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JNCIS-DevOps study materials
JNCIS-DevOps study resources

JNCIS-DevOps practice questions

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Question 1DevOps fundamentals and culture

In a DevOps context, what does the practice of 'blameless postmortem' primarily aim to achieve?

  1. Assigning accountability to the engineer who triggered the incident
  2. Reducing the number of incidents reported to management
  3. Documenting the incident for legal and compliance audits
  4. Learning how system conditions allowed the failure and preventing recurrence Correct answer.

Explanation

A blameless postmortem assumes people act reasonably given the information and tools available, so the focus shifts to the system conditions and process gaps that made the failure possible. The goal is organizational learning and concrete follow-up actions, not punishment, which would suppress honest reporting.

Question 2DevOps fundamentals and culture

Which statement best describes the 'Three Ways' of DevOps as framed by Gene Kim?

  1. Plan, build, and run as three sequential organizational silos
  2. Automation first, documentation second, and monitoring third
  3. Cost reduction, headcount reduction, and outsourcing of operations
  4. Systems thinking, amplifying feedback loops, and a culture of continual experimentation and learning Correct answer.

Explanation

The Three Ways describe fast flow from development to operations, rapid and amplified feedback in the other direction, and a culture that supports continual experimentation and learning. Together they frame DevOps as a systemic and cultural change rather than a tooling checklist.

Question 3DevOps fundamentals and culture

A team wants to shorten its lead time for changes. Which change most directly supports the first way of DevOps?

  1. Requiring separate operations sign-off for production access
  2. Reducing batch sizes so work moves through the pipeline in smaller increments Correct answer.
  3. Increasing the number of environments to isolate each developer
  4. Adding a manual change advisory board review before every deployment

Explanation

The first way emphasizes fast flow of work from development to operations, and smaller batch sizes reduce queueing, review overhead, and integration risk. This shortens lead time and makes feedback more frequent.

Question 4DevOps fundamentals and culture

Which metric set is commonly associated with the DORA research on software delivery performance?

  1. Server count, CPU utilization, and storage consumed
  2. Lead time for changes, deployment frequency, change failure rate, and time to restore service Correct answer.
  3. Lines of code, number of commits, and test coverage percentage
  4. Team size, budget spent, and number of releases per year

Explanation

DORA's delivery performance metrics are lead time for changes, deployment frequency, change failure rate, and time to restore service. They balance speed (throughput) with stability so teams cannot game one dimension at the expense of the other.

Question 5DevOps fundamentals and culture

A team deploys frequently but its change failure rate keeps rising. Which action best reflects a DevOps improvement approach?

  1. Stop deploying frequently until the failure rate returns to zero
  2. Investigate the failure causes and strengthen automated testing and progressive delivery safeguards Correct answer.
  3. Move responsibility for failures to the operations team
  4. Add a mandatory two-week manual regression cycle before each release

Explanation

DevOps treats speed and stability as complementary, so the response to rising failures is to find and remove the causes, typically through better automated testing, canary releases, and fast rollback. This preserves delivery flow while improving reliability.

Question 6DevOps fundamentals and culture

What is the primary cultural effect of cross-functional teams that own a service from code to production?

  1. Shared ownership and faster feedback between development and operations Correct answer.
  2. Guaranteed zero production incidents
  3. Reduced need for any documentation
  4. Elimination of all operational work

Explanation

When one team owns a service through its full lifecycle, developers and operators share accountability and see the consequences of their changes directly. That shortens feedback loops and reduces the throw-it-over-the-wall dynamic between silos.

Question 7DevOps fundamentals and culture

Which practice most directly embodies the DevOps principle of 'you build it, you run it'?

  1. Developers carry on-call responsibility for the services they build Correct answer.
  2. Deployments are performed only by a dedicated release manager
  3. Operations writes runbooks that developers never review
  4. A separate NOC team handles all production alerts

Explanation

The phrase means the team that builds a service also operates and supports it, so it feels operational pain directly and designs for reliability. Developers on call for their own services is the clearest expression of that accountability.

