# Configure Lambda functions with external VPCs in Infrastructure Composer
<a name="using-composer-services-vpc-configure"></a>

To start configuring a Lambda function with a VPC that is defined on another template, use the **Lambda Function** enhanced component card. This card represents a Lambda function using the AWS Serverless Application Model (AWS SAM) `AWS::Serverless::Function` resource type.

**To configure a Lambda function with a VPC from an external template**

1. From the **Lambda Function** resource properties panel, expand the **VPC settings (advanced)** dropdown section.

1. Select **Assign to external VPC**.

1. Provide values for the security groups and subnets to configure for the Lambda function. See [Security group and subnet identifiers](using-composer-services-vpc-tag.md#using-composer-services-vpc-configure-ids) for details.

1. **Save** your changes.