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OCI Multicloud Architect Associate study materials
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OCI Multicloud Architect Associate: OCI Multicloud Networking

OCI Multicloud Architect Associate · Work through your exam, one topic at a time.

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OCI Multicloud Networking

OCI Multicloud Networking

This domain tests private connectivity between OCI VCNs and other clouds: interconnect choices, routing, CIDR planning, security controls, and failure modes. The exam expects you to distinguish a dedicated interconnect from an IPsec VPN and to design bidirectional routing, not just a tunnel.

Core rules and concepts

  • Oracle Interconnect for Azure combines OCI FastConnect and Azure ExpressRoute through a partner fabric in supported metro pairs. Oracle Interconnect for Google Cloud combines FastConnect with Google Cloud Interconnect. These are private, predictable paths; a site-to-site VPN over the internet is a fallback, not an equivalent.
  • In OCI, attach the VCN to a dynamic routing gateway (DRG), add routes for the remote CIDR to the DRG route table, and allow traffic in security lists or NSGs. In Azure, attach the VNet to an ExpressRoute gateway and add user-defined routes; in Google Cloud, use the Interconnect attachment and VPC routes and firewall rules.
  • CIDRs must not overlap across VCNs, VNets, and VPCs. Overlap forces NAT or re-addressing and breaks many database designs.
  • Interconnects are metro- and region-scoped. Cross-region traffic can hairpin and add latency; place the database and app in the same metro where possible.
  • Use private IPs and private endpoints. Do not expose database ports to the public internet to work around routing gaps.

Worked example

OCI VCN 10.0.0.0/16 hosts a reporting service; Azure VNet 10.1.0.0/16 hosts the app. In the same supported metro, order Oracle Interconnect for Azure. On OCI, route 10.1.0.0/16 to the DRG and allow TCP 1521 from 10.1.0.0/16. On Azure, route 10.0.0.0/16 to the ExpressRoute gateway and allow TCP 1521 from 10.0.0.0/16. Test both directions with traceroute and database client connections; asymmetric routing usually appears as one-way failures.

Traps

Assuming the interconnect automatically advertises all routes; forgetting the return route or NSG rule; overlapping CIDRs; using a VPN and expecting interconnect-level latency; assuming one interconnect covers every region; and leaving database ports open to the internet as a shortcut.