Question 8DevOps fundamentals and culture

How does a DevOps culture typically view failure in a complex production system?

  1. As an opportunity to learn and improve system resilience Correct answer.
  2. As a reason to add more approval gates before deployment
  3. As an unavoidable cost that should be hidden from customers
  4. As evidence that the responsible engineer should be replaced

Explanation

In complex systems, failures are expected, so DevOps culture treats them as learning opportunities that inform resilience improvements. This view supports transparency, blameless analysis, and iterative hardening of the system.

Question 9DevOps fundamentals and culture

A platform team provides a self-service internal developer platform. Which outcome best demonstrates that it supports DevOps culture?

  1. Developers must file a ticket for every environment change
  2. All infrastructure changes are batched into a monthly release
  3. Developers can provision compliant environments and deploy without manual handoffs Correct answer.
  4. The platform team approves every pull request across all product teams

Explanation

A self-service platform encodes organizational standards as automated guardrails, letting product teams move independently without waiting on tickets. That reduces handoffs and queue time while keeping compliance intact, which is the cultural goal of platform engineering.

Question 10DevOps fundamentals and culture

What is the main purpose of a value stream mapping exercise in a DevOps transformation?

  1. To calculate the salary cost of each delivery team
  2. To replace all manual testing with a single vendor tool
  3. To select which programming language the teams should use
  4. To identify where work waits and where handoffs slow the flow from idea to customer Correct answer.

Explanation

Value stream mapping makes visible the steps, queues, and handoffs between idea and customer value delivery. Teams use it to find the largest sources of delay and waste, then target improvements such as automation or reduced approvals.

Question 11DevOps fundamentals and culture

A team measures lead time from code commit to production. Which factor most directly inflates this metric?

  1. Frequent small pull requests
  2. Long queues waiting for manual approval before deployment Correct answer.
  3. Automated rollback on failed health checks
  4. High unit test coverage in the codebase

Explanation

Lead time for changes includes all waiting between commit and running in production, and manual approval queues are a classic source of delay. Reducing or automating those gates is a common flow improvement.

Question 12DevOps fundamentals and culture

Which behavior most clearly reflects psychological safety in a DevOps team?

  1. Managers require written justification for every incident
  2. Only senior engineers are permitted to speak during incident reviews
  3. Engineers avoid reporting near misses to protect their performance reviews
  4. Engineers openly raise concerns about risky changes without fear of punishment Correct answer.

Explanation

Psychological safety means people believe they can speak up about risks, mistakes, and concerns without retaliation. That openness is what makes blameless postmortems and early risk detection possible in high-performing teams.

Question 13DevOps fundamentals and culture

In the context of DevOps culture, what distinguishes an error from a violation?

  1. An error is an unintended action in a complex system, while a violation is a deliberate deviation from a known rule Correct answer.
  2. An error is always caused by automation, while a violation is caused by people
  3. An error requires disciplinary action, while a violation does not
  4. Errors occur only in development, while violations occur only in production

Explanation

Safety science distinguishes unintended errors, which are expected in complex work and should be designed around, from violations, which are conscious departures from known rules. This distinction lets organizations respond proportionately instead of treating every failure as misconduct.

Question 14DevOps fundamentals and culture

Which combination best characterizes the CALMS framework used to assess DevOps readiness?

  1. Culture, Automation, Lean, Measurement, and Sharing Correct answer.
  2. Compliance, Auditing, Logging, Metrics, and Scanning
  3. Cost, Agility, Latency, Monitoring, and Security
  4. Containers, APIs, Load balancers, Microservices, and Storage

Explanation

CALMS stands for Culture, Automation, Lean, Measurement, and Sharing, and it is used as a maturity lens for DevOps adoption. It emphasizes that tooling alone is insufficient without cultural and measurement change.

