JNCIA-DevOps Junos Automation Stack And DevOps Concepts Practice Test 3 — 15 Questions

Question 1

In a CI/CD pipeline for network changes, what is the role of automated unit testing?

Accepted Answer

To verify that individual configuration modules, templates, or script functions produce expected outputs before integration.. Automated unit testing in a CI/CD pipeline verifies that individual components, such as configuration modules, templates, or script functions, produce the expected outputs. This ensures that each part works correctly before integration, catching errors early in the development cycle.

Answer

To measure the exact fiber cable distance between two data centers.

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To automatically upgrade the Junos OS kernel on all cluster nodes simultaneously.

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To physically test the optical transceiver power levels using laser beams.

Question 2

Which Junos automation toolset relies heavily on XML over NETCONF and provides robust Python libraries tailored specifically for Junos network devices?

Accepted Answer

Junos PyEZ. Junos PyEZ is the Python library tailored specifically for Junos devices using NETCONF.

Answer

Cisco IOS XE Embedded Event Manager (EEM)

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Microsoft PowerShell Active Directory module

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Arista eAPI Python client library

Question 3

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.

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It eliminates the need for any version control system.

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

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

Question 4

During a NETCONF session with a Junos device, an automation script issues an RPC to load a configuration. The device returns a response containing an <rpc-error> tag. What does this indicate?

Accepted Answer

The configuration or RPC request failed validation, syntax checking, or execution constraints on the device.. In NETCONF (RFC 6241), the element is returned inside the when the server cannot successfully process the RPC. It signals that the request failed validation, hit a syntax error, violated a data-model constraint, or was rejected by the device's configuration engine — not that the session or hardware failed. The error contains sub-elements like , , , and that describe the exact failure.

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The Junos routing engine is operating at 100% CPU capacity.

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The NETCONF session has successfully terminated with a normal exit code.

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The physical optical link on the management port has failed.

Question 5

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.

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Manual Change Advisory Board (CAB) review

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Cold-boot disaster recovery

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Static physical cable patching

Question 6

Which TWO benefits are gained by applying DevOps principles to Junos network management? (Choose two)

Accepted Answer

Consistent, repeatable deployments through automation and version control. Option C is correct because DevOps principles applied to Junos network management emphasize infrastructure-as-code, where configurations are stored in version control systems (e.g., Git) and deployed through automation tools such as Ansible, PyEZ, or Junos Terraform provider, yielding consistent and repeatable deployments. Option E is correct because DevOps fundamentally breaks down silos between teams, fostering shared ownership and improved collaboration between network engineers and software developers through shared tooling, CI/CD pipelines, and common repositories. Option A is incorrect because documentation remains essential in DevOps environments; automation and version control supplement, but do not eliminate, documentation requirements. Option B is incorrect because physical console cables are not mandated by DevOps principles; out-of-band management may still be used for recovery, but DevOps does not require a console cable on every device. Option D is incorrect because DevOps explicitly moves away from exclusive manual CLI configuration toward programmatic, automated configuration via NETCONF, REST API, or Junos automation frameworks.

Answer

Elimination of all network documentation requirements

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Mandatory requirement for physical console cables on every device

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Exclusive reliance on manual CLI configuration commands

Question 7

You are configuring a webhook in your version control system to trigger an automated CI/CD pipeline whenever a developer pushes a configuration commit to the main branch of your Junos automation repository. What security mechanism should be implemented on the receiving pipeline webhook endpoint?

Accepted Answer

Validating a shared secret token or HMAC cryptographic signature sent in the webhook request headers.. Webhooks should be secured using secret tokens or HMAC signatures to ensure requests genuinely originate from the trusted VCS platform.

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Opening TCP port 22 directly to the public internet without firewall rules.

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Hardcoding the developer's Linux user password inside the webhook listener script.

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Disabling all SSL/TLS certificates to allow unencrypted HTTP packet inspection.

Question 8

When designing a version control workflow for Junos configurations using Git, which THREE practices are considered industry best standards? (Choose three)

Accepted Answer

Using feature branches for developing new configuration changes before merging into main. Option B is correct because feature branches isolate new Junos configuration changes from the main branch, allowing development and validation without destabilizing production-ready configurations before a controlled merge. Option D is correct because peer reviews and pull request approvals enforce a four-eyes principle, catching errors, policy violations, or unintended commit/rollback commands before changes reach the main branch. Option E is correct because semantic or descriptive commit messages document the intent of each configuration update, which is essential for audit trails, troubleshooting, and correlating commits with change tickets in Junos automation workflows. Option A does not belong because bypassing automated testing removes validation of syntax, commit checks, and rollback safety, increasing outage risk. Option C does not belong because storing plaintext administrative passwords in public Git repositories exposes credentials and violates security best practices; secrets should be managed with tools like Ansible Vault, HashiCorp Vault, or Junos encrypted passwords.

Answer

Completely bypassing automated testing to speed up deployments

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Storing plaintext administrative passwords directly in public Git repositories

Question 9

Which TWO components are essential parts of a model-driven network automation architecture on Junos devices? (Choose two)

Accepted Answer

YANG data models defining the structure and constraints of configuration and state data. Option A is correct because YANG data models are the foundational schema in a model-driven architecture, formally defining the structure, hierarchy, types, and constraints of both configuration and state data on Junos devices, enabling programmatic and vendor-neutral interaction. Option B is correct because model-driven automation requires standardized, model-aware management protocols — NETCONF (typically over SSH on port 830) and gRPC/gNMI — to transport YANG-modeled data and support operations like get-config, edit-config, and telemetry, rather than relying on human-readable CLI output. Options C, D, and E are not part of a model-driven architecture: Telnet terminal emulation, screen-scraping PERL scripts that parse raw CLI text, and physical serial port multiplexers all represent legacy, CLI-centric or hardware-centric approaches that lack structured data models and standardized programmatic interfaces.

