-Format: json

Question 6

Which PyEZ utility module should you import if you need to upgrade the Junos operating system on a remote device via a Python script?

Accepted Answer

from jnpr.junos.utils.sw import SW. The SW utility module from jnpr.junos.utils.sw is used for software installation and upgrades.

Answer

from jnpr.junos.utils.upgrade import Upgrade

Answer

from jnpr.junos.utils.config import Config

Answer

from jnpr.junos.device import OS_Update

Question 7

Which THREE error-tag values defined in NETCONF RFC 6241 may be returned by a Junos device when an edit-config operation fails validation? (Choose three)

Accepted Answer

invalid-value. RFC 6241 error-tags include invalid-value, missing-element, data-exists, and in-use.

Answer

syntax-timeout

Answer

buffer-overflow

Question 8

An engineer writes a Python script using ncclient to push changes to a Junos device. After sending the configuration via <edit-config>, the script needs to make the changes active without dropping the NETCONF session lock prematurely or requiring a separate explicit commit RPC if candidate workflows are bypassed. However, using standard candidate datastore workflow, what is the exact RPC required to activate the candidate configuration?

Accepted Answer

. The RPC is used to commit the candidate configuration to the running configuration datastore in Junos.

Answer

<apply-changes/>

Answer

<save-config/>

Answer

<push-running/>

Question 9

When writing a Python script using PyEZ, how should you handle connection timeout exceptions when attempting to connect to an unreachable Junos device?

Accepted Answer

except ConnectError:. PyEZ raises ConnectError when it fails to establish a NETCONF session with the target device.

Answer

except NetconfConnectionError:

Answer

except DeviceOpenError:

Answer

except socket.timeout:

Question 10

You are writing a script that parses NETCONF responses from Junos. You encounter an element named inside an . What does this indicate?

Accepted Answer

The NETCONF operation completed successfully with no error or data payload to return.. The <ok/> tag indicates that the requested NETCONF operation executed successfully with no data to return.

Answer

The SSH tunnel has been successfully authenticated.

Answer

The candidate configuration has uncommitted changes.

Answer

The device CPU utilization is normal.

Question 11

An automation engineer is trying to retrieve operational data from a Junos device using the REST API. They send an HTTP GET request to the URI path 'http://192.168.1.1:3000/api/font/operational/system/information', but the request fails with a 404 Not Found error. What is the cause of this failure?

Accepted Answer

The URI path contains an invalid prefix segment 'font' instead of the required API root structure.. The correct base path for Junos REST API operational data uses 'rpc' or 'initial' or specific resource endpoints like /api/restful/rit/rpc, but the standard path prefix for RPCs and operational data via the Junos REST API begins with /api/operational/ rather than /api/font/operational/.

Answer

Authentication credentials were missing from the HTTP header.

Answer

The port 3000 is reserved for NETCONF and cannot be used for REST API requests.

Answer

Operational data retrieval requires an HTTP POST method instead of GET.

Question 12

An automation script attempts to unlock a candidate configuration datastore that was previously locked by a different NETCONF session. Which RPC is required to force-terminate that session and release the lock?

Accepted Answer

...

. The RPC allows terminating another active NETCONF session, which automatically releases any locks held by that session.

Answer

Answer

<release-lock session-id="..."/>

Answer

<close-session><session-id>...</session-id></close-session>

Question 13

You want to validate a candidate configuration on a Junos device without committing it using NETCONF. Which RPC accomplishes this?

Accepted Answer

. The RPC checks the consistency and validity of a specified configuration datastore.

Answer

<test-config>

Answer

<check-config>

Answer

<edit-config test-only="true"/>

Question 14

Which Junos XML API output format option allows requesting the output as plain text instead of structured XML?

Accepted Answer

format="text". Junos XML API allows requesting ASCII/text output format by appending the format='text' attribute to RPC requests.

Answer

output="ascii"

Answer

encoding="plain"

Answer

type="string"

Question 15

Which THREE advantages are associated with using the Junos REST API over NETCONF in lightweight automation scripts? (Choose three)

Accepted Answer

Ability to traverse standard HTTP/HTTPS proxies and load balancers easily.. REST API benefits include native JSON parsing support in languages like Python without extra libraries, simple HTTP request/response debugging, and easy traversal through standard web proxies.

Answer

Elimination of the Junos candidate configuration datastore.

Answer

Guaranteed multi-vendor transaction rollbacks across non-Juniper hardware.