Question 15DevOps fundamentals and culture

A team adopting CALMS finds strong automation but poor cross-team knowledge sharing. Which action best addresses the gap?

  1. Purchase additional CI/CD licenses
  2. Establish communities of practice and internal tech talks to spread knowledge Correct answer.
  3. Increase the number of deployment pipelines
  4. Add more automated tests to the pipeline

Explanation

The Sharing dimension of CALMS concerns how knowledge, practices, and lessons move between teams. Communities of practice, internal talks, and shared documentation directly build that capability, whereas more tooling does not.

Question 16DevOps fundamentals and culture

Which statement best explains why DevOps teams favor small, frequent deployments over large, infrequent ones?

  1. Frequent deployments eliminate the need for monitoring
  2. Large deployments always fail because they exceed network bandwidth
  3. Small deployments remove the need for version control
  4. Smaller changes are easier to review, test, and roll back, reducing blast radius Correct answer.

Explanation

Smaller change sets contain fewer interacting variables, are easier to validate, and can be reverted quickly if something goes wrong. This reduces the blast radius of any single change and shortens the time to diagnose failures.

Question 17DevOps fundamentals and culture

What role does a chaos engineering experiment play in a mature DevOps culture?

  1. It deliberately injects failures to validate that resilience mechanisms work as expected Correct answer.
  2. It is used to punish teams that cause incidents
  3. It replaces the need for automated testing
  4. It guarantees that production will never fail

Explanation

Chaos engineering introduces controlled failures to verify that systems degrade gracefully and that recovery mechanisms actually work. It is a learning and validation practice that complements testing and observability rather than replacing them.

Question 18DevOps fundamentals and culture

Which statement most accurately describes the relationship between DevOps and SRE?

  1. SRE forbids automation and relies on manual operations
  2. SRE and DevOps are unrelated disciplines with no shared principles
  3. DevOps replaces SRE entirely once adopted
  4. SRE is a specific implementation of DevOps principles that uses error budgets and service level objectives Correct answer.

Explanation

Site reliability engineering applies DevOps ideas with concrete practices such as SLOs, error budgets, and toil reduction. It is often described as a particular way of implementing DevOps, not a competing or unrelated discipline.

Question 19DevOps fundamentals and culture

A team has an SLO with an error budget. What does it mean when the error budget is exhausted?

  1. The team should pause risky feature releases and prioritize reliability work Correct answer.
  2. The team should ignore reliability and continue shipping features
  3. The team must immediately delete the service
  4. The error budget has no relationship to release decisions

Explanation

An error budget is the amount of unreliability the SLO permits, and exhausting it signals that reliability is at risk. The usual response is to freeze or slow risky changes and focus on stabilizing the service until the budget recovers.

Question 20DevOps fundamentals and culture

Which practice best supports the DevOps goal of reducing 'toil' in operations?

  1. Hiring more operators to perform the same manual tasks
  2. Automating repetitive, manual operational tasks so engineers can focus on improvement work Correct answer.
  3. Documenting manual procedures in greater detail without automating them
  4. Increasing the number of manual approvals in the deployment process

Explanation

Toil is repetitive, manual, and automatable work that scales linearly with service growth. Automating it frees engineers to focus on higher-value engineering and reduces human error.

Question 21DevOps fundamentals and culture

Which pattern best describes the 'shift left' principle in a DevOps culture?

  1. Deferring testing until after deployment
  2. Moving all production support to a later phase after release
  3. Moving security and quality checks earlier into the development lifecycle Correct answer.
  4. Reducing the number of developers on a team

Explanation

Shift left means addressing quality, security, and compliance concerns as early as possible, where defects are cheaper and faster to fix. It embeds these checks into development workflows rather than relying on late-stage gates.

Question 22DevOps fundamentals and culture

A security team wants to embed controls into developer workflows without slowing delivery. Which approach aligns best with DevSecOps culture?

