John Ajera

Posted on Jan 26

AWS VPC Endpoints: Secure Private Connectivity

#aws #networking #security #vpc

🔌 AWS VPC Endpoints: Secure Private Connectivity

📌 What is a VPC Endpoint?

VPC Endpoints allow private connectivity between AWS services and your VPC, eliminating the need for internet access.

🎯 Why Use VPC Endpoints?

✅ Enhanced Security – No public IP exposure
✅ Lower Costs – Avoid NAT Gateway charges
✅ Better Performance – Uses AWS backbone network

📜 Requirements

VPC with private subnets
Security Groups allowing internal traffic
IAM Policies for access control
Private DNS enabled (for Interface Endpoints)

🔀 Types of VPC Endpoints

🟢 Interface Endpoints (AWS PrivateLink)

Uses Elastic Network Interfaces (ENI)
Supports most AWS services (e.g., SSM, CloudWatch, EC2 Messages)
Requires security group rules

🔵 Gateway Endpoints

Available only for S3 & DynamoDB
Uses route table entries instead of ENIs
No additional cost

🔧 Setting Up a VPC Endpoint

resource "aws_vpc_endpoint" "ssm" {
  vpc_id              = aws_vpc.example.id
  service_name        = "com.amazonaws.${data.aws_region.current.name}.ssm"
  vpc_endpoint_type   = "Interface"
  subnet_ids          = aws_subnet.private[*].id
  security_group_ids  = [aws_security_group.vpc_endpoints.id]
  private_dns_enabled = true
}

For a complete working example, check out this Terraform demo:
🔗 tf-aws-vpc-endpoint-demo

⚠️ Gotchas & Considerations

Security Group Rules – Must allow inbound traffic
Private DNS – Enable for easier access
Costs – Interface Endpoints have hourly & data charges
Service Limits – Only S3 & DynamoDB support Gateway Endpoints

✅ Pros & Cons

Feature	✅ Pros	❌ Cons
Security	Private AWS traffic	Needs SG fine-tuning
Cost	Avoids NAT fees	Interface costs apply
Performance	Faster, AWS backbone	Region availability varies

🔍 Troubleshooting

🔗 Check Endpoint Status

aws ec2 describe-vpc-endpoints --region <region>

🌐 Verify Connectivity

nc -zv logs.<region>.amazonaws.com 443

🔄 Test IAM Permissions

aws ssm describe-instance-information

🚀 Summary

VPC Endpoints enhance security, reduce costs, and improve performance by keeping AWS service traffic inside the VPC. Plan your security groups and IAM policies carefully to maximize benefits!

🔗 AWS VPC Endpoints Docs

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