Oracle Cloud Oracle Interconnect for Google Cloud Tutorial: Architecture, Pricing, Use Cases, and Hands-On Guide for Multicloud

1. Introduction

What this service is

Oracle Interconnect for Google Cloud is a private network connectivity service that links Oracle Cloud Infrastructure (OCI) and Google Cloud through dedicated, high-throughput connections—designed for multicloud architectures where workloads and data span both clouds.

One-paragraph simple explanation

If you run some applications in Google Cloud and others (or your databases) in Oracle Cloud, Oracle Interconnect for Google Cloud gives you a private, predictable network path between them. Instead of sending traffic over the public internet, you route it over dedicated interconnect infrastructure to improve latency, stability, and security posture.

One-paragraph technical explanation

Technically, Oracle Interconnect for Google Cloud provides private Layer 3 routing between OCI VCNs and Google Cloud VPC networks using BGP (dynamic routing). On OCI you typically connect via Dynamic Routing Gateway (DRG) and the underlying private connectivity constructs used by OCI networking (commonly associated with FastConnect patterns). On Google Cloud you typically connect using Cloud Interconnect/Cross-Cloud Interconnect with Cloud Router and VLAN attachments. Exact provisioning steps and resource names can vary by region pairing and the current console workflows—verify in official docs for your chosen regions.

What problem it solves

It solves the core problem of reliable, private, high-performance connectivity between OCI and Google Cloud for multicloud deployments—reducing reliance on internet-based VPNs, improving performance consistency for latency-sensitive apps, and enabling more secure data flows between clouds.

2. What is Oracle Interconnect for Google Cloud?

Official purpose (what it’s for)

Oracle Interconnect for Google Cloud is intended to enable private connectivity between Oracle Cloud and Google Cloud so customers can build and operate multicloud solutions with lower latency and higher throughput than typical internet paths.

Service naming and positioning can evolve (for example, Google may refer to “Cross-Cloud Interconnect” on its side). Always confirm the latest terminology and supported region pairings in the official OCI and Google Cloud documentation.

Core capabilities

Private IP connectivity between OCI and Google Cloud (no public internet traversal for data plane traffic).
Dynamic routing using BGP, enabling route exchange and easier operations as networks evolve.
High bandwidth and low latency compared to internet VPNs (specific bandwidth options depend on the offering in your paired regions—verify in official docs).
Redundancy design patterns, typically using multiple attachments/circuits and diverse edge devices (exact redundancy model depends on region pairing and how you provision).

Major components (conceptual building blocks)

On the Oracle Cloud (OCI) side, common components include: – VCN (Virtual Cloud Network): Your OCI private network with subnets. – DRG (Dynamic Routing Gateway): The OCI edge router for private connectivity and route distribution. – Route tables / route distributions: Where you control propagation and forwarding. – Security Lists / Network Security Groups (NSGs): Traffic filtering in OCI. – Private connectivity construct (often aligned with FastConnect-style designs): The mechanism used to establish private connectivity from OCI to external networks.

On the Google Cloud side, common components include: – VPC network: Your Google private network. – Cloud Router: BGP-speaking router used to exchange routes dynamically. – (Cross-Cloud) Interconnect / VLAN attachments: Google’s connectivity primitives used to connect to external networks. – Firewall rules: Google VPC firewall policy allowing required flows.

Service type

Network connectivity / interconnect service for multicloud architectures.
Not a compute, storage, or application service—its role is connectivity and routing.

Scope: regional/global/project/tenancy

Oracle Interconnect for Google Cloud is typically: – Region-pair–dependent (available only for certain OCI region ↔ Google Cloud region pairings). – Scoped to: – An OCI tenancy (and compartments) for resource creation and IAM. – A Google Cloud project (and potentially specific VPC networks) for provisioning and IAM.

The connectivity itself is not “global by default”—it’s anchored to where the interconnect exists. You can still build broader topologies (hub-and-spoke, shared services, multi-region), but you must design routing carefully.

How it fits into the Oracle Cloud ecosystem

Oracle Interconnect for Google Cloud fits primarily into OCI’s Networking stack: – It complements OCI networking constructs like VCN, DRG, and network security controls. – It supports OCI services that benefit from multicloud connectivity (for example, application tiers in Google Cloud connecting to databases or services in OCI, or Oracle services consumed from Google Cloud).

3. Why use Oracle Interconnect for Google Cloud?

Business reasons

Multicloud flexibility: Keep workloads where they best fit (e.g., analytics in Google Cloud, Oracle databases in Oracle Cloud).
Time-to-value: Reduces the need for custom carrier circuits and complex do-it-yourself colocation routing designs (exact operational model depends on region pairing).
Vendor alignment: Built for Oracle Cloud ↔ Google Cloud coexistence strategies, including partner-led service integrations.

Technical reasons

Lower latency and more consistent network performance than internet-based paths.
Higher bandwidth options than typical VPN tunnels (verify bandwidth SKUs in official docs).
BGP-based dynamic routing, enabling:
Controlled route advertisement
Failover patterns
Reduced manual route updates

Operational reasons

Predictability: Dedicated interconnect paths are generally more stable than the public internet.
Simplified change management with BGP when subnets grow or new networks appear.
Standard network patterns: Route tables, BGP, firewall rules, monitoring—concepts your network/SRE teams already know.

Security/compliance reasons

Reduced internet exposure: Traffic can stay on private connectivity.
Better control of routing boundaries and route advertisement.
Supports layering additional controls:
TLS at the application layer
Optional overlay encryption (e.g., IPsec over interconnect) when required by policy

Scalability/performance reasons

Better suited for:
Data replication
High-throughput service-to-service calls
Latency-sensitive APIs
Hybrid-ish control planes and shared services

When teams should choose it

Choose Oracle Interconnect for Google Cloud when: – You have production traffic that needs stable performance between OCI and Google Cloud. – You want private connectivity rather than public internet VPN. – You need BGP route exchange and enterprise routing patterns. – Your workloads are in supported paired regions (availability is the gating factor).

When they should not choose it

Avoid (or delay) using it when: – Your workloads are small and tolerant of internet variability; IPsec VPN might be enough. – Your regions are not supported (or latency to the nearest interconnect location defeats the purpose). – You need connectivity quickly for a short-lived dev/test project and procurement/provisioning time is too high. – Your network plan has overlapping CIDRs or unclear routing ownership; you should fix IP planning first.