  1. Integrating automated security scanning and policy-as-code checks into the CI/CD pipeline Correct answer.
  2. Requiring a manual security review before every commit
  3. Blocking all deployments until a quarterly audit completes
  4. Moving security responsibility exclusively to a separate team

Explanation

DevSecOps brings security into the delivery pipeline as automated, codified checks so issues are found early and consistently. This preserves flow while making security a shared responsibility rather than a late gate.

Question 23DevOps fundamentals and culture

Which statement best captures the concept of 'antifragility' as applied to DevOps systems?

  1. Systems should never be tested in production-like environments
  2. Systems should avoid all stress and change
  3. Systems can improve their resilience by experiencing and adapting to controlled stress Correct answer.
  4. Systems become weaker every time they encounter failure

Explanation

Antifragile systems do more than withstand stress; they improve because of it when the stress is controlled and observable. Practices such as game days and controlled fault injection apply this idea to build stronger systems.

Question 24DevOps fundamentals and culture

A team's deployment frequency is high, but mean time to restore service is very long. Which cultural or process change most likely addresses the problem?

  1. Improving observability, runbooks, and on-call practices so incidents are detected and resolved faster Correct answer.
  2. Adding more manual approval gates before deployment
  3. Reducing deployment frequency to hide failures
  4. Removing monitoring to reduce alert noise

Explanation

Long restore times usually indicate weak detection, unclear ownership, or poor incident response tooling. Strengthening observability, runbooks, and on-call practices improves recovery without sacrificing deployment speed.

Question 25DevOps fundamentals and culture

Which statement best explains why DevOps emphasizes measuring outcomes such as customer satisfaction rather than only output metrics like lines of code?

  1. Output metrics are always inaccurate
  2. Outcome metrics reflect whether the work delivered value and guide improvement decisions Correct answer.
  3. Customer satisfaction is impossible to measure
  4. Lines of code directly correlate with business value

Explanation

Outcome metrics show whether changes actually improved the product or service for users, which is the point of delivery work. Output metrics can be gamed and often fail to reflect value, so DevOps culture favors measures tied to real results.

Question 26DevOps fundamentals and culture

In the DevOps culture model, what is the primary purpose of blameless postmortems after a production incident?

  1. To produce a formal document that satisfies auditors without changing any engineering practice.
  2. To reconstruct the technical and organizational causes of the incident and improve the system so it cannot recur. Correct answer.
  3. To identify the individual engineer responsible so that management can apply the correct disciplinary action.
  4. To assign fault to the vendor whose component failed and negotiate a service credit.

Explanation

Blameless postmortems focus on systemic causes rather than individual fault, because punishing people suppresses the reporting that DevOps depends on. The output is a set of concrete improvements to tooling, process, and safeguards that reduce the chance or impact of recurrence.

Question 27DevOps fundamentals and culture

A product team wants to reduce handoffs between development and operations. Which organizational change best supports this DevOps goal?

  1. Create a separate release engineering group that receives code from developers and deploys it.
  2. Require developers to submit a ticket to the operations queue for every production change.
  3. Form a team that owns its service through design, build, deployment, and on-call operation. Correct answer.
  4. Rotate developers through operations for one week per year while keeping separate reporting lines.

Explanation

DevOps reduces handoffs by making a single team accountable for the full lifecycle of its service, which shortens feedback loops and aligns incentives. Temporary rotations or intermediary groups still leave ownership split and preserve the handoff the change is meant to remove.

Question 28DevOps fundamentals and culture

Which statement best describes the 'Three Ways' of DevOps as articulated by Gene Kim?

  1. Measure velocity, measure utilization, and measure compliance.
  2. Systems thinking, amplified feedback loops, and a culture of continual experimentation and learning. Correct answer.
  3. Automate everything, outsource operations, and reduce headcount.
  4. Plan, build, and run as three sequential phases owned by three separate departments.

Explanation

The Three Ways describe the flow of work from development to operations, fast feedback from right to left, and a culture of continual experimentation and learning. They are principles about flow and learning, not a departmental phase model or a set of utilization metrics.

