# Creating AWS Transit Gateway VPC attachment
This example shows how you can use this module with `transit_gateway` subnets, and AWS Transit Gateway VPC attachment. This examples creates the following:
* AWS Transit Gateway.
* IPv4 managed prefix list with two entries.
* The VPC module creates the following:
* Four sets of subnets (*public*, *private\_with\_egress*, *private\_dualstack*, and *transit\_gateway*)
* Transit Gateway VPC attachment.
* Routing to Transit Gateway attachment:
* IPv4 routes from *public*, *private\_with\_egress*, and *private\_dualstack*.
* IPv6 routes from *private\_dualstack*.
## Requirements
| Name | Version |
|------|---------|
| [terraform](#requirement\_terraform) | >= 1.3.0 |
| [aws](#requirement\_aws) | >= 3.72.0 |
## Providers
| Name | Version |
|------|---------|
| [aws](#provider\_aws) | >= 3.72.0 |
## Modules
| Name | Source | Version |
|------|--------|---------|
| [vpc](#module\_vpc) | aws-ia/vpc/aws | >= 4.2.0 |
## Resources
| Name | Type |
|------|------|
| [aws_ec2_managed_prefix_list.example](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/ec2_managed_prefix_list) | resource |
| [aws_ec2_transit_gateway.example](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/ec2_transit_gateway) | resource |
| [aws_availability_zones.current](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/availability_zones) | data source |
## Inputs
| Name | Description | Type | Default | Required |
|------|-------------|------|---------|:--------:|
| [aws\_region](#input\_aws\_region) | AWS Regions to create in Cloud WAN's core network. | `string` | `"eu-west-2"` | no |
| [prefixes](#input\_prefixes) | (optional) describe your variable | `map(string)` | {
"internal": "192.168.0.0/16",
"primary": "10.0.0.0/8"
} | no |
## Outputs
| Name | Description |
|------|-------------|
| [private\_subnets\_tags\_length](#output\_private\_subnets\_tags\_length) | Count of private subnet tags for a single az. |
| [tgw\_subnets\_tags\_length](#output\_tgw\_subnets\_tags\_length) | Count of tgw subnet tags for a single az. |