Part-1 OCI Network Design, VCN, and Subnets

OCI Networking Best Practices document, along with examples for better understanding:

1. Scalability with Dynamic Routing Gateway (DRG)

• Feature: The DRG allows you to connect up to 300 Virtual Cloud Networks (VCNs).
• Example: If your organization starts with a single VCN for development, as it grows, you can easily add additional VCNs for production, testing, and staging environments without redesigning the entire network.
• Security: You can place network security appliances, such as firewalls, in the hub VCN to inspect traffic between spoke VCNs.
• Example: A firewall in the hub can monitor and control traffic between a production VCN and a development VCN, ensuring that sensitive production data is protected.

2. VCN Segmentation

• Recommendation: Segment different network environments into separate VCNs for better management and security.
• Example: Create one VCN for production (e.g., vcn-prod-ashburn) and another for non-production (e.g., vcn-nonprod-ashburn). This separation helps prevent accidental access to production resources from non-production environments.
• Common Use Cases:
  • Production vs. Non-Production: Isolating environments to reduce risk.
  • Customer Segmentation: Different VCNs for different clients to ensure data privacy and compliance.

3. Hub-and-Spoke Design

• Tip: Implement a hub-and-spoke architecture to centralize connectivity and management.
• Example: The hub VCN can serve as a central point for shared services (like DNS or logging), while spoke VCNs can be dedicated to specific applications or departments, such as finance or HR.

4. Subnet Planning

• Recommendation: Determine the types of subnets needed before provisioning.
• Example: If you need a public subnet for web servers and a private subnet for databases, plan your CIDR blocks accordingly (e.g., 10.0.1.0/24 for public and 10.0.2.0/24 for private).

5. VCN Flow Logs

• Feature: VCN flow logs capture detailed traffic information.
• Recommendation: Enable flow logs for each subnet after creation.
• Example: If you notice unusual traffic patterns, you can analyze the flow logs to identify the source of the traffic and take appropriate action.
• Log Management: Create a separate log group for better organization.
• Cost Awareness: Be aware that storing logs incurs costs, so enable them judiciously.

6. Project Planning for OCI Network Design

• Recommendation: Allocate time and resources for thorough network design.
• Example: Before launching a new application, spend time mapping out the network layout, including VCNs, subnets, and external connectivity, to avoid issues later.
• Collaboration: Work with Oracle specialists for guidance.
• Design Elements: Include layout, topology, sizing, DNS, and external connectivity in your design.

7. Reference Architectures and Templates

• Tip: Use reference architectures for common deployments as a starting point.
• Example: If deploying Oracle E-Business Suite, refer to Oracle’s provided architecture to ensure best practices are followed.
• Diagram Templates: Utilize OCI diagram templates to visualize your network design effectively.

8. Standard Naming Conventions

• Recommendation: Establish a standard naming convention for network resources.
• Example: Use descriptive names like vcn-prod-ashburn for production VCNs, drg-ashburn for DRGs, and web-sn-sl for security lists. This clarity helps team members understand the purpose of each resource at a glance.
• Naming Considerations: Be cautious with names that cannot be changed later, such as DNS labels.

9. DNS Design with OCI Private DNS

• Feature: OCI Private DNS allows for custom DNS domains and records within your VCNs.
• Recommendation: Integrate DNS resolution across VCNs and on-premise environments early in your design.
• Example: If you have a custom domain like oci.customer.com, you can create DNS records that resolve to resources in different VCNs, facilitating seamless connectivity.

By following these detailed points and examples, organizations can effectively design and manage their OCI networking infrastructure, ensuring scalability, security, and operational efficiency.