VPC endpoints for private access in DynamoDB

Introduction

VPC endpoints let you connect to DynamoDB securely without using the internet. This keeps your data safe and private.

When you want to access DynamoDB from your private cloud network without exposing traffic to the internet.

When you need to improve security by keeping data transfer inside your cloud environment.

When your applications run in a private subnet and cannot access the internet.

When you want to reduce data transfer costs by avoiding internet gateways.

When you want to control access to DynamoDB using your network policies.

Syntax

DynamoDB

aws ec2 create-vpc-endpoint \
  --vpc-id vpc-123abc \
  --service-name com.amazonaws.<region>.dynamodb \
  --route-table-ids rtb-123abc rtb-456def

Replace vpc-123abc with your VPC ID.

Use the correct region for your AWS region, like us-east-1.

Examples

This command creates a VPC endpoint for DynamoDB in the us-east-1 region using two route tables.

DynamoDB

aws ec2 create-vpc-endpoint \
  --vpc-id vpc-0a1b2c3d4e5f6g7h8 \
  --service-name com.amazonaws.us-east-1.dynamodb \
  --route-table-ids rtb-0a1b2c3d rtb-1a2b3c4d

This command shows details about a specific VPC endpoint by its ID.

DynamoDB

aws ec2 describe-vpc-endpoints --vpc-endpoint-ids vpce-1234567890abcdef0

Sample Program

This example creates a VPC endpoint for DynamoDB in the us-west-2 region. It uses two route tables to allow private access.

DynamoDB

aws ec2 create-vpc-endpoint \
  --vpc-id vpc-0abc123def456ghi7 \
  --service-name com.amazonaws.us-west-2.dynamodb \
  --route-table-ids rtb-0abc1234 rtb-0def5678

Important Notes

VPC endpoints for DynamoDB use the Gateway type, which adds route entries to your route tables.

Make sure your route tables are associated with the subnets where your resources reside.

After creating the endpoint, traffic to DynamoDB is automatically routed privately. No application changes are required.

Summary

VPC endpoints let you connect to DynamoDB privately without internet access.

Use the AWS CLI to create and manage VPC endpoints with your VPC and route tables.

This improves security and can reduce costs by keeping traffic inside your cloud network.

Practice

1. What is the main benefit of using a VPC endpoint for DynamoDB access?

easy

A. It allows private access to DynamoDB without using the internet.

B. It increases the internet bandwidth for DynamoDB queries.

C. It automatically backs up DynamoDB tables.

D. It enables cross-region replication of DynamoDB data.

Solution

1. Step 1: Understand VPC endpoint purpose

   A VPC endpoint lets you connect to AWS services privately inside your cloud network without internet traffic.

2. Step 2: Identify benefit for DynamoDB

   Using a VPC endpoint for DynamoDB means your data traffic stays inside AWS, improving security and privacy.

3. Final Answer:

   It allows private access to DynamoDB without using the internet. -> Option A

4. Quick Check:

   Private access = VPC endpoint benefit [OK]

Hint: VPC endpoints keep traffic inside AWS, no internet needed [OK]

Common Mistakes:

• Confusing VPC endpoints with internet bandwidth
• Thinking VPC endpoints backup data
• Assuming VPC endpoints replicate data across regions

2. Which AWS CLI command is used to create a VPC endpoint for DynamoDB?

easy

A. aws s3 create-vpc-endpoint --service-name com.amazonaws.region.s3

B. aws dynamodb create-endpoint --vpc-id vpc-123456

C. aws ec2 create-vpc-endpoint --service-name com.amazonaws.region.dynamodb

D. aws ec2 create-vpc --service-name dynamodb

Solution

1. Step 1: Identify correct AWS CLI service for VPC endpoints

   VPC endpoints are managed via the EC2 service commands, not DynamoDB or S3 commands.

2. Step 2: Match correct syntax for DynamoDB endpoint

   The command uses 'aws ec2 create-vpc-endpoint' with the service name for DynamoDB in the region.