Question 29DevOps fundamentals and culture

A team claims to practice continuous delivery. Which evidence most strongly supports that claim?

  1. The team maintains a long-lived release branch that is merged back to trunk quarterly.
  2. Deployments are performed by a dedicated operations group during a monthly maintenance window.
  3. Every change that passes automated tests can be deployed to production on demand by the team. Correct answer.
  4. The team holds a weekly release meeting to decide which features are ready for production.

Explanation

Continuous delivery means the software is always in a deployable state and the team can release on demand, typically through an automated pipeline. Periodic release meetings, long-lived branches, and fixed maintenance windows all indicate that deployment is still a scheduled, separate activity.

Question 30DevOps fundamentals and culture

What is the main purpose of a blameless incident review that includes a timeline and contributing factors?

  1. To compare individual engineers' performance during the incident.
  2. To satisfy regulatory reporting requirements for outages.
  3. To determine which team should pay for the downtime.
  4. To generate learning that changes tools, processes, and safeguards across the organization. Correct answer.

Explanation

The value of an incident review comes from turning experience into systemic improvement, not from assigning cost or evaluating people. Documenting contributing factors helps teams change the conditions that allowed the failure.

Question 31DevOps fundamentals and culture

A team's deployment pipeline takes four hours because integration tests run serially. Which action best aligns with DevOps principles for improving flow?

  1. Parallelize the test suite and remove redundant stages so feedback arrives faster. Correct answer.
  2. Move integration testing to a nightly job so the pipeline appears faster.
  3. Add more manual approval gates to catch defects earlier in the pipeline.
  4. Increase the deployment batch size so fewer pipeline runs are needed.

Explanation

DevOps seeks to shorten feedback loops and reduce batch size; parallelizing tests and removing waste directly improves flow. Hiding slow tests in a nightly job or adding manual gates delays feedback rather than improving it.

Question 32DevOps fundamentals and culture

Which practice best demonstrates the DevOps principle of 'fail fast' in a development workflow?

  1. Running a small automated test suite on every commit so broken changes are caught within minutes. Correct answer.
  2. Requiring a full manual regression cycle before any code is merged to the main branch.
  3. Allowing developers to disable failing tests temporarily to keep the build green.
  4. Deploying only at the end of a release cycle to minimize the number of failures.

Explanation

Fail fast means detecting problems as early and cheaply as possible, which automated tests on every commit achieve. Manual regression cycles, disabling tests, and long release cycles all delay or hide failure signals.

Question 33DevOps fundamentals and culture

A platform team wants to measure whether its internal developer platform is improving developer productivity. Which metric is most aligned with DevOps outcomes?

  1. The percentage of developers who report they can deploy a change to production without contacting another team. Correct answer.
  2. The total lines of code committed to the platform repository.
  3. The number of tickets closed by the platform team per sprint.
  4. The number of meetings held between platform and product teams.

Explanation

A platform succeeds when it enables teams to self-serve and deploy independently, which is a flow and autonomy outcome. Activity metrics such as tickets closed, lines of code, or meeting counts do not demonstrate reduced friction for developers.

Question 34DevOps fundamentals and culture

In a DevOps culture, what is the most appropriate response when a team member discovers that a production change caused a subtle data corruption?

  1. Escalate to senior management so the responsible engineer can be identified.
  2. Report the issue immediately, roll back or mitigate, and then run a blameless review to find systemic causes. Correct answer.
  3. Wait until the next scheduled release to include a fix with other changes.
  4. Quietly fix the data and avoid documenting the event to prevent blame.

Explanation

DevOps culture rewards transparency and fast mitigation, followed by learning that prevents recurrence. Hiding the issue, delaying the fix, or seeking individual blame all increase risk and undermine trust.

Question 35DevOps fundamentals and culture

Which statement best explains why DevOps teams treat documentation and runbooks as code?

