Oracle Cloud Infrastructure Foundations — Lesson 3: VCNs, Subnets, Gateways, Load Balancers, DNS, and Database Services

Learning Objectives

• Explain the purpose and operating context of VCNs, CIDR, public and private subnets, security lists, and NSGs.
• Apply internet, NAT, service, and dynamic routing gateways and load balancers, network load balancers, DNS, peering, VPN, and FastConnect awareness in a controlled environment.
• Validate outcomes and troubleshoot risks involving Autonomous Database, DB systems, MySQL, Exadata, and service selection.

Detailed Topics

• VCNs, CIDR, public and private subnets, security lists, and NSGs
• internet, NAT, service, and dynamic routing gateways
• load balancers, network load balancers, DNS, peering, VPN, and FastConnect awareness
• Autonomous Database, DB systems, MySQL, Exadata, and service selection

Instructor Demonstration

Demonstrate VCNs, CIDR, public and private subnets, security lists, and NSGs for a new cloud team selecting basic OCI services for a secure and resilient application; capture the exact configuration, code, command, transaction, query, dashboard, model, schedule, or report evidence that proves the expected result.

Hands-On Exercise

Complete a controlled Oracle Cloud Infrastructure Foundations exercise covering internet, NAT, service, and dynamic routing gateways and load balancers, network load balancers, DNS, peering, VPN, and FastConnect awareness; introduce an exception involving Autonomous Database, DB systems, MySQL, Exadata, and service selection, diagnose it from evidence, apply the smallest reversible correction, and rerun acceptance checks.

1. Confirm scope, prerequisites, identities, dependencies, data, risks, and expected outcome.
2. Perform the course-specific configuration, development, administration, analysis, or business-process workflow.
3. Capture commands, settings, records, logs, screenshots, reports, metrics, or test results.
4. Compare the observed result with acceptance criteria and document corrective or preventive action.

Scenario Analysis

• Identify the technical or business decision and the stakeholders affected by it.
• Compare security, performance, reliability, compliance, cost, usability, and support trade-offs.
• Define rollback, recovery, communication, evidence, ownership, and escalation requirements.

Troubleshooting Guidance

Diagnose issues involving VCNs, CIDR, public and private subnets, security lists, and NSGs, internet, NAT, service, and dynamic routing gateways, load balancers, network load balancers, DNS, peering, VPN, and FastConnect awareness, Autonomous Database, DB systems, MySQL, Exadata, and service selection without making an unverified production change. Separate symptoms from causes, gather time-correlated evidence, test a reversible hypothesis, validate the correction, and record recurrence controls.

Validation Checklist

• The requirement, environment, inputs, dependencies, and expected result are documented.
• The result is reproducible and supported by product-specific evidence.
• Normal, boundary, failure, security, performance, and operational conditions are reviewed.
• Exceptions, rollback, ownership, support actions, and the next improvement priority are recorded.

Lesson Outcome

Learners can apply VCNs, Subnets, Gateways, Load Balancers, DNS, and Database Services in a realistic Oracle Cloud Infrastructure Foundations scenario and defend the result with documented evidence.