AWS Site-to-Site VPN is a critical connectivity solution for migrating workloads from on-premises data centers to AWS cloud infrastructure. It establishes secure, encrypted tunnels between your corporate network and your Amazon Virtual Private Cloud (VPC) using IPsec protocol.
During migration pro…AWS Site-to-Site VPN is a critical connectivity solution for migrating workloads from on-premises data centers to AWS cloud infrastructure. It establishes secure, encrypted tunnels between your corporate network and your Amazon Virtual Private Cloud (VPC) using IPsec protocol.
During migration projects, Site-to-Site VPN serves as a foundational connectivity layer that enables seamless data transfer and application communication between existing on-premises systems and newly deployed AWS resources. This hybrid connectivity approach allows organizations to execute phased migrations rather than requiring complete cutover scenarios.
Key components include the Virtual Private Gateway (VGW) on the AWS side and a Customer Gateway device in your data center. AWS supports both static and dynamic (BGP) routing configurations. For enhanced reliability, AWS provisions two VPN tunnels per connection, each terminating at different availability zones.
From a migration perspective, Site-to-Site VPN offers several advantages. It provides quick deployment timeframes, typically operational within hours rather than weeks. The solution requires minimal upfront investment compared to dedicated connections like AWS Direct Connect. It also serves as an excellent backup path when used alongside Direct Connect for mission-critical workloads.
Performance considerations include bandwidth limitations of approximately 1.25 Gbps per tunnel and latency variations due to internet routing. For large-scale data migrations, organizations often combine VPN with AWS DataSync, AWS Transfer Family, or AWS Snow Family devices.
Best practices for migration scenarios include implementing VPN CloudWatch monitoring, configuring appropriate timeout settings for long-running data transfers, and establishing proper security group rules. Transit Gateway can centralize multiple VPN connections when migrating complex multi-VPC architectures.
Site-to-Site VPN remains essential for maintaining business continuity during migration phases, enabling applications to communicate across environments until complete cloud transition is achieved.
Site-to-Site VPN for Migration - AWS Solutions Architect Professional Guide
Why Site-to-Site VPN Migration is Important
Site-to-Site VPN serves as a foundational connectivity option when migrating workloads from on-premises data centers to AWS. It provides a secure, encrypted tunnel over the public internet, enabling organizations to establish hybrid connectivity quickly and cost-effectively. Understanding this technology is crucial for the AWS Solutions Architect Professional exam because it represents the most common starting point for cloud migration journeys.
What is Site-to-Site VPN?
AWS Site-to-Site VPN creates an IPsec VPN connection between your on-premises network and your Amazon VPC. It consists of two VPN tunnels for redundancy, connecting to a Virtual Private Gateway (VGW) or Transit Gateway on the AWS side and a Customer Gateway on your premises.
Key Components: - Virtual Private Gateway (VGW): The VPN concentrator on the AWS side attached to your VPC - Customer Gateway: Represents your on-premises VPN device in AWS - Transit Gateway: Alternative attachment point for VPN connections, enabling hub-and-spoke architectures - VPN Tunnels: Two encrypted tunnels per connection for high availability
How Site-to-Site VPN Works for Migration
1. Initial Setup: Create a Customer Gateway representing your on-premises device, then create a Virtual Private Gateway attached to your target VPC
2. Connection Establishment: Configure the VPN connection and download the configuration file for your on-premises device
3. Routing Configuration: Enable route propagation in your VPC route tables or configure static routes
4. Data Transfer: Once tunnels are active, migrate data and workloads through the encrypted connection
Migration Strategies Using Site-to-Site VPN
Phased Migration: Use VPN for initial connectivity, allowing gradual workload migration while maintaining hybrid operations
Rehost (Lift and Shift): Replicate servers to AWS while applications communicate back to on-premises systems via VPN
Database Migration: Use AWS DMS over VPN connection to migrate databases with minimal downtime
Transitioning to Direct Connect: Start with VPN for quick setup, then implement AWS Direct Connect for production workloads requiring consistent performance
Performance Considerations
- Maximum throughput: Approximately 1.25 Gbps per VPN tunnel - Latency varies based on internet conditions - Consider AWS Global Accelerator with VPN for improved performance - Use VPN over Direct Connect for encrypted traffic on dedicated connections
High Availability Patterns
- Deploy redundant Customer Gateway devices on-premises - Use both VPN tunnels actively with ECMP (Equal Cost Multi-Path) routing - Consider Transit Gateway for centralized VPN management across multiple VPCs - Implement VPN as backup for Direct Connect connections
Exam Tips: Answering Questions on Site-to-Site VPN for Migration
Scenario Recognition: - When questions mention quick setup or time-sensitive migration, Site-to-Site VPN is often the answer - Look for keywords like encrypted connection over internet or hybrid connectivity - Budget-conscious scenarios favor VPN over Direct Connect initially
Common Question Patterns: - Migration requiring connectivity within hours or days points to VPN - Questions about backup connectivity for Direct Connect often involve VPN - Multi-VPC connectivity scenarios may require Transit Gateway with VPN attachments
Key Differentiators to Remember: - VPN: Quick to establish, variable performance, lower cost - Direct Connect: Takes weeks to provision, consistent performance, higher cost - VPN over Direct Connect: Provides encryption on dedicated connection
Watch for These Traps: - Do not confuse Client VPN with Site-to-Site VPN - Remember VPN has two tunnels by default for redundancy - Transit Gateway supports ECMP across multiple VPN connections for increased bandwidth
Best Practices for Exam Answers: - Choose VPN when the scenario emphasizes speed of deployment - Select Direct Connect when consistent network performance is the priority - Recommend both when high availability and failover are requirements - Consider Transit Gateway when multiple VPCs need on-premises connectivity