Hands-on VPC Peering Configuration on GCP

Introduction

When it comes to talk about GCP networking, we must know what Virtual Private Cloud (VPC) is. According to GCP document, a Virtual Private Cloud (VPC) network is a virtual version of a physical network, such as a data center network. It provides connectivity for your Compute Engine virtual machine (VM) instances, Google Kubernetes Engine (GKE) clusters, App Engine flexible environment instances, and other resources in your project. GCP has an amazing video talking about VPC and all of you are really recommended to watch. From my point of view, VPC is nothing but just a “landing”. Our VM servers are just like a “building”. What we have to do is to plan which area should place which buildings. For example, we could classify our “area” by function. We could group our application servers into one VPC network, web servers into another one VPC network and database servers into another one VPC network. Of course, you could have your own design, it depends on your needs. For best practices, please take a look on this Google document. In fact, similar VPC service also appears on AWS and Azure those popular public cloud.

VPC Network Peering

In real situation, the networking is quite complicated especially in some big compines. For instance, one big company could own a few small companies. Then they may have different subnets and communicate with each others through internal IP. First of all, you may say you could still access the instances through external IP…