AWS Site-to-Site VPN is a fully managed service that creates secure, encrypted connections between your on-premises network or branch office and your Amazon Virtual Private Cloud (VPC). This solution is essential for organizations dealing with hybrid cloud architectures and complex networking requi…AWS Site-to-Site VPN is a fully managed service that creates secure, encrypted connections between your on-premises network or branch office and your Amazon Virtual Private Cloud (VPC). This solution is essential for organizations dealing with hybrid cloud architectures and complex networking requirements.
The service establishes IPsec VPN tunnels between your network and AWS, providing two tunnels per VPN connection for high availability. Each tunnel terminates at a different Availability Zone, ensuring redundancy if one tunnel becomes unavailable.
Key components include:
1. Virtual Private Gateway (VGW): An AWS-managed gateway attached to your VPC that serves as the VPN concentrator on the AWS side.
2. Customer Gateway: A resource representing your physical device or software application on your premises.
3. Transit Gateway: For complex multi-VPC architectures, you can terminate VPN connections on a Transit Gateway instead of individual VGWs, simplifying network management across multiple VPCs and accounts.
Site-to-Site VPN supports both static and dynamic routing using BGP (Border Gateway Protocol). BGP is recommended for production environments as it enables automatic failover and route propagation.
For organizational complexity scenarios, consider:
- Accelerated Site-to-Site VPN: Leverages AWS Global Accelerator to route traffic through the AWS global network, improving performance for geographically distributed offices.
- VPN CloudHub: Enables multiple branch offices to communicate with each other through the AWS VPN infrastructure.
- Combining with AWS Direct Connect: Creates a backup connection strategy where VPN serves as a failover path when Direct Connect experiences issues.
Bandwidth considerations are important as each VPN tunnel supports up to 1.25 Gbps throughput. For higher bandwidth requirements, you can use multiple VPN connections with ECMP (Equal Cost Multi-Path) routing when connecting through Transit Gateway, allowing aggregated throughput across tunnels.
AWS Site-to-Site VPN: Complete Guide for Solutions Architect Professional Exam
Why AWS Site-to-Site VPN is Important
AWS Site-to-Site VPN is a critical component for hybrid cloud architectures, enabling secure connectivity between on-premises data centers and AWS VPCs. Understanding this service is essential for the Solutions Architect Professional exam as it frequently appears in scenarios involving network design, security, and organizational complexity.
What is AWS Site-to-Site VPN?
AWS Site-to-Site VPN creates encrypted IPsec connections between your on-premises network and your Amazon VPCs. It consists of two main components:
• Virtual Private Gateway (VGW): The AWS-side endpoint attached to your VPC • Customer Gateway (CGW): Represents your on-premises VPN device configuration in AWS
Each Site-to-Site VPN connection provides two tunnels for high availability, with each tunnel terminating in a different Availability Zone.
How AWS Site-to-Site VPN Works
1. Setup Process: - Create a Virtual Private Gateway and attach it to your VPC - Create a Customer Gateway representing your on-premises device - Create a Site-to-Site VPN connection linking the VGW and CGW - Configure your on-premises router using the downloaded configuration
2. Tunnel Options: - IKEv1 or IKEv2 protocol support - Pre-shared keys or certificates for authentication - Custom encryption algorithms (AES-128, AES-256) - Dead Peer Detection (DPD) timeout configuration
3. Routing Options: - Static Routing: Manually define which CIDR blocks are accessible - Dynamic Routing (BGP): Automatically exchange routes using Border Gateway Protocol
Key Features and Considerations
• Bandwidth: Each tunnel supports up to 1.25 Gbps throughput • Accelerated VPN: Uses AWS Global Accelerator for improved performance over long distances • Transit Gateway Integration: Attach VPN connections to Transit Gateway for scalable multi-VPC architectures • CloudWatch Monitoring: Monitor tunnel status, bytes in/out, and tunnel state changes
AWS Transit Gateway with VPN
For organizational complexity scenarios, Transit Gateway provides centralized VPN management: - Single VPN connection can provide access to multiple VPCs - Equal Cost Multi-Path (ECMP) routing enables aggregated bandwidth - Supports up to 50 Gbps with multiple VPN connections using ECMP
Exam Tips: Answering Questions on AWS Site-to-Site VPN
Scenario Recognition: • When questions mention connecting on-premises to AWS securely over the internet, think Site-to-Site VPN • For requirements involving quick setup times, VPN is preferred over Direct Connect • When cost optimization is mentioned alongside hybrid connectivity, VPN is typically more economical
Key Decision Points: • VPN vs Direct Connect: VPN for internet-based encryption, faster setup; Direct Connect for dedicated, consistent performance • VPN + Direct Connect: Use VPN as backup for Direct Connect or for encrypted traffic over Direct Connect public VIF • Single VPC vs Multiple VPCs: Use Transit Gateway when connecting VPN to multiple VPCs
Common Exam Scenarios: • Hybrid architectures requiring encrypted connectivity • Failover solutions combining Direct Connect with VPN backup • Multi-account, multi-VPC connectivity through Transit Gateway • Performance optimization using Accelerated Site-to-Site VPN
Watch for These Keywords: • "Encrypted connection over internet" → Site-to-Site VPN • "Redundant hybrid connectivity" → VPN with two tunnels or VPN + Direct Connect • "Aggregate bandwidth for VPN" → Transit Gateway with ECMP • "Quick deployment for hybrid" → VPN (not Direct Connect which takes weeks/months)
Remember: Always consider high availability requirements. A single Site-to-Site VPN provides two tunnels, but for maximum resilience, implement multiple VPN connections with different Customer Gateways or combine with Direct Connect.