4. Where is Oracle Interconnect for Google Cloud used?

Industries

Common in industries with strict security and reliability requirements: – Financial services and fintech – Healthcare and life sciences – Retail and e-commerce – SaaS and enterprise software – Telecom and media – Public sector (subject to region/compliance constraints)

Team types

Cloud platform teams building standardized connectivity patterns
Network engineering teams managing BGP and routing governance
DevOps/SRE teams operating multicloud services
Security teams enforcing segmentation and auditability
Data platform teams moving data between clouds

Workloads

App tier in Google Cloud (e.g., GKE) calling databases/services in OCI
Data replication and backup flows
Internal APIs between microservices split across clouds
Batch data pipelines where private egress reduces exposure

Architectures

Hub-and-spoke network with shared services in one cloud and workloads in another
Split-tier architecture: compute in GCP, database in OCI
Dual-run migration: old system in one cloud, new in the other, with private sync
Hybrid enterprise network: on-prem ↔ OCI ↔ GCP, where OCI DRG can act as a connectivity hub (design carefully to avoid unintended transitive routing)

Production vs dev/test usage

Production: Strong fit when you need predictable performance and private routing.
Dev/test: Often used when dev/test must validate production-like network behavior; however, costs and provisioning lead time can be too high for small ad-hoc environments—teams may use VPN in dev/test and interconnect in production.

5. Top Use Cases and Scenarios

Below are realistic scenarios where Oracle Interconnect for Google Cloud is commonly justified.

1) Google Kubernetes Engine (GKE) app tier + OCI database tier

Problem: App services in GKE need low-latency access to Oracle databases hosted in OCI.
Why this service fits: Private, stable connectivity reduces jitter and improves response times.
Example: Customer runs microservices on GKE and uses Oracle Autonomous Database in OCI; services connect privately over interconnect.

2) Oracle Database@Google Cloud–adjacent connectivity patterns

Problem: Multicloud solutions require reliable OCI↔GCP network paths as part of an Oracle–Google integrated design.
Why this service fits: Oracle Interconnect for Google Cloud is the purpose-built connectivity layer for Oracle–Google multicloud patterns.
Example: Apps in GCP call Oracle services that reside in OCI; interconnect provides private routing.

3) High-throughput data replication between clouds

Problem: Replicating data over internet VPN is slow and inconsistent.
Why this service fits: Dedicated path + higher bandwidth options (verify) improves replication windows.
Example: Nightly bulk transfers from GCP analytics environment to OCI storage or vice versa.

4) Active/active service mesh across clouds (careful design)

Problem: Need cross-cloud service-to-service calls with predictable latency.
Why this service fits: Private connectivity reduces unknown internet variability.
Example: A shared auth service in OCI consumed by workloads in GCP.

5) Migration with coexistence (dual-run)

Problem: Migrating from OCI to GCP (or the reverse) needs a stable coexistence period.
Why this service fits: Improves reliability while systems exchange traffic and data.
Example: Gradually move stateless services to GCP while keeping the database in OCI temporarily.

6) Centralized security inspection (hub firewall) for multicloud flows

Problem: Need a controlled inspection point for traffic crossing clouds.
Why this service fits: Interconnect can route through a security VCN/VPC where inspection appliances run.
Example: Traffic from GCP workloads to OCI passes through an OCI firewall VCN attached to a DRG.

7) Shared internal APIs hosted in OCI for multiple GCP projects

Problem: Several GCP teams need private access to shared services in OCI.
Why this service fits: DRG routing + compartment governance on OCI side, Cloud Router/VPC controls on GCP side.
Example: Payments API in OCI consumed by multiple GCP business units.

8) Private access to OCI object storage endpoints (via private networking patterns)

Problem: Apps in GCP need to exchange objects with OCI without using public endpoints.
Why this service fits: Interconnect provides private network reachability; you still must design endpoint exposure properly (verify OCI private endpoint options for your service).
Example: Data pipeline writes results to OCI Object Storage; traffic stays private.

9) Enterprise identity and logging split across clouds

Problem: Central SIEM/logging platform in one cloud needs private ingestion from the other.
Why this service fits: Predictable, private connectivity supports steady ingestion.
Example: Logging collectors in GCP forward logs to a SIEM in OCI.

10) Latency-sensitive middleware (message bus) across clouds

Problem: Messaging performance is inconsistent over the internet.
Why this service fits: Private connectivity improves stability; still consider locality and failure domains.
Example: Event consumers in GCP subscribe to a message bus hosted in OCI.

6. Core Features

Feature availability and specific configuration options can vary by region pairing and account eligibility. Verify in official docs for your OCI region and Google Cloud region.

1) Private connectivity between OCI and Google Cloud

What it does: Provides a private network path for IP traffic between OCI and GCP.
Why it matters: Reduces exposure to public internet routing and congestion.
Practical benefit: More stable service-to-service traffic and improved security posture.
Caveats: “Private” does not automatically mean “encrypted.” Use TLS and/or overlay encryption when required.

2) BGP-based dynamic routing

What it does: Exchanges routes between OCI and GCP using BGP (via DRG and Cloud Router).
Why it matters: Reduces manual route updates and supports failover.
Practical benefit: Easier to scale networks and manage multiple subnets/VPCs/VCNs.
Caveats: Requires careful route advertisement control to avoid leaking routes or creating transitive routing unintentionally.

3) Redundancy design patterns (multi-link / multi-edge)

What it does: Supports high availability by using multiple connections/attachments and diverse routing paths (implementation details depend on the offering).
Why it matters: Single interconnect path is a reliability risk.
Practical benefit: Higher uptime and better maintenance tolerance.
Caveats: You must implement redundancy correctly (dual attachments, dual BGP sessions, route priorities).

4) Integration with OCI networking constructs (VCN, DRG, route tables)

What it does: Lets you attach multiple VCNs to a DRG and centrally manage routing.
Why it matters: Enables hub-and-spoke and shared services architectures on OCI.
Practical benefit: Cleaner governance and scalable network topology.
Caveats: DRG routing policies can be complex; document route intent and validate propagation.

5) Integration with Google Cloud networking constructs (VPC, Cloud Router)

What it does: Uses Cloud Router for BGP and route exchange with your VPC.
Why it matters: Standard Google Cloud model for dynamic routing to external networks.
Practical benefit: Familiar operations for GCP network admins; supports route-based changes.
Caveats: Route export/import policies and firewall rules must be set correctly.

