JNCIA-DevOps Practice Test 15 — 15 Questions

Question 1

An administrator configures the Junos REST API service. By default, which TCP port does the device listen on for secure HTTPS REST requests?

Accepted Answer

3443. The default TCP port for secure HTTPS requests in the Junos REST API daemon (jpagent) is port 3443.

Answer

443

Answer

8080

Answer

830

Question 2

When configuring the Junos REST API, an administrator restricts access to a specific port and enables SSL. Which configuration statement sets the secure HTTPS port to 8443?

Accepted Answer

set system services jpagent https port 8443. To customize the HTTPS port for the jpagent service in Junos, the administrator uses the 'set system services jpagent https port 8443' command.

Answer

set protocols rest-api https port 8443

Answer

set system services rest port 8443 secure

Answer

set system services netconf https-port 8443

Question 3

Which term describes the practice of continuously building, testing, and validating software or network configurations in an automated pipeline?

Accepted Answer

CI/CD (Continuous Integration / Continuous Deployment). Continuous Integration / Continuous Deployment (CI/CD) describes automated building and testing.

Answer

Manual Change Advisory Board (CAB) review

Answer

Cold-boot disaster recovery

Answer

Static physical cable patching

Question 4

When interacting with Junos devices via NETCONF, which TWO RPC operations are part of standard NETCONF protocol capabilities? (Choose two)

Accepted Answer

. NETCONF standard operations include , , , , etc.

Answer

<reboot-routing-engine-force>

Answer

<format-hard-drive>

Answer

<traceroute-packet>

Question 5

You are reviewing a pull request that updates Junos interface configurations using Jinja2 templates. The template contains a conditional statement checking an interface speed variable. What happens if the variable is undefined during template rendering?

Accepted Answer

Jinja2 raises an undefined error and halts template rendering unless default filters or conditional checks are used.. Jinja2 raises an UndefinedError by default when an undefined variable is evaluated in a template, unless configured otherwise or handled with defined tests.

Answer

The Git repository automatically rejects the push citing syntax errors.

Answer

Junos automatically ignores the missing variable and applies default factory settings.

Answer

The target Junos router enters rescue mode due to corrupted NETCONF RPC messages.

Question 6

Why is it considered a best practice to store sensitive secrets (such as SNMP community strings or API tokens) outside of plaintext Jinja2 templates in a Git repository?

Accepted Answer

To prevent unauthorized exposure of credentials in shared version control systems, utilizing secure secret management tools instead.. Storing secrets in plaintext in version control risks exposure of sensitive credentials to anyone with repository access.

Answer

Because Junos devices do not accept authentication strings longer than 8 characters.

Answer

To prevent Jinja2 rendering engines from running out of memory.

Answer

To ensure that NETCONF sessions always default to unencrypted plain text.

Question 7

What is the primary benefit of decoupling network configuration data (YAML/JSON) from presentation templates (Jinja2) in network automation?

Accepted Answer

It allows non-engineers to modify device variables without altering the core template logic, promoting the DRY principle.. Separating data from templates allows the same template to be reused across multiple devices with different data sets, adhering to DRY principles.

Answer

It eliminates the need for any version control system.

Answer

It converts all configuration files into binary format to save disk space.

Answer

It forces the Junos device to run all configuration commits in parallel across all line cards.

Question 8

Which Junos automation architecture component provides standardized, model-driven interfaces using NETCONF and gRPC/gNMI to manage and monitor Junos devices?

Accepted Answer

Junos XML API and schema definitions. Junos API and data modeling components like NETCONF and gRPC provide structured, programmatic access to the Junos control plane.

Answer

The Junos CLI pipe filter 'match' command

Answer

Proprietary screen-scraping CLI scripts running in a crontab daemon

Answer

The physical console cable attached to the Routing Engine

Question 9

An automation engineer is designing a Junos network automation workflow and needs to select the component of the Junos automation architecture responsible for parsing XML and JSONRPC client requests and interacting directly with the Junos kernel and daemons. Which component fulfills this role?

