Azure vs GCP: Cloud Networking Architecture Comparison
| Concept | Azure | Google Cloud |
|---|---|---|
| Network Scope | Virtual Network (VNet) per region; global peering for cross-region connectivity. | Virtual Private Cloud (VPC) is global; subnets are regional. |
| Routing | System routes + user-defined routes per subnet; support for Virtual WAN. | Global routing table with route priorities; custom static/dynamic routes per VPC. |
| Firewalls | Network Security Groups (stateful L4), Azure Firewall for managed L7 inspection. | Firewall rules at VPC level (stateful L3/L4), Cloud Armor for L7 protection. |
| Private Service Access | Private Link/Endpoint for PaaS services; Service Endpoints for VNet integration. | Private Service Connect, VPC Service Controls for data exfiltration protection. |
| Hybrid Connectivity | VPN Gateway, ExpressRoute, Virtual WAN hub/spoke. | Cloud VPN, Cloud Interconnect (Dedicated/Partner), Network Connectivity Center. |
Design Considerations
- Address Planning: Azure reserves /29 per subnet and supports IPv6 dual-stack. GCP offers automatic subnet creation or custom subnet mode with global RFC 1918 planning.
- Multi-Region Architectures: Azure requires VNet peering or Virtual WAN to span regions; GCP’s global VPC simplifies multi-region traffic but demands firewall hygiene.
- Segmentation: Azure uses NSGs + Application Security Groups for microsegmentation. GCP uses hierarchical firewall policies, IAM bindings, and Shared VPC service projects.
- Load Balancing: Azure splits between regional (Standard/Internal) and global (Traffic Manager/Front Door). GCP offers global anycast load balancing for L4/L7 with a unified control plane.
When to Choose Which
- Azure Strengths: Tight integration with Microsoft identity (Entra ID), Virtual WAN for large corporate networks, and rich hybrid connectivity models with ExpressRoute.
- GCP Strengths: Global VPC reduces network sprawl, native integration with Anthos/GKE, and granular IAM-based control for networking resources.
Best Practices
- Implement Infrastructure as Code (Bicep/Terraform) to manage routes, firewalls, and peering consistently.
- Enable flow logs (Azure NSG Flow Logs, GCP VPC Flow Logs) for observability and threat detection.
- In regulated environments, couple network segmentation with policy tools (Azure Policy, GCP Organization Policy + VPC Service Controls).