6) Compartment/project governance and IAM control

What it does: Uses OCI IAM policies (compartments) and GCP IAM roles (projects) to control who can create/modify interconnect resources.
Why it matters: Networking changes are high-risk; IAM must be tight.
Practical benefit: Enables separation of duties and change control.
Caveats: Mis-scoped IAM is a common cause of outages or misconfigurations.

7) Observability hooks (metrics/logs at the network edge)

What it does: Enables monitoring of link status and routing health using each cloud’s monitoring stack.
Why it matters: Interconnect issues often appear as “app timeouts.”
Practical benefit: Faster detection of BGP down, route churn, or unexpected drops.
Caveats: Observability is split across two clouds; you need a combined operational view.

7. Architecture and How It Works

High-level service architecture

Oracle Interconnect for Google Cloud can be understood as: – OCI network edge (VCN + DRG) connected to – Interconnect infrastructure (private cross-cloud connectivity), connected to – Google Cloud network edge (Cloud Router + VPC)

Traffic between OCI and GCP flows via private routing, typically using BGP-learned routes.

Request/data/control flow (practical view)

Data plane: Application traffic between private IPs in OCI subnets and GCP subnets.
Control plane:
BGP sessions establish adjacency between OCI edge and Google Cloud Router.
Routes are advertised (e.g., OCI subnet CIDRs to GCP; GCP subnet CIDRs to OCI).
Each cloud updates route tables and forwarding behavior based on BGP and your explicit route policies.

Integrations with related services

On OCI: – Compute instances and load balancers inside VCNs consume the connectivity. – Network Security Groups (NSGs) control east-west traffic. – VCN DNS and private endpoints (where supported) can be part of the design.

On Google Cloud: – GCE and GKE workloads consume the connectivity. – Firewall rules control traffic. – Cloud DNS can integrate with private zones and forwarding policies.

Dependency services

OCI: VCN, DRG, routing tables, security constructs; underlying interconnect provisioning constructs.
GCP: VPC, Cloud Router, interconnect attachments/VLAN attachments, firewall rules.

Security/authentication model

IAM controls who can create/modify networking resources.
BGP session security: Depending on configuration, BGP may support MD5 authentication (verify exact options in your setup).
Traffic security:
Private routing reduces exposure.
Use TLS for application encryption.
For policy requirements, consider IPsec over the interconnect (overlay) if supported and necessary—verify in official docs and validate performance implications.

Networking model considerations

Non-overlapping CIDR is mandatory for clean routing.
Routing intent must be explicit:
Which subnets should be reachable cross-cloud?
Should this interconnect be transitive to on-prem?
MTU: Ensure consistent MTU assumptions to avoid fragmentation issues—verify recommended MTU values in the official docs.

Monitoring/logging/governance considerations

Monitor:
BGP session status
Route counts and unexpected route changes
Packet drops due to firewall rules/NSGs
Log:
OCI Audit logs for networking changes
GCP Admin Activity logs for route and router changes
Governance:
Tag/label interconnect resources with environment, owner, cost center
Use change management for routing updates

Simple architecture diagram (conceptual)

flowchart LR
  subgraph GCP[Google Cloud]
    VPC[VPC Subnet(s)]
    CR[Cloud Router (BGP)]
    VPC --> CR
  end

  subgraph LINK[Oracle Interconnect for Google Cloud]
    IC[Private Interconnect Path]
  end

  subgraph OCI[Oracle Cloud (OCI)]
    VCN[VCN Subnet(s)]
    DRG[Dynamic Routing Gateway (DRG)]
    VCN --> DRG
  end

  CR <-- BGP --> IC <-- BGP --> DRG
  VPC <-- Private IP Traffic --> VCN

Production-style architecture diagram (HA + segmentation)

flowchart TB
  subgraph GCP[Google Cloud]
    subgraph GCP_NET[Networking]
      VPC1[VPC: app-prod]
      VPC2[VPC: shared-services]
      CR1[Cloud Router A]
      CR2[Cloud Router B]
      VPC1 --> CR1
      VPC1 --> CR2
      VPC2 --> CR1
      VPC2 --> CR2
    end
    GKE[GKE / GCE Workloads]
    GKE --> VPC1
  end

  subgraph OCI[Oracle Cloud (OCI)]
    subgraph OCI_NET[Networking]
      DRG[DRG (hub)]
      VCN_APP[VCN: app-prod]
      VCN_SEC[VCN: security-inspection]
      VCN_DB[VCN: database]
      VCN_APP --> DRG
      VCN_SEC --> DRG
      VCN_DB --> DRG
      FW[Firewall / Inspection Appliances]
      VCN_SEC --> FW
    end
    DB[DB Workloads / Services]
    DB --> VCN_DB
  end

  subgraph INTERCONNECT[Oracle Interconnect for Google Cloud]
    IC1[Interconnect Path A]
    IC2[Interconnect Path B]
  end

  CR1 <-- BGP --> IC1 <-- BGP --> DRG
  CR2 <-- BGP --> IC2 <-- BGP --> DRG

  %% Policy routing concept
  VPC1 -. "Routes to OCI via Cloud Router" .-> CR1
  DRG -. "Route tables / distributions" .-> VCN_APP
  DRG -. "Inspection routing (optional)" .-> VCN_SEC
  DRG -. "DB subnets advertised to GCP" .-> VCN_DB

8. Prerequisites

Accounts/tenancy/project requirements

Oracle Cloud (OCI) tenancy with permissions to manage networking resources.
Google Cloud project with permissions to manage networking, Cloud Router, and interconnect-related resources.
Access to supported OCI region and supported Google Cloud region pairing for Oracle Interconnect for Google Cloud (verify availability in official docs).

Permissions / IAM roles

OCI IAM (examples; adjust to your compartment model): – Ability to manage VCN/DRG/network resources in a compartment (commonly via policies covering the virtual networking family). – Ability to create/attach route tables, subnets, NSGs, and DRG attachments.

Google Cloud IAM (typical roles; verify least-privilege needs): – Compute Network Admin (or more narrowly scoped roles) to manage VPC networks, routes, firewall rules. – Permissions to manage Cloud Router and Interconnect resources (exact roles depend on whether you use Cross-Cloud Interconnect or Cloud Interconnect constructs).