Accepted Answer

mgd (Management Daemon). MGD (Management Daemon) is the primary user interface handler in Junos OS. It processes CLI commands, Netconf XML requests, and JSON-RPC APIs, translating them into operations interacting with the Junos kernel and individual routing daemons via RRDS.

Answer

jails

Answer

rpd (Routing Protocol Daemon)

Answer

jsd (Junos Script Daemon)

Question 10

A DevOps engineer is designing a CI/CD pipeline for validating Junos configuration changes prior to deployment. Which THREE actions are typically performed during the automated CI pipeline 'test' or 'validate' stage? (Choose THREE)

Accepted Answer

Performing dry-run validation checks against staging or virtual Junos instances (vSRX). CI validation stages typically run linting checks, static syntax validation against Junos schemas, and unit testing of templates or automation code before deployment staging.

Answer

Immediately rebooting the production core routing engine to apply all updates

Answer

Manually logging into physical CLI consoles to troubleshoot cabling

Question 11

A network engineer is exploring the core components of the Junos automation architecture. Which TWO components are native Junos daemons or automation frameworks directly involved in script execution or API processing? (Choose TWO)

Accepted Answer

jsd (Junos Script Daemon). jsd (Junos Script Daemon) executes local SLAX and Python event scripts, and mgd (Management Daemon) processes XML/NETCONF/JSON-RPC automation requests.

Answer

snmpd (Simple Network Management Protocol Daemon)

Answer

sshd (Secure Shell Daemon)

Answer

httpd (Hypertext Transfer Protocol Daemon)

Question 12

An automation engineer is using Git and needs to undo the last local commit while keeping the modified changes in their working directory as unstaged changes. Which command should they execute?

Accepted Answer

git reset HEAD~1 (or git reset --mixed HEAD~1). 'git reset --soft HEAD~1' or 'git reset HEAD~1' resets the commit while keeping working tree files modified/staged depending on flags. 'git reset HEAD~1' defaults to mixed (keeps changes unstaged).

Answer

git reset --hard HEAD~1

Answer

git checkout -f master

Answer

git revert --purge

Question 13

In Junos XML API, what is the XML namespace associated with Junos-specific RPCs and operational tags?

Accepted Answer

http://xml.juniper.net/junos/*/junos-rpc. Junos XML API elements use specific namespaces like http://xml.juniper.net/junos/12.1X46/junos-sw for software or general rpc namespaces.

Answer

http://www.cisco.com/ns/yang/cisco-se

Answer

urn:juniper:params:xml:ns:netconf:base:1.0

Answer

urn:ietf:params:xml:ns:netconf:base:1.0

Question 14

An engineer needs to modify a configuration parameter using the Junos REST API via an HTTP PUT request. They include the Content-Type header as 'application/json'. However, the device rejects the payload. What is the correct Content-Type or Accept header requirement for configuration manipulation payload representation in Junos REST API?

Accepted Answer

application/vnd.juniper.netconf.config+json. Junos REST API supports both JSON and XML representations. When sending configuration payloads, the Content-Type must match the format being transmitted, such as application/vnd.juniper.netconf.config+json or application/json depending on the API version, but application/vnd.juniper.netconf.config+json is specifically designed for structural configuration mapping.

Answer

application/x-www-form-urlencoded

Answer

text/xml only

Answer

multipart/form-data

Question 15

An organization is implementing a Git-based version control strategy for Junos network configurations. Which THREE practices are considered standard DevOps workflows when managing network configurations in Git? (Choose THREE)

Accepted Answer

Tagging specific repository commits to mark official production releases or maintenance versions. Standard Git workflows involve storing configurations as plain text templates, using pull/merge requests for peer review before merging, and tagging repository commits corresponding to official maintenance windows or production releases.

Answer

Directly committing experimental production changes to the master branch without review

Answer

Encrypting all configuration text files using binary compressed archives inside Git