Hybrid Cloud - Setting up Site-to-Site IPSec VPN Connectivity between Oracle and Google Cloud

Introduction

As enterprises move to cloud there is a need to connect cloud-native applications with on-premise legacy systems. Multi-Cloud architectures allow you to build solutions spanning more than one public cloud by combining best of breed capabilities creating an increasing need for interconnecting these clouds. For example, you may want to use the Google App Engine to deploy your app but for your backend prefer Oracle ATP database hosted on Oracle Cloud. 

Each public cloud provides multiple connectivity options from dedicated high speed interconnect to using VPN based technologies to connect to on-premise using IPSec based connections that use public internet but provide secure connectivity.

Oracle OCI offers service called VPN Connect for site-to-site connectivity between an on-premise network with OCI VCN using VPN based on the IPSec protocol. 

In this blog, I will outline steps for configuring VPN between Oracle OCI Private Subnet with Google GCP VPC. VPN using IPSec is a cost-effective way of connecting these networks over public internet obviating no need for expensive lease lines and such. Steps outlined here also apply if you are trying to connect your on-premise network with either of these two cloud service providers. 

Note that I will focus on Site-to-Site connectivity based on IPSec protocol and use out-of-the-box functionality for VPN provided by these two cloud providers. You can also use other VPN implementations such as open-source Strongswan and Libreswan. 

Oracle OCI Cloud - Connecting a Private VM from a Public Bastion Host

Introduction

The following outlines the configuration for connecting a backend private instance though a public instance in the same VCN but different subnets. 

This post talks about the necessary configurations of Router, Firewall, and builds a complete end-end example. 

High-Level Steps

• Create VCN and two subnets (one public, one private)
• Create VMs - one in each subnet
• Configure Router
• Configure Firewall
• Test and Verify
• Access to OCI Instance

Note this is part one of the multi-part series wherein we extend this example and do necessary configuration on OCI and try to establish Hybrid Connectivity to a private instance on Google Cloud (GCP) using VPN.

Pre-requisites

• User with necessary privileges to create VCN, VM and configure networking
• SSH key (public and private key pair) - Basic knowledge of networking - CIDR, Routers, Firewall, etc..