Billing requirements

Billing must be enabled in both OCI and Google Cloud.
Network connectivity services are typically billable; expect charges for:
Interconnect/attachment resources
Data transfer/egress on one or both sides
Test compute instances for validation

CLI/SDK/tools needed

OCI:
OCI Console access
Optional: OCI CLI
Google Cloud:
Google Cloud Console
Optional: gcloud via Cloud Shell or local install

Region availability

Oracle Interconnect for Google Cloud is not universally available in all regions.
Confirm:
Supported OCI region(s)
Supported Google Cloud region(s)
Supported region pairings and interconnect locations
Verify in official docs before committing to an architecture.

Quotas/limits (common ones to consider)

Number of DRGs and DRG attachments per tenancy/region
Number of route rules per route table
BGP route limits on Cloud Router / OCI DRG (route scale limits exist; verify current values in docs)
Interconnect attachment counts and bandwidth SKUs (verify)

Prerequisite services

OCI VCN and DRG must exist (or be created).
GCP VPC and Cloud Router must exist (or be created).
IP planning (non-overlapping CIDRs) must be completed.

9. Pricing / Cost

Do not treat this section as a quote. Prices vary by region, SKU, and sometimes contract terms. Always validate with the official pricing pages and your account team.

Pricing dimensions (what you pay for)

You typically pay for a combination of:

On Oracle Cloud (OCI) side (commonly aligned with FastConnect-like pricing dimensions): – Port/connection resources (where applicable) – Virtual circuit / attachment constructs (where applicable) – Data transfer (egress) from OCI to external networks (interconnect pricing may differ from public internet egress—verify current OCI price list)

On Google Cloud side: – Interconnect and VLAN attachment charges (varies by product: Dedicated Interconnect, Partner Interconnect, Cross-Cloud Interconnect—verify which one applies) – Data transfer (egress) from Google Cloud – Cloud Router-related costs (Cloud Router itself is typically billed by usage/attachment depending on Google’s current model—verify in Google’s pricing docs)

Free tier

Oracle Interconnect for Google Cloud is generally not a free-tier service.
You may use always-free compute resources for testing in OCI or GCP (subject to each cloud’s free tier rules), but the interconnect itself typically incurs costs.

Main cost drivers

Data egress volume: Usually the largest cost over time.
Provisioned bandwidth / attachment type: Higher capacity generally costs more.
Redundancy: Production HA patterns often require multiple attachments/circuits (increasing fixed monthly costs).
Cross-cloud traffic patterns: Chatty microservices can generate more cross-cloud traffic than expected.

Hidden or indirect costs

NAT gateways, load balancers, and firewalls you deploy for routing/inspection
Logging and monitoring ingestion/retention costs in both clouds
DNS architectures (private DNS resolvers, forwarding, etc.)
Operational staffing/time: network troubleshooting across two clouds

Network/data transfer implications

Understand the directionality:
OCI → GCP egress may be billed by OCI
GCP → OCI egress may be billed by GCP
In multicloud, teams sometimes underestimate east-west traffic across clouds. Track it early with flow logs/metrics.

How to optimize cost

Minimize cross-cloud chatter:
Keep latency-sensitive and chatty components in the same cloud where feasible.
Use caching and batching for cross-cloud calls.
Advertise only required routes to limit unintended traffic flows.
Use HA thoughtfully: two links is normal; more than that should be justified by SLOs.
Monitor egress daily/weekly and set budgets/alerts in both clouds.

Example low-cost starter estimate (model, not numbers)

A low-cost pilot typically includes: – 1 small OCI test VCN + 1 small GCP test VPC – 1 test VM in each cloud – Minimal set of advertised subnets (one /24 each) – Short test window
Costs will be driven primarily by: – Any fixed attachment/port charges – A small amount of data transfer for validation

Because rates vary, use official calculators: – OCI cost estimator: https://www.oracle.com/cloud/costestimator.html – Google Cloud pricing calculator: https://cloud.google.com/products/calculator

Example production cost considerations (what to model)

For production, model: – Two independent connectivity paths (HA) – Expected peak and average cross-cloud data transfer – Growth rate of traffic – Monitoring/logging retention – Backup/replication flows (often large and spiky)

Official pricing pages (start here)

OCI pricing (price list landing): https://www.oracle.com/cloud/price-list/
OCI networking documentation hub (for service-specific pricing references): https://docs.oracle.com/en-us/iaas/Content/home.htm
Google Cloud Interconnect pricing (verify correct product page for your setup): https://cloud.google.com/network-connectivity/docs/interconnect/pricing

10. Step-by-Step Hands-On Tutorial

Reality check: provisioning Oracle Interconnect for Google Cloud may require region pairing availability and may not be instant for all accounts. This lab is written to be executable if your account is eligible and the service is available in your regions. If you cannot complete the interconnect provisioning steps, you can still complete the network setup steps and learn the routing/security workflow.

Objective

Create private network connectivity between: – An OCI VCN subnet and – A Google Cloud VPC subnet
using Oracle Interconnect for Google Cloud, then validate end-to-end private IP reachability with ICMP and TCP tests.

Lab Overview

You will: 1. Create an OCI VCN, subnet, and DRG attachment. 2. Create a GCP VPC, subnet, and Cloud Router. 3. Provision/configure the Oracle Interconnect for Google Cloud connection (BGP). 4. Update routes and firewall/NSG rules on both sides. 5. Validate connectivity with test VMs. 6. Clean up all resources.

Step 1: Plan IP ranges and ASNs (do this first)

Choose non-overlapping RFC1918 ranges, for example: – OCI VCN: 10.10.0.0/16 – OCI test subnet: 10.10.10.0/24 – GCP VPC: 10.20.0.0/16 – GCP test subnet: 10.20.10.0/24

Choose BGP ASNs – OCI side: you will use a DRG ASN (or BGP ASN) depending on OCI configuration. – GCP side: Cloud Router ASN (private ASN recommended).

ASNs must not conflict with existing BGP peers in your network.
Expected outcome: You have documented CIDRs and ASNs and confirmed they do not overlap.

Step 2: Create the OCI network (VCN + subnet)

Option A: OCI Console (beginner-friendly)

In OCI Console, select your region.
Go to Networking → Virtual cloud networks.
Create a VCN with: – VCN CIDR: 10.10.0.0/16 – Create at least one subnet:
- Subnet CIDR: 10.10.10.0/24
- Choose Private subnet if you want all tests to remain private (recommended).
Create or select a Network Security Group (NSG) for your test VM.