  1. It transfers ownership of documentation to a separate technical writing team.
  2. It guarantees that documentation is always accurate without any maintenance.
  3. It removes the need for any human to read documentation during an incident.
  4. It allows documentation to be versioned, reviewed, and tested alongside the software it describes. Correct answer.

Explanation

Treating documentation as code brings it into the same version control, review, and testing workflow as software, which keeps it closer to reality. It does not eliminate human readers, guarantee accuracy without maintenance, or move ownership away from the team.

Question 36DevOps fundamentals and culture

A team wants to adopt a blameless culture but managers keep asking 'who broke it?' during incidents. Which action most directly addresses this cultural barrier?

  1. Stop holding incident reviews so that no one can be blamed.
  2. Require engineers to sign a statement accepting responsibility before reviews begin.
  3. Publish a policy that incident reviews focus on contributing factors and system conditions, and have leaders model that behavior. Correct answer.
  4. Restrict incident review attendance to managers only.

Explanation

Culture changes when leaders visibly reinforce the desired behavior and when the review process is explicitly designed around systemic factors. Avoiding reviews or requiring responsibility statements would reinforce blame rather than remove it.

Question 37DevOps fundamentals and culture

What does the 'shift right' concept add to a DevOps strategy that already emphasizes shifting testing left?

  1. It moves all testing to the operations team after deployment.
  2. It extends feedback and experimentation into production through monitoring, observability, and controlled release techniques. Correct answer.
  3. It replaces automated testing with manual exploratory testing in production.
  4. It delays security reviews until after the system is retired.

Explanation

Shift right complements shift left by recognizing that production is where real user behavior and failure modes appear, so teams invest in observability, canary releases, and experimentation. It does not move testing to a separate team or replace automation.

Question 38DevOps fundamentals and culture

Which combination of practices best supports the DevOps goal of fast, reliable feedback from production to development?

  1. Annual penetration tests and quarterly architecture reviews.
  2. A weekly meeting where developers read customer support tickets.
  3. Manual log reviews performed by the operations team each morning.
  4. Centralized logging, distributed tracing, and automated alerting tied to service-level objectives. Correct answer.

Explanation

Observability tooling such as centralized logs, tracing, and SLO-based alerting gives developers timely, actionable signals about production behavior. Infrequent reviews or manual morning checks are too slow and too coarse to support fast feedback.

Question 39DevOps fundamentals and culture

A team measures mean time to restore service (MTTR) and finds it is high because responders spend most of an incident locating the right logs and dashboards. Which cultural or process change most directly improves MTTR?

  1. Require responders to write a detailed root cause analysis before they are allowed to mitigate.
  2. Invest in observability and runbooks so responders can diagnose and mitigate faster, and rehearse this through game days. Correct answer.
  3. Add more approval steps before responders can roll back a deployment.
  4. Increase the change approval board's review frequency.

Explanation

MTTR improves when responders can quickly see what is wrong and act, which observability, runbooks, and rehearsal provide. Requiring analysis before mitigation or adding approvals slows restoration and worsens the metric.

Question 40DevOps fundamentals and culture

What is the primary reason DevOps teams prefer to make infrastructure changes through version-controlled code rather than manual console changes?

  1. It eliminates the need for any testing of infrastructure changes.
  2. It makes changes reviewable, repeatable, and auditable, reducing configuration drift. Correct answer.
  3. It removes the need for operations skills on the team.
  4. It guarantees that infrastructure costs will decrease.

Explanation

Infrastructure as code brings changes into version control so they can be reviewed, reproduced, and audited, which reduces drift and surprise. It does not remove the need for testing or operations skills, nor does it guarantee lower cost.

Question 41Automation and configuration management

In a Junos commit workflow, which command stages configuration changes in the candidate configuration without activating them on the device?

  1. commit confirmed 5
  2. set system host-name edge-1 Correct answer.
  3. commit and-quit
  4. commit check

Explanation

Configuration statements entered with set (or edit) modify only the candidate configuration; nothing becomes active until a commit is issued. The commit variants validate or activate changes, and commit and-quit also exits configuration mode.