3. Final Answer:

   aws ec2 create-vpc-endpoint --service-name com.amazonaws.region.dynamodb -> Option C

4. Quick Check:

   EC2 CLI + DynamoDB service name = create VPC endpoint [OK]

Hint: VPC endpoints use EC2 CLI, not DynamoDB CLI [OK]

Common Mistakes:

• Using dynamodb CLI instead of ec2 CLI
• Confusing S3 service name with DynamoDB
• Trying to create VPC instead of VPC endpoint

3. Given this AWS CLI command, what will it do?

aws ec2 create-vpc-endpoint --vpc-id vpc-abc123 --service-name com.amazonaws.us-east-1.dynamodb --subnet-ids subnet-1a2b3c --security-group-ids sg-123abc

medium

A. Creates a new VPC with DynamoDB access enabled.

B. Creates a VPC endpoint for DynamoDB in the specified VPC with subnet and security group.

C. Deletes the specified subnet and security group.

D. Creates a DynamoDB table in the specified subnet.

Solution

1. Step 1: Analyze the command components

   The command uses 'create-vpc-endpoint' with a VPC ID, service name for DynamoDB, subnet IDs, and security group IDs.

2. Step 2: Understand the effect of the command

   This creates a VPC endpoint inside the given VPC, allowing private DynamoDB access through specified subnets and security groups.

3. Final Answer:

   Creates a VPC endpoint for DynamoDB in the specified VPC with subnet and security group. -> Option B

4. Quick Check:

   Create VPC endpoint + DynamoDB service = private access setup [OK]

Hint: Look for 'create-vpc-endpoint' and DynamoDB service name [OK]

Common Mistakes:

• Thinking it creates a new VPC
• Confusing creation with deletion
• Assuming it creates DynamoDB tables

4. You tried to create a VPC endpoint for DynamoDB but got an error: "InvalidSubnetID.NotFound". What is the most likely cause?

medium

A. The security group ID is missing from the command.

B. The DynamoDB table name is incorrect.

C. Your VPC does not have an internet gateway attached.

D. The subnet ID provided does not exist in your AWS account or region.

Solution

1. Step 1: Understand the error message

   "InvalidSubnetID.NotFound" means the subnet ID given is not found or invalid in your AWS environment.

2. Step 2: Identify cause related to subnet

   This usually happens if the subnet ID is mistyped, deleted, or belongs to a different region/account.

3. Final Answer:

   The subnet ID provided does not exist in your AWS account or region. -> Option D

4. Quick Check:

   InvalidSubnetID error = wrong or missing subnet ID [OK]

Hint: Check subnet ID spelling and region first [OK]

Common Mistakes:

• Blaming DynamoDB table name for subnet errors
• Assuming internet gateway is required for VPC endpoint
• Ignoring subnet ID in error diagnosis

5. You want to ensure all DynamoDB traffic from your private subnet uses a VPC endpoint without going through the internet. Which setup is required?

hard

A. Create a DynamoDB VPC endpoint in your VPC, associate it with your private subnet, and update route tables accordingly.

B. Attach an internet gateway to your VPC and enable public IPs on your instances.

C. Create a NAT gateway and route all DynamoDB traffic through it.

D. Enable DynamoDB global tables for cross-region access.

Solution

1. Step 1: Understand private subnet traffic needs

   Private subnets do not have direct internet access, so to reach DynamoDB privately, a VPC endpoint is needed.

2. Step 2: Configure VPC endpoint and routing

   Create a DynamoDB VPC endpoint, associate it with the private subnet, and update route tables so traffic to DynamoDB uses the endpoint.

3. Step 3: Exclude internet gateway or NAT for this traffic

   Internet gateway or NAT gateway routes send traffic outside AWS, which is not desired for private access.

4. Final Answer:

   Create a DynamoDB VPC endpoint in your VPC, associate it with your private subnet, and update route tables accordingly. -> Option A

5. Quick Check:

   VPC endpoint + private subnet + route update = private DynamoDB access [OK]

Hint: Use VPC endpoint and route tables for private subnet access [OK]

Common Mistakes:

• Using internet gateway for private subnet traffic
• Routing DynamoDB traffic through NAT gateway unnecessarily
• Confusing global tables with network setup