Option B: OCI CLI (example)

If you prefer CLI, verify syntax in OCI CLI docs and adapt compartment OCIDs:

oci network vcn create \
  --compartment-id <COMPARTMENT_OCID> \
  --display-name oci-vcn-multicloud-lab \
  --cidr-block 10.10.0.0/16

Expected outcome: OCI VCN and a subnet exist.

Step 3: Create an OCI DRG and attach it to the VCN

In OCI Console, go to Networking → Dynamic Routing Gateways.
Create a DRG (name it like drg-oci-gcp-lab).
Attach the DRG to your VCN.

Then configure routing: – In the subnet route table (or DRG route table model depending on OCI routing mode), ensure routes exist so that traffic destined to the GCP CIDR (10.20.0.0/16) is routed to the DRG.

Expected outcome: DRG exists and is attached; OCI routing has a path toward GCP via DRG.

Step 4: Create the Google Cloud network (VPC + subnet)

In Google Cloud Console: 1. Select your project. 2. Go to VPC network → VPC networks → Create VPC network. 3. Create: – Name: gcp-vpc-multicloud-lab – Subnet: 10.20.10.0/24 in your chosen region

Create firewall rules to allow test traffic: – Allow ICMP from 10.10.0.0/16 – Allow TCP:22 (SSH) from your admin IP (for management) – Optionally allow a test TCP port (e.g., 80/443) between subnets as needed

Using gcloud (optional example):

gcloud compute firewall-rules create allow-icmp-from-oci \
  --network gcp-vpc-multicloud-lab \
  --allow icmp \
  --source-ranges 10.10.0.0/16

Expected outcome: GCP VPC and subnet exist; firewall rules allow basic validation traffic.

Step 5: Create a Cloud Router on Google Cloud

Go to Network Connectivity (or Hybrid Connectivity) → Cloud Routers (navigation can vary).
Create a Cloud Router: – Name: cr-oci-interconnect-lab – Region: same as your VPC subnet region – ASN: choose a private ASN (e.g., 64512). Use your planned value.

Expected outcome: Cloud Router exists and is ready for interconnect/VLAN attachments.

Step 6: Provision Oracle Interconnect for Google Cloud connectivity

This is the step that depends most on: – region pairing availability, – account eligibility, – and current provisioning workflow.

At a high level, you will create: – On OCI: an interconnect-related attachment/virtual circuit associated with your DRG – On GCP: an interconnect attachment (VLAN attachment) associated with your Cloud Router – Establish BGP sessions and exchange routes

Because the exact UI labels and required identifiers can vary, follow the official setup guide for your region pairing and ensure you capture: – BGP peer IPs (link-local or allocated addresses, depending on model) – BGP ASN values on both sides – Redundancy requirements (usually at least two BGP sessions)

OCI side (conceptual): – Create the Oracle Interconnect for Google Cloud connection/attachment and associate it with your DRG. – Configure route import/export policies (DRG route tables) so only intended OCI subnets are advertised.

GCP side (conceptual): – Create VLAN attachment(s) and associate them with Cloud Router. – Configure BGP peers and ensure routes from OCI are learned.

Expected outcome: – BGP session(s) show Established (or equivalent) on both clouds. – Each side learns the other side’s subnet routes (OCI learns 10.20.10.0/24; GCP learns 10.10.10.0/24), subject to your route policies.

Step 7: Create one test VM in each cloud

OCI test VM

Create a small compute instance in subnet 10.10.10.0/24.
Place it in an NSG that allows:
ICMP from 10.20.0.0/16
SSH from your admin IP (optional; recommended for troubleshooting)

GCP test VM

Create a small e2-micro-class VM (or smallest appropriate) in subnet 10.20.10.0/24.
Ensure firewall rules allow ICMP from OCI subnet range.

Expected outcome: You have: – OCI VM private IP (e.g., 10.10.10.10) – GCP VM private IP (e.g., 10.20.10.10)

Step 8: Confirm routes on both sides

On Google Cloud

Check that Cloud Router learned OCI routes and that VPC route tables include paths toward OCI.

Using gcloud (example; adjust for your environment):

gcloud compute routers get-status cr-oci-interconnect-lab --region <REGION>

Look for: – BGP peer status = Established – Learned routes include 10.10.10.0/24 or 10.10.0.0/16 (depending on what you advertised)

On OCI

Confirm DRG route tables and route distributions show GCP routes are imported and VCN route tables send GCP CIDR to DRG.

OCI has multiple DRG routing models; verify using the OCI Console DRG route tables view.

Expected outcome: Each cloud has a route to the other cloud’s subnet CIDR via the interconnect.

Step 9: Validate end-to-end connectivity

From the GCP VM, ping the OCI VM private IP:

ping -c 4 10.10.10.10

From the OCI VM, ping the GCP VM private IP:

ping -c 4 10.20.10.10

Optional TCP test (from GCP VM to OCI VM, if you enable SSH/HTTP accordingly):

nc -vz 10.10.10.10 22

Traceroute (useful to confirm private path):

traceroute 10.10.10.10

Expected outcome: – ICMP ping succeeds both directions (if allowed by firewall/NSG rules). – TCP checks succeed for allowed ports. – Traceroute shows a small number of hops (exact hops depend on implementation; do not expect public internet hops).

Validation

Use this checklist:

BGP peers: Established on GCP Cloud Router and OCI DRG side.
Routes:
GCP has routes to 10.10.0.0/16 (or subnet routes) via interconnect.
OCI has routes to 10.20.0.0/16 (or subnet routes) via DRG.
Security:
GCP firewall allows ICMP (and test ports) from OCI CIDR.
OCI NSG/Security List allows ICMP (and test ports) from GCP CIDR.
Connectivity:
Ping works both ways.
Optional app test (HTTP/DB) works across clouds.

Troubleshooting

1) BGP session is down

Common causes: – ASN mismatch between peer configuration – Incorrect peer IPs or link-local addressing mismatch – Missing VLAN attachment association with Cloud Router – Route policy denies BGP peer or required routes

Fix: – Re-check BGP peer parameters on both sides against the official setup guide for your interconnect model.

2) BGP is up, but no routes learned

Common causes: – You are not exporting any prefixes (advertisement missing) – Import/export policy filters are too strict – DRG route distribution not configured as expected

Fix: – Explicitly advertise the intended subnet CIDRs on both sides. – Verify DRG route table associations and route distribution statements in OCI.

