JNCIA-DevOps Junos Automation Stack And DevOps Concepts Practice Test 2 — 15 Questions

Question 1

What is a primary characteristic of a DevOps culture when applied to network operations (NetOps)?

Accepted Answer

Emphasizing collaboration, automation, continuous testing, and shared responsibility between network and development teams.. NetOps applies DevOps principles like collaboration, automation, and CI/CD to network engineering.

Answer

Siloing network operations strictly away from software development teams.

Answer

Eliminating all documentation in favor of verbal communication.

Answer

Relying entirely on manual change approval boards for every minor configuration change.

Question 2

Which command is used in Git to save staged changes to the local repository with a descriptive commit message?

Accepted Answer

git commit -m "message". 'git commit' records changes to the local repository.

Answer

git add

Answer

git push

Answer

git save

Question 3

An automation pipeline tests Junos configuration changes against a virtual Junos device (such as vSRX or cRPD) in a CI environment before deploying to physical hardware. What is this practice called?

Accepted Answer

Virtual staging and pre-deployment validation testing. Testing against virtualized network functions in a staging or CI environment is known as lab validation or digital twinning/staging.

Answer

Production traffic shedding

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Static code linting

Answer

Hardware refactoring

Question 4

In a Junos automation environment, what role does a schema (such as YANG or Junos XSD) play when interacting with NETCONF?

Accepted Answer

It defines the structural rules, data types, and valid hierarchy for configuration and operational data models.. YANG or XSD schemas define the data model structure, types, and constraints for configuration and operational data.

Answer

It encrypts the communication channel between the client and the Junos device.

Answer

It acts as a firewall filter blocking unauthorized IP addresses on the management interface.

Answer

It compiles Python scripts into executable machine code for the Routing Engine CPU.

Question 5

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 6

What is the primary function of a version control system (VCS) like Git in a Junos automation workflow?

Accepted Answer

To track configuration history, enable collaboration, and provide a single source of truth for network designs.. A VCS tracks changes over time, enabling collaboration, rollback, and audit trails.

Answer

To act as a high-speed packet forwarding engine for BGP routes.

Answer

To compile Python automation scripts into binary executables.

Answer

To monitor real-time CPU utilization on Junos routing engines.

Question 7

A network engineer writes a Python script using Junos PyEZ to push a configuration change. The script uses the ConfigTable or Config class. What mechanism does PyEZ use under the hood to ensure the configuration lock is released even if the script encounters an unhandled exception?

Accepted Answer

Python context managers ('with' statements) that automatically release locks and clean up session state upon exit.. Python context managers (using the 'with' statement) automatically handle acquiring and releasing locks and rolling back candidate changes on exception in PyEZ.

Answer

NETCONF keepalive timers that drop the SSH session after 1 second.

Answer

A UNIX cron job that reboots the router every 5 minutes.

Answer

Hardware watchdog timers built into the Routing Engine ASIC.

Question 8

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.. Unit testing validates individual components (like a specific macro, template, or script function) to ensure they produce the expected output.

Answer

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

Answer

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

Answer

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

Question 9

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 10

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)

Answer

Microsoft PowerShell Active Directory module

Answer

Arista eAPI Python client library

Question 11

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 12

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.. An <rpc-error> tag in NETCONF indicates that the request could not be processed successfully due to syntax, permission, or validation errors.

Answer

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

Answer

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

Answer

The physical optical link on the management port has failed.

Question 13

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 14

An engineer wants to inspect the differences between two committed configurations on a Junos device using the CLI or automation tools. Which operation does this correspond to in Junos configuration management?

Accepted Answer

Comparing configuration revisions (e.g., rollback comparison) to audit modifications before committing.. Comparing configuration revisions is done using comparison features (e.g., 'show configuration | compare').

Answer

Running a traceroute across the management network

Answer

Performing a NETCONF <discard-changes> operation

Answer

Reloading the Junos kernel image

Question 15

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. DevOps brings increased agility, faster deployments, better visibility, and reduced human error through automation and version control.

Answer

Elimination of all network documentation requirements

Answer

Mandatory requirement for physical console cables on every device

Answer

Exclusive reliance on manual CLI configuration commands