| name | enabling-lambda-vpc-internet-access |
| description | Enables internet access for AWS Lambda functions deployed in VPC subnets by creating NAT Gateway infrastructure, configuring public/private subnet routing, and updating security groups. Use when a VPC-attached Lambda function cannot reach the internet. |
| version | 1 |
Enabling Lambda VPC Internet Access
Overview
Domain expertise for enabling internet access from AWS Lambda functions running inside VPC private subnets. Lambda functions in a VPC cannot receive public IP addresses, so outbound internet access requires NAT Gateway infrastructure that routes traffic from private subnets through a public subnet to an Internet Gateway.
Enable internet access for a VPC Lambda function
To set up NAT Gateway infrastructure and configure routing for a Lambda function that needs internet access, follow the procedure exactly.
See Lambda VPC internet access setup procedure.
Troubleshooting
NAT Gateway not working
Verify the route table associated with the Lambda subnets has a 0.0.0.0/0 route pointing to the NAT Gateway. See the full procedure for details.
Lambda function timeout
Check that security group outbound rules allow the necessary ports and that both the NAT Gateway and Internet Gateway are properly configured.
Network changes not taking effect
VPC networking changes can take 1–2 minutes to propagate. Wait before testing after creating a NAT Gateway or updating route tables.
Route table association issues
Confirm the Lambda function's subnets are associated with the route table that has the 0.0.0.0/0 route to the NAT Gateway.