3) Routes exist, but ping fails

Common causes: – Firewall rules / NSGs block ICMP – OS firewall (iptables/ufw) blocks ICMP – Asymmetric routing due to conflicting routes

Fix: – Temporarily allow ICMP between the two CIDR ranges. – Confirm both directions have routes and next-hops correct.

4) Overlapping CIDR blocks

Symptom: – Routes are ignored or traffic blackholes.

Fix: – Re-IP one side. Overlapping RFC1918 ranges are a frequent multicloud blocker.

5) DNS issues

Symptom: – IP connectivity works, but service name resolution fails.

Fix: – Use private DNS zones and forwarding rules appropriate for each cloud. – Validate resolvers and search domains; consider conditional forwarding.

Cleanup

In reverse order, delete: 1. Test VMs in OCI and GCP 2. GCP firewall rules created for the lab (if not needed) 3. GCP VLAN attachments / interconnect resources 4. OCI interconnect attachment/virtual circuit resources 5. DRG attachment to VCN and DRG (if dedicated to the lab) 6. OCI VCN and subnets 7. GCP VPC and subnet (if dedicated to the lab)

Expected outcome: No ongoing interconnect attachments or test compute resources remain, minimizing cost.

11. Best Practices

Architecture best practices

Design with clear routing intent:
Which networks are reachable cross-cloud?
Which must remain isolated?
Prefer hub-and-spoke:
OCI DRG as hub for multiple VCNs
GCP shared VPC patterns (if applicable)
Avoid accidental transitive routing:
If OCI is connected to on-prem and GCP, be explicit about whether GCP can reach on-prem via OCI (and vice versa).

IAM/security best practices

Least privilege:
Separate “network provisioning” from “app deployment.”
Use compartments/projects per environment (dev/test/prod).
Require change approval for routing and firewall policy changes.

Cost best practices

Track and alert on egress in both clouds.
Minimize cross-cloud “chatty” calls; keep high-volume internal calls intra-cloud when possible.
Use budgets and anomaly detection where available.

Performance best practices

Keep workloads in paired regions with lowest latency.
Validate MTU and avoid fragmentation issues (verify recommended MTU).
Batch data transfers; use compression where appropriate.

Reliability best practices

Use redundant attachments/paths and test failover.
Document failover behavior:
Which routes are preferred?
What happens during maintenance?
Run periodic game days: disable one BGP peer and verify traffic continues.

Operations best practices

Centralize observability:
BGP status dashboards
Route count dashboards
Cross-cloud latency probes
Implement runbooks:
“BGP down”
“Routes missing”
“Packet loss”
Standardize tags/labels:
env, owner, cost-center, service, ticket

Governance/tagging/naming best practices

Use consistent names:
drg-prod-gcp-interconnect
cr-prod-oci-interconnect
Tag all networking resources; missing tags often lead to orphaned, billable resources.

12. Security Considerations

Identity and access model

OCI: IAM policies determine who can manage DRGs, VCNs, route tables, and interconnect constructs.
GCP: IAM roles determine who can manage VPC, Cloud Router, firewall, interconnect attachments.

Security recommendation: – Separate duties: – Network admins manage routing/interconnect – App teams manage compute and application configuration

Encryption

Interconnect provides private connectivity, but encryption-in-transit may still be required:
Use TLS for app protocols
Consider IPsec overlay when mandated (verify performance and support)

Network exposure

Treat cross-cloud as a high-trust boundary only if your policy allows it.
Use segmentation:
Only advertise required routes
Apply NSGs/firewalls tightly

Secrets handling

Don’t hardcode credentials in cross-cloud scripts.
Use each cloud’s secret manager:
OCI Vault
Google Secret Manager

Audit/logging

OCI Audit: track networking changes (route tables, DRG changes).
GCP Cloud Audit Logs: track router, interconnect, and firewall changes.
Centralize logs into your SIEM with retention policies.

Compliance considerations

Confirm data residency and region pairing constraints.
Validate that cross-cloud data flows meet regulatory requirements (HIPAA, PCI, etc.)—this is architecture and governance work, not just networking.

Common security mistakes

Advertising broad CIDRs (10.0.0.0/8) by accident
Allowing 0.0.0.0/0 in firewall rules for troubleshooting and forgetting to revert
Creating transitive routing between on-prem and the other cloud unintentionally
Assuming “private” means “encrypted” and skipping TLS

Secure deployment recommendations

Advertise only specific subnet prefixes.
Use layered security:
NSGs + firewalls + application auth
Use continuous validation:
Periodic route audits
Connectivity tests from controlled probes

13. Limitations and Gotchas

Limits and behaviors vary; verify exact values in official docs.

Known limitations / constraints

Region pairing availability: Not all OCI regions connect to all GCP regions.
Provisioning constraints: Some setups require coordination and may not be instantly available for all accounts.
Route scale limits: BGP route limits exist on routers; do not assume unlimited prefixes.

Quotas

OCI quotas on DRGs, attachments, route rules.
GCP quotas on interconnect attachments, Cloud Routers, learned routes.

Regional constraints

Latency and throughput depend on the physical interconnect path.
Disaster recovery design must consider if the interconnect is region-pair specific.

Pricing surprises

Egress charges in both clouds can grow quickly.
Redundant attachments cost more but are often required for production.

Compatibility issues

Overlapping RFC1918 CIDRs break routing.
MTU mismatches can cause hard-to-debug performance issues.

Operational gotchas

Split ownership: Network teams need access/visibility in both clouds.
Troubleshooting is two-sided:
A route missing in GCP can look like an OCI problem (and vice versa).
Asymmetric routing:
Can occur with incorrect route priorities or propagation settings.

Migration challenges

Existing environments often have overlapping CIDRs.
Legacy apps may depend on hard-coded IPs or DNS assumptions.

Vendor-specific nuances

OCI DRG routing and route distribution is powerful but can be complex.
GCP Cloud Router behavior is BGP-centric; you must understand import/export and learned routes.

