200-901 Practice Question: A network automation team uses a CI/CD pipeline

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Automated unit tests that verify syntax of configuration files

  Why it's wrong here

  Syntax checks confirm files parse correctly but never exercise the configuration against a device or validate intended behaviour, so semantic errors pass through. The pipeline needs tests run against a simulated or lab environment before production. Unit tests suit catching formatting and schema mistakes early, not verifying operational correctness.

• ✗

  Peer review of code only

  Why it's wrong here

  Peer review catches logic and style problems but produces no executable evidence that the configuration applies cleanly, so it cannot guarantee validation. The pipeline requires automated tests executed against a representative environment. Review alone fits teams needing design feedback, not gatekeeping deployment on functional verification.

• ✗

  Manual testing by the network engineer after deployment

  Why it's wrong here

  Testing after deployment means faulty configuration has already reached production, which is precisely what the pipeline must prevent. Validation has to occur in a pre-production stage against a simulated or lab device. Post-deployment checks suit monitoring rollback triggers, not the pre-deployment gate the question asks for.

• ✓

  Deploying to a staging environment that mirrors production

  Why this is correct

  A staging environment mirroring production lets the pipeline execute configuration changes and validation tests against a realistic replica before promotion. This catches errors pre-deployment, satisfying the requirement that changes be validated prior to reaching production systems.

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