Answer

Manual terminal emulation sessions using Telnet

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Proprietary screen-scraping PERL scripts parsing raw CLI text

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Physical serial port multiplexers

Question 10

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

Accepted Answer

git merge. git merge (B) is correct because it integrates changes from one branch into another by combining their commit histories, typically creating a merge commit when the target branch has diverged. git rebase (E) is also correct because it integrates changes by replaying commits from one branch onto another, producing a linear history. git init (A) only initializes a new repository and does not integrate branch changes. git status (C) merely reports working tree and staging state without modifying history. git clone (D) copies a remote repository locally but does not merge or rebase branches.

Answer

git init

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git status

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git clone

Question 11

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

Accepted Answer

JSON. JSON (A) is correct because Junos automation tooling such as PyEZ, Junos REST API, and NETCONF/RESTCONF interactions commonly serialize structured configuration and template data as JSON, which is easily parsed by Python scripts in DevOps pipelines. YAML (B) is correct because it is the native format for Ansible playbooks and Jinja2-based automation templates widely used to structure Junos configuration data declaratively in CI/CD workflows. The proprietary binary core dump format (C) is a diagnostic artifact produced on crashes, not a human-readable data-structuring format for configuration. The raw bitmap image format (D) and Windows executable format (E) are unrelated to network configuration data or automation templates and cannot represent structured configuration.

Answer

Proprietary binary core dump format

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Raw bitmap image (.bmp) format

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Windows executable (.exe) format

Question 12

In a CI/CD pipeline configured for Junos network changes, which THREE automated testing steps are typically performed before production deployment? (Choose three)

Accepted Answer

Static code linting of YAML data and Jinja2 templates. Option C is correct because CI/CD pipelines for Junos automation typically begin with static code linting of YAML data files and Jinja2 templates to catch syntax errors, formatting issues, and template rendering problems before any configuration is pushed. Option D is correct because a dry-run candidate configuration validation on a test Junos device or virtual instance (e.g., using 'commit check' or 'load merge' in a lab/vSRX/vMX environment) verifies that the generated configuration is syntactically and semantically accepted by Junos without affecting production. Option E is correct because automated schema validation against YANG models ensures the intended configuration data conforms to the device's data model, catching invalid leaf values, wrong types, or unsupported nodes early in the pipeline. Option A is not a testing step but a physical hardware maintenance action, and Option B is a manual human process unrelated to automated CI/CD validation, so neither belongs in an automated pre-deployment test suite.

Answer

Physical replacement of router power supply units

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Manual approval of physical fiber patch cables by a security guard

Question 13

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

Accepted Answer

. Option B, , is correct because it is a base NETCONF protocol operation defined in RFC 6241 that retrieves configuration data from a specified datastore (such as or ), and it is one of the mandatory capabilities every NETCONF server must support. Option E, , is also correct because it is a standard NETCONF operation from RFC 6241 used to load, merge, replace, create, or delete configuration data in a target datastore, making it a core part of NETCONF's configuration-management capabilities. The remaining options are Junos-specific or vendor-proprietary RPCs rather than standard NETCONF operations: and are Junos extension RPCs for device maintenance, and is a Junos operational RPC for troubleshooting, none of which are defined in the base NETCONF protocol specification.

Answer

<reboot-routing-engine-force>

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<format-hard-drive>

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<traceroute-packet>

Question 14

Which TWO tools or platforms are commonly used for version control and hosting of Junos automation code repositories? (Choose two)

Accepted Answer

GitHub. GitHub (C) is correct because it is a widely used web-based platform built on Git that provides repository hosting, branching, pull requests, and CI/CD integration for storing and collaborating on Junos automation code such as Python scripts, Jinja2 templates, and YAML playbooks. GitLab (E) is also correct because it is a Git-based DevOps platform offering self-managed or SaaS repository hosting, merge requests, and built-in CI/CD pipelines commonly used to manage and deploy Junos automation content. The remaining options do not belong: Adobe Photoshop (A) is an image-editing application, Microsoft Word (B) is a document word processor, and VLC Media Player (D) is a multimedia player — none of these provide Git-based version control or code repository hosting.

Answer

Adobe Photoshop

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Microsoft Word

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VLC Media Player

Question 15

Which THREE principles are foundational to the DevOps movement when applied to network engineering? (Choose three)

Accepted Answer

Continuous monitoring and feedback loops for network telemetry. Option A is correct because DevOps network engineering depends on continuous monitoring and feedback loops—streaming telemetry via SNMP, gNMI, syslog, or NetFlow into observability platforms—so that changes are validated and issues detected immediately rather than discovered later. Option D is correct because the DevOps culture emphasizes shared responsibility between network, development, and operations teams, plus blameless post-mortems and rapid learning from failures, which is essential for safely iterating on network changes. Option E is correct because automating repetitive provisioning and configuration tasks—using tools such as Ansible, Terraform, or Python scripts against APIs—is a core DevOps practice that removes manual drift and enables consistent, repeatable network deployments. Option B does not belong because strict siloing directly contradicts DevOps's cross-functional collaboration and shared ownership model. Option C does not belong because relying solely on annual manual audits is a slow, reactive practice that DevOps replaces with continuous automated validation and monitoring.

Answer

Strict siloing of operational teams from software developers

Answer

Relying solely on annual manual network audits