14. Comparison with Alternatives

Alternatives to consider

IPsec VPN between OCI and GCP (over public internet)
Self-managed carrier connectivity via colocation and third-party routing
OCI FastConnect to a colocation + GCP Dedicated/Partner Interconnect (DIY)
Public internet connectivity with strict TLS and WAFs (not ideal for private east-west)

Comparison table

Option	Best For	Strengths	Weaknesses	When to Choose
Oracle Interconnect for Google Cloud	Production multicloud OCI↔GCP with private routing	Private connectivity, BGP routing, predictable performance	Region pairing constraints; provisioning complexity; cost	When you need stable private connectivity between OCI and GCP
IPsec VPN (OCI↔GCP)	Dev/test, low-throughput production, quick setup	Fast to deploy; widely available	Internet variability; throughput limits; more jitter	When interconnect is unavailable or not justified yet
DIY colocation (FastConnect + Interconnect)	Large enterprises with network teams and carrier contracts	Full control over topology	Operational complexity; longer lead time	When you need custom global connectivity beyond supported pairings
Public internet + TLS	Public-facing APIs only	Lowest setup complexity	Not private; depends on internet; security posture depends on app controls	When traffic is inherently public and not east-west private networking

15. Real-World Example

Enterprise example: regulated financial services multicloud

Problem: A bank runs customer-facing apps on Google Cloud (GKE) but needs Oracle database services and certain compliance tooling in Oracle Cloud. Internet VPN latency variability causes timeouts and operational incidents.
Proposed architecture:
GCP: GKE in a dedicated VPC
OCI: Database VCN + security inspection VCN
Oracle Interconnect for Google Cloud with redundant BGP sessions
Tight route advertisement: only app and DB subnets
Centralized logging: both clouds feed a SIEM
Why this service was chosen:
Private connectivity and predictable latency for transactional workloads
BGP for scalable routing across multiple subnets
Stronger security boundary than internet-based VPN alone
Expected outcomes:
Reduced cross-cloud API latency and fewer timeouts
Improved operational stability (fewer routing incidents)
Clear audit trail and governance for network changes

Startup/small-team example: SaaS with split compute and data

Problem: A startup uses Google Cloud for rapid app iteration and managed services, but relies on Oracle Cloud for Oracle-compatible database capabilities and cost/performance characteristics. VPN throughput is too low for nightly sync jobs.
Proposed architecture:
One OCI VCN hosting database and a small bastion/admin subnet
One GCP VPC hosting application services
Oracle Interconnect for Google Cloud for private data sync and app-to-db traffic
Budget alerts on both clouds to track egress
Why this service was chosen:
Improved throughput and reliability without building a DIY colocation network
Keeps sensitive data flows off the public internet path
Expected outcomes:
Nightly jobs complete within window
Better user latency for app-to-db calls
Simplified networking compared to custom carrier approaches

16. FAQ

Is Oracle Interconnect for Google Cloud the same as a VPN?
No. VPN typically runs over the public internet with encryption. Oracle Interconnect for Google Cloud is designed for private connectivity using interconnect infrastructure and BGP routing.
Does “private interconnect” mean traffic is encrypted?
Not necessarily. Private routing reduces exposure to the public internet, but you should still use TLS and consider overlay encryption if required by policy.
Do I need BGP knowledge to use this service?
Yes, at least basic BGP and routing knowledge is strongly recommended. Your network team should own route advertisement and failover design.
Which regions are supported?
Support is based on OCI↔GCP region pairings. Check the official Oracle and Google Cloud documentation for the current list.
How long does provisioning take?
It depends on region pairing and workflow. Some components can be created quickly, while others may require additional provisioning steps. Verify in official docs.
Can I connect multiple OCI VCNs to one Google Cloud VPC?
Often yes using DRG hub patterns and careful route policies, but design complexity increases. Validate route limits and governance.
Can I connect multiple GCP VPCs to OCI?
Yes, typically via Cloud Router and VPC design patterns (including Shared VPC). Ensure route advertisement and firewall rules are correct.
What are the most common causes of outages?
Route leaks, accidental broad advertisements, firewall/NSG changes, and BGP session misconfiguration.
How do I prevent transitive routing (GCP ↔ OCI ↔ on-prem)?
Use strict route import/export filters and DRG route tables. Only advertise intended prefixes.
Is this service appropriate for dev/test?
It can be, but cost and setup complexity may make VPN a better fit for ephemeral environments.
How do I monitor connectivity health?
Monitor BGP session status, learned route counts, and run synthetic probes (ping/TCP) between dedicated test endpoints.
Can I use private DNS across clouds?
Yes, but DNS requires explicit design (forwarding, conditional zones, resolvers). Do not assume private IP connectivity solves DNS automatically.
What about MTU and jumbo frames?
MTU mismatches can cause fragmentation/performance issues. Follow official recommendations and test with realistic payload sizes.
Do I need overlapping security controls in both clouds?
Yes. Enforce least privilege at multiple layers: route advertisements, firewall/NSG rules, and application authentication.
How do I estimate cost before production?
Model fixed connectivity charges and expected data egress in both directions. Use OCI and Google pricing calculators and add monitoring/logging costs.

17. Top Online Resources to Learn Oracle Interconnect for Google Cloud

Resource Type	Name	Why It Is Useful
Official documentation	OCI Documentation (Networking) – https://docs.oracle.com/en-us/iaas/Content/home.htm	Starting point for OCI networking concepts (VCN, DRG, routing, FastConnect patterns). Use it to find the latest interconnect-specific guide.
Official documentation	OCI FastConnect docs – https://docs.oracle.com/en-us/iaas/Content/Network/Concepts/fastconnect.htm	Oracle Interconnect for Google Cloud commonly aligns with private connectivity patterns; FastConnect concepts help understand private circuits and DRG routing.
Official pricing	OCI Price List – https://www.oracle.com/cloud/price-list/	Official source for OCI networking pricing dimensions and regional price lists.
Official calculator	OCI Cost Estimator – https://www.oracle.com/cloud/costestimator.html	Estimate OCI-side costs (compute, networking, egress).
Official documentation	Google Cloud Interconnect overview – https://cloud.google.com/network-connectivity/docs/interconnect	Understand Google’s interconnect constructs and how Cloud Router interacts with them.
Official pricing	Google Cloud Interconnect pricing – https://cloud.google.com/network-connectivity/docs/interconnect/pricing	Official pricing model for interconnect and attachments.
Official documentation	Google Cloud Router docs – https://cloud.google.com/network-connectivity/docs/router	Essential for BGP configuration, learned routes, and troubleshooting on GCP.
Architecture references	OCI Architecture Center – https://docs.oracle.com/en/solutions/	Reference architectures and design patterns (search within for multicloud networking).
Hands-on labs	OCI Hands-on Labs (official GitHub) – https://oracle-labs.github.io/	Practical labs for OCI networking and related services; useful for foundational skills used in interconnect setups.
Training (official)	Google Cloud Training – https://cloud.google.com/training	Foundational and advanced networking courses relevant to Cloud Router and Interconnect.