Question 42Automation and configuration management

Which Junos feature lets you verify a configuration change is safe by automatically reverting it unless you confirm within a set time?

  1. commit synchronize
  2. commit full
  3. commit script
  4. commit confirmed Correct answer.

Explanation

commit confirmed activates the candidate configuration but schedules an automatic rollback unless you run commit again before the timer expires. This protects against locking yourself out with a bad management or routing change.

Question 43Automation and configuration management

Which statement describes the role of the Junos candidate configuration?

  1. It is the factory-default configuration loaded at first boot
  2. It is a backup stored only on the alternate Routing Engine
  3. It is a working copy edited before commit and can be discarded without affecting the active config Correct answer.
  4. It is the running configuration that immediately takes effect as statements are typed

Explanation

Junos edits a private candidate copy of the configuration; changes take effect only at commit, and rollback 0 or a discard returns to the active state. This two-step model allows validation before activation.

Question 44Automation and configuration management

Which Junos command displays the differences between the candidate configuration and the currently active configuration?

  1. show system commit
  2. show configuration | display set
  3. show configuration | compare rollback 1
  4. show | compare Correct answer.

Explanation

Within configuration mode, show | compare lists the pending candidate changes against the active configuration. This is the standard way to review edits before committing.

Question 45Automation and configuration management

Which protocol does Junos use to push configuration and operational state to a centralized automation or management platform?

  1. NETCONF over SSH Correct answer.
  2. LLDP
  3. RADIUS accounting
  4. SMTP

Explanation

Junos supports NETCONF over SSH as a programmatic interface for configuration and state retrieval, commonly used by automation controllers. It carries XML-encoded RPCs rather than human-oriented CLI text.

Question 46Automation and configuration management

What is the purpose of a Junos rescue configuration?

  1. To store a known-good configuration that can be loaded if the active config is lost or broken Correct answer.
  2. To encrypt the configuration file on the Routing Engine
  3. To schedule automatic commits at fixed intervals
  4. To hold the candidate configuration while it is being edited

Explanation

A rescue configuration is a saved known-good baseline that can be restored with rollback rescue, providing recovery when changes render the device unreachable. It is separate from the normal rollback history.

Question 47Automation and configuration management

Which Junos automation mechanism runs Python or SLAX scripts triggered by events such as a commit or a system log message?

  1. Event scripts Correct answer.
  2. Firewall filters
  3. BGP route reflectors
  4. Class of service schedulers

Explanation

Event scripts are On-box automation that react to triggers like commit, SNMP, or syslog events and can perform actions or generate output. They are part of the Junos automation toolkit alongside commit and op scripts.

Question 48Automation and configuration management

Which data serialization format is used by the Junos XML API and NETCONF to encode configuration and operational responses?

  1. CSV
  2. INI
  3. XML Correct answer.
  4. YAML

Explanation

Junos encodes NETCONF and XML API requests and replies in XML, with configuration elements mirroring the CLI hierarchy. This structured encoding is what makes programmatic parsing reliable.

Question 49Automation and configuration management

An engineer wants to apply a configuration change but have Junos validate it for syntax and semantic errors without activating it. Which command should be used?

  1. commit
  2. commit check Correct answer.
  3. commit confirmed
  4. rollback 0

Explanation

commit check parses the candidate configuration and runs validation checks without activating changes. It is the standard pre-flight step before an actual commit.

Question 50Automation and configuration management

A change to a management interface caused loss of SSH access. Which Junos capability best recovers the previous working configuration automatically?

  1. commit confirmed with a short timer Correct answer.
  2. commit synchronize
  3. commit full
  4. commit script

Explanation

commit confirmed reverts to the prior configuration automatically if the operator does not reconfirm within the timer, which recovers access after a lockout. Reconnecting and committing again makes the change permanent.