📖 What is AWS PrivateLink?
AWS PrivateLink provides private connectivity between VPCs, AWS services, and third-party services without exposing traffic to the public internet. It uses VPC Endpoints to route traffic over the AWS internal network, significantly reducing attack surfaces and improving security for sensitive data.
"When you see "avoiding the public internet" or "private access to a service," think PrivateLink (Interface Endpoints)."
📚 Certification: AWS Certified Solutions Architect - Associate (SAA-C03)
🔑 What are the Key Concepts of AWS PrivateLink?
- ▸ Interface VPC Endpoints utilize Elastic Network Interfaces (ENIs) with private IP addresses to enable communication between your VPC and supported services.
- ▸ The Service Provider model allows a company to expose a specific service to other AWS accounts using a Network Load Balancer.
- ▸ PrivateLink eliminates the need for Internet Gateways, NAT Gateways, or public IP addresses, significantly reducing the network attack surface.
- ▸ Unlike VPC Peering, PrivateLink allows connectivity between VPCs even if they have overlapping CIDR blocks, as it operates at the service level.
- ▸ Private DNS names can be enabled for endpoints, allowing applications to use standard service URLs while routing traffic privately.
🎯 How does AWS PrivateLink appear on the SAA-C03 Exam?
You may be asked to design a secure connection to a third-party SaaS application hosted on AWS while ensuring traffic never traverses the public internet.
A scenario might describe a requirement to provide a shared internal service to hundreds of different consumer VPCs without managing complex VPC peering meshes.
Expect questions where you must choose between a NAT Gateway and an Interface Endpoint to allow private EC2 instances to access AWS APIs.
❓ Frequently Asked Questions
How does PrivateLink differ from VPC Peering?
VPC Peering connects two entire networks, allowing all allowed traffic between them. PrivateLink only exposes a specific service, providing a more secure, granular connection that avoids routing conflicts.
Can I use PrivateLink to solve overlapping IP address ranges?
Yes. Because PrivateLink uses an ENI in the consumer VPC, it doesn't require the two VPCs to have unique CIDR blocks, unlike VPC Peering or Transit Gateway.
When should I use a Gateway Endpoint instead of an Interface Endpoint?
Use Gateway Endpoints for S3 and DynamoDB for cost-efficiency and simplicity. Use Interface Endpoints (PrivateLink) for almost all other AWS services and third-party provider services.