18. Training and Certification Providers

Institute	Suitable Audience	Likely Learning Focus	Mode	Website URL
DevOpsSchool.com	DevOps engineers, SREs, cloud engineers	DevOps + cloud operations; may include multicloud connectivity concepts	Check website	https://www.devopsschool.com/
ScmGalaxy.com	Beginners to intermediate engineers	DevOps fundamentals, tooling, CI/CD; complementary skills for multicloud operations	Check website	https://www.scmgalaxy.com/
CLoudOpsNow.in	Cloud ops and platform teams	Cloud operations practices, monitoring, cost awareness	Check website	https://cloudopsnow.in/
SreSchool.com	SREs and reliability-focused engineers	Reliability engineering, observability, incident response	Check website	https://sreschool.com/
AiOpsSchool.com	Ops teams adopting AIOps	AIOps concepts, event correlation, automated remediation	Check website	https://aiopsschool.com/

19. Top Trainers

Platform/Site	Likely Specialization	Suitable Audience	Website URL
RajeshKumar.xyz	DevOps/cloud training content (verify offerings)	Individuals and teams seeking guided learning	https://rajeshkumar.xyz/
devopstrainer.in	DevOps training (verify course catalog)	Beginners to advanced DevOps practitioners	https://devopstrainer.in/
devopsfreelancer.com	DevOps consulting/training services marketplace style (verify)	Teams needing short-term expertise	https://devopsfreelancer.com/
devopssupport.in	DevOps support and training (verify services)	Ops teams needing practical support	https://devopssupport.in/

20. Top Consulting Companies

Company Name	Likely Service Area	Where They May Help	Consulting Use Case Examples	Website URL
cotocus.com	Cloud/DevOps consulting (verify specialization)	Architecture, automation, cloud operations	Multicloud network design reviews; CI/CD integration for multicloud apps	https://cotocus.com/
DevOpsSchool.com	DevOps and cloud consulting/training	Skills enablement, implementation support	Building runbooks/observability for interconnect operations; platform team coaching	https://www.devopsschool.com/
DEVOPSCONSULTING.IN	DevOps consulting (verify offerings)	DevOps transformation and support	Network automation, IaC pipelines, operational readiness assessments	https://devopsconsulting.in/

21. Career and Learning Roadmap

What to learn before this service

Networking fundamentals:
CIDR, subnets, routing tables
Firewalls and security groups
BGP basics:
ASN, neighbors, route advertisement
route filtering, MED/local preference concepts (as applicable)
OCI fundamentals:
VCNs, subnets, NSGs
DRG concepts and routing
Google Cloud fundamentals:
VPC, firewall rules
Cloud Router and dynamic routing

What to learn after this service

Advanced multicloud network patterns:
Segmentation, inspection, and zero trust
Multi-region DR and failover testing
Infrastructure as Code:
Terraform for OCI and Google Cloud
Observability:
SLOs, synthetic probes, combined dashboards
Security:
Threat modeling for multicloud
Key management and secret rotation

Job roles that use it

Cloud Network Engineer
Cloud Solutions Architect
Platform Engineer
SRE / Reliability Engineer (network-heavy)
DevOps Engineer (in multicloud orgs)
Security Engineer (network segmentation and controls)

Certification path (if available)

OCI certifications (networking-focused) and Google Cloud networking certifications are both relevant.
Specific certifications for Oracle Interconnect for Google Cloud may not exist as standalone; verify current certification catalogs:
OCI training/certifications: https://education.oracle.com/
Google Cloud certifications: https://cloud.google.com/learn/certification

Project ideas for practice

Build a hub-and-spoke OCI DRG network and simulate route propagation rules.
Create a dual-cloud connectivity runbook: BGP down, route leak, firewall block.
Implement synthetic probes that measure latency and packet loss across clouds and alert on thresholds.
Design a multicloud DNS solution with private zones and conditional forwarding.

22. Glossary

OCI (Oracle Cloud Infrastructure): Oracle Cloud platform providing compute, networking, storage, and managed services.
Google Cloud (GCP): Google’s cloud platform including VPC networking and Cloud Router.
Multicloud: Using two or more cloud providers in a single architecture.
VCN (Virtual Cloud Network): OCI private network construct.
VPC (Virtual Private Cloud): Google Cloud private network construct.
DRG (Dynamic Routing Gateway): OCI virtual router for connecting VCNs to external networks (including other clouds).
Cloud Router: Google Cloud managed BGP router for dynamic route exchange.
BGP (Border Gateway Protocol): Routing protocol used to exchange IP routes between networks.
ASN (Autonomous System Number): Identifier used in BGP to represent a routing domain.
CIDR: Notation for IP ranges (e.g., 10.10.0.0/16).
Route advertisement: The prefixes a router announces to a BGP peer.
Learned routes: Routes received from a BGP peer.
NSG (Network Security Group): OCI virtual firewall construct applied to VNICs.
Firewall rules (GCP): VPC firewall policies controlling traffic to/from instances.
Egress: Outbound data transfer from a cloud network (often billed).
Transitive routing: Using one network as a pass-through to reach another network (can be accidental and risky).

23. Summary

Oracle Interconnect for Google Cloud (Oracle Cloud) is a multicloud private connectivity service that enables private, BGP-routed networking between OCI and Google Cloud. It matters because it gives architects and operators a more predictable, governable alternative to internet VPN for cross-cloud traffic—especially for production systems where latency, throughput, and route control are critical.

From a cost perspective, the biggest drivers are data egress and the number/type of interconnect attachments needed for HA. From a security perspective, the key points are strict route advertisement control, layered firewall/NSG policies, and remembering that private connectivity does not automatically equal encryption—use TLS (and overlay encryption when required).

Use Oracle Interconnect for Google Cloud when you have supported region pairings and a real need for private, stable cross-cloud networking. Your next learning step should be to master OCI DRG routing and Google Cloud Router BGP operations, then implement an operational playbook for monitoring, troubleshooting, and cost control across both clouds.

rajeshkumar

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