AWS Cloud WAN: The Future of Networking Centrally Managed

Vision for the Future of Networking: Centrally Managed:
AWS Cloud WAN is rapidly changing the future of enterprise networking by providing a fully managed, cloud-native platform that unifies on-premises, branch, and cloud network management. As organizations increasingly adopt distributed and cloud-first architectures, Cloud WAN addresses the rising complexity with simplified, scalable, and programmable networking solutions.

Key Features Driving the Future

Centralized Global Management: Cloud WAN offers a single dashboard and a policy-driven approach for configuring, deploying, and managing global networks. IT teams can define intent in a central policy, and AWS enforces these controls across multiple regions, accounts, and environments.

Integrated Security & Network Segmentation: Security policies and network segmentation (similar to VRFs) are native to Cloud WAN. This allows isolation of sensitive workloads and the enforcement of compliance across a global infrastructure without the operational burden of manual configurations.

Native Hybrid and SD-WAN Support: It seamlessly integrates traditional WAN, SD-WAN, and public cloud, providing flexibility to choose the optimal path—VPN, SD-WAN, or direct—between sites and clouds. Innovators like Versa and Cisco already peer SD-WAN appliances natively with Cloud WAN, eliminating the historical overhead and complexity of VPN tunneling

Automation & Reduced Complexity: Cloud WAN dramatically reduces manual overhead through automation (e.g., automatic VPC attachment, network tagging, and consistent policy enforcement), enabling organizations to scale quickly and securely

Programmatic Networking – NaaS Model: The service’s programmable, on-demand model, inspired by Network as a Service (NaaS), reduces the need for complex physical provisioning. This aligns network agility with cloud compute agility, allowing networks to evolve as fast as applications are deployed

Why AWS Cloud WAN Is Better for Managing Network Connectivity

AWS Cloud WAN simplifies and centralizes the way organizations manage connectivity across their global network infrastructure. Here are the key reasons why Cloud WAN is a better solution compared to traditional approaches:

1. Centralized Route Management
   With Cloud WAN, you can manage your network routes centrally using a global network policy. This eliminates the need to configure and maintain individual route tables in Transit Gateways or within VPCs, reducing operational complexity.

2. No Need for Complex Transit Gateway Route Tables
   Traditionally, to connect on-premises networks to multiple AWS Regions, you needed to set up Transit Gateways and manually manage their route tables. Cloud WAN removes this requirement by abstracting and automating routing through its core network policy, making inter-region and hybrid connectivity easier to scale.

3. No More VPC Peering Across Accounts and Regions
   Establishing VPC peering connections across AWS accounts and regions can quickly become unmanageable as the number of VPCs grows. Cloud WAN replaces the need for VPC peering by allowing seamless communication between VPCs—regardless of account or region—through its core network, reducing overhead and increasing scalability.

4. Simplified Network Traffic Inspection Using NFG VPC
   Security inspection becomes streamlined with Cloud WAN. You can designate a centralized Network Firewall Gateway (NFG) VPC for inspection. To inspect traffic between two VPCs (e.g., Spoke 1 and Spoke 2), you just need to:

Attach the NFG VPC to the Cloud WAN core network.

Define routing in the core network policy to send traffic from Spoke 1 to Spoke 2 via the NFG VPC.

This allows all inter-VPC traffic to be inspected centrally without requiring individual appliances or duplicated configurations in each VPC.

🌐 AWS Cloud WAN Deployment – Real Implementation Overview
🧠 Multi-Account Setup with Core Network Sharing
A Core Network is created in one central AWS account and shared to other accounts using Resource Access Manager (RAM).

Each AWS account has:

One or more Cloud WAN attachments for their VPCs.

A /28 subnet specifically created and attached to the Cloud WAN (as per AWS best practices).

A workload subnet (e.g., /16) that handles application traffic.

🗺️ Routing Table Configuration
In each VPC:

The workload subnet routing table includes:

10.3.0.0/16 → local

0.0.0.0/0 → Core Network attachment

This ensures internal traffic stays local, and all external or cross-account/region traffic goes via Cloud WAN.

🌐 Hybrid Connectivity to On-Premises
Direct Connect (DX) and Site-to-Site VPN (S2S) connections are established to integrate the on-premises network.

Using policy-based routing in Cloud WAN's core network policy, traffic is routed:

From S2S VPN to Prod or UAT workloads.

Based on destination prefix or segment.

🔥 Traffic Inspection via Firewall in 2 AZs
A centralized Inspection VPC is deployed.

AWS Network Firewall (NFW) or third-party firewall is hosted behind Gateway Load Balancer (GWLB) across two AZs.

Segment sharing is used to steer traffic through this VPC.

🔁 Traffic Flow
Example: From a workload EC2 instance to another VPC (or internet), the flow is:

EC2 → Subnet → Route Table

Route Table sends 0.0.0.0/0 traffic to Cloud WAN

Cloud WAN core network checks:

If direct segment sharing exists → route directly.

If inspection is required → send traffic to the Inspection VPC

In the Inspection VPC:

Route 0.0.0.0/0 to the GWLB endpoint.

Firewall inspects the traffic.

Traffic returns via GWLB to Cloud WAN.

Cloud WAN forwards to the destination segment or internet gateway (if public access is needed).