Optimizing Network Architecture for Large Enterprises in Google Cloud

Introduction

In the era of cloud computing, selecting the right network architecture is critical for large enterprises to ensure scalability, security, and cost-efficiency while balancing centralized management and individual project isolation. In this blog, we will explore the decision-making process between choosing a Shared Virtual Private Cloud (VPC) and a Hub-and-Spoke Network Topology for our organization’s cloud environment. Our aim is to create a secure and high-performing Google Cloud infrastructure that aligns with our specific needs and requirements.

Understanding the Issue: Shared VPC vs. Hub-and-Spoke Topology

As a large enterprise moving to Google Cloud, we faced the challenge of determining the most suitable network architecture for our organization. I have considered the Shared VPC model, where all workloads share the same network resources, and the Hub-and-Spoke topology, consisting of a central hub VPC connected to multiple spoke VPCs.

Assumptions

Before making our decision, I established some critical assumptions:

1. Service Compatibility: All current and planned applications and services within the chosen architecture should be compatible with both Shared VPC and hub-and-spoke models, or adaptions can be made as needed.
2. Interoperability Needs: The chosen architecture should seamlessly interact with existing systems, considering interoperability in the evaluation.

Analyzing the Alternatives

1. Shared VPC Network for Each Environment: The Shared VPC model can provide some advantages, such as simplified resource management and centralized connectivity. However, it introduces challenges related to security, performance, scalability, and higher costs due to shared resources.

2. Hub-and-Spoke Topology with Centralized Appliances: The Hub-and-Spoke topology offers improved security and performance, allowing isolation and segmentation between different projects or business units. However, introducing centralized appliances may add complexity to the implementation.

3. Hub-and-Spoke Topology without Appliances (Recommended): After careful evaluation, I chose Option 2, the Hub-and-Spoke topology without centralized appliances, as our preferred network architecture. This model offers clear isolation and segmentation between projects, enhancing security while ensuring flexibility with unique configurations for various needs.

Justification for the Decision

The chosen Hub-and-Spoke Topology without Appliances aligns perfectly with our organization’s goals and requirements. Here are some key reasons behind our decision:

1. Enhanced Security: With separate spoke VPCs, each workload maintains individual security controls, isolating potential security breaches and safeguarding sensitive data.

2. Improved Performance: Spoke VPCs provide dedicated network bandwidth for individual workloads, reducing latency and ensuring smooth operations for bandwidth-intensive tasks.

3. Simplified Management: The hub serves as a central point for shared resources, optimizing resource utilization and easing management efforts.

4. Flexibility and Scalability: Adding new spokes as needed allows for seamless scaling and accommodating future growth without disrupting existing configurations.

5. Cost Optimization: Centralizing shared services and resources in the hub VPC can lead to cost efficiencies through optimized resource usage.

Network Diagram:

The preceding diagram shows the following:

• A production environment which includes a hub VPC network and multiple spoke VPC networks that contain the workloads.
• The spoke VPC networks are connected with the hub VPC network using VPC network peering.
• Connectivity to on-premises locations passes through Cloud Interconnect connections in the hub VPC network.
• On-premises networks are connected through the Cloud Interconnect instances using separate VLAN attachments.
• The development environment has the same VPC structure as the production environment.

In this design, workloads cannot communicate with each other. However, if specific workloads must communicate with each other, you can set up direct peering between the spoke networks using VPC network peering.

This network design is often used in environments where teams act autonomously and there is no centralized control over firewall and routing rules. However, the scale of this design is limited by the following:

• The limit on VPC Network Peering connections from a single VPC network
• Peering group limits such as the maximum number of forwarding rules for Internal TCP/UDP Load Balancing for each peering group

Conclusion

Choosing the right network architecture for large enterprises in Google Cloud requires careful evaluation of available options and organizational requirements. By opting for the Hub-and-Spoke Topology without Appliances, we have crafted a secure, scalable, and cost-efficient network infrastructure tailored to our unique needs. With this architectural decision, we can confidently embark on our cloud journey, harnessing the power of Google Cloud to drive innovation and business growth.

By implementing the recommended network design, we have laid the groundwork for a strong, secure, and high-performing Google Cloud Landing Zone, poised to meet our organization’s evolving demands and objectives.