# AWS Transit Gateway Terraform module Terraform module which creates Transit Gateway resources on AWS. ## Usage with VPC module ```hcl module "tgw" { source = "terraform-aws-modules/transit-gateway/aws" name = "my-tgw" description = "My TGW shared with several other AWS accounts" enable_auto_accept_shared_attachments = true vpc_attachments = { vpc = { vpc_id = "vpc-1234556abcdef" subnet_ids = ["subnet-abcde012", "subnet-bcde012a", "subnet-fghi345a"] dns_support = true ipv6_support = true tgw_routes = [ { destination_cidr_block = "30.0.0.0/16" }, { blackhole = true destination_cidr_block = "40.0.0.0/20" } ] } } ram_allow_external_principals = true ram_principals = [307990089504] tags = { Terraform = "true" Environment = "dev" } } ``` ## Examples - [Complete example](https://github.com/terraform-aws-modules/terraform-aws-transit-gateway/tree/master/examples/complete) shows TGW in combination with the [VPC module](https://github.com/terraform-aws-modules/terraform-aws-vpc) and [Resource Access Manager (RAM)](https://aws.amazon.com/ram/). - [Multi-account example](https://github.com/terraform-aws-modules/terraform-aws-transit-gateway/tree/master/examples/multi-account) shows TGW resources shared with different AWS accounts (via [Resource Access Manager (RAM)](https://aws.amazon.com/ram/)). ## Requirements | Name | Version | | ---- | ------- | | [terraform](#requirement\_terraform) | >= 1.5.7 | | [aws](#requirement\_aws) | >= 6.28 | ## Providers | Name | Version | | ---- | ------- | | [aws](#provider\_aws) | >= 6.28 | ## Modules No modules. ## Resources | Name | Type | | ---- | ---- | | [aws_ec2_tag.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/ec2_tag) | resource | | [aws_ec2_transit_gateway.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/ec2_transit_gateway) | resource | | [aws_ec2_transit_gateway_route.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/ec2_transit_gateway_route) | resource | | [aws_ec2_transit_gateway_route_table.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/ec2_transit_gateway_route_table) | resource | | [aws_ec2_transit_gateway_route_table_association.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/ec2_transit_gateway_route_table_association) | resource | | [aws_ec2_transit_gateway_route_table_propagation.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/ec2_transit_gateway_route_table_propagation) | resource | | [aws_ec2_transit_gateway_vpc_attachment.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/ec2_transit_gateway_vpc_attachment) | resource | | [aws_ram_principal_association.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/ram_principal_association) | resource | | [aws_ram_resource_association.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/ram_resource_association) | resource | | [aws_ram_resource_share.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/ram_resource_share) | resource | | [aws_ram_resource_share_accepter.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/ram_resource_share_accepter) | resource | | [aws_route.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/route) | resource | ## Inputs | Name | Description | Type | Default | Required | | ---- | ----------- | ---- | ------- | :------: | | [amazon\_side\_asn](#input\_amazon\_side\_asn) | The Autonomous System Number (ASN) for the Amazon side of the gateway. By default the TGW is created with the current default Amazon ASN. | `string` | `null` | no | | [create\_tgw](#input\_create\_tgw) | Controls if TGW should be created (it affects almost all resources) | `bool` | `true` | no | | [create\_tgw\_routes](#input\_create\_tgw\_routes) | Controls if TGW Route Table / Routes should be created | `bool` | `true` | no | | [description](#input\_description) | Description of the EC2 Transit Gateway | `string` | `null` | no | | [enable\_auto\_accept\_shared\_attachments](#input\_enable\_auto\_accept\_shared\_attachments) | Whether resource attachment requests are automatically accepted | `bool` | `false` | no | | [enable\_default\_route\_table\_association](#input\_enable\_default\_route\_table\_association) | Whether resource attachments are automatically associated with the default association route table | `bool` | `true` | no | | [enable\_default\_route\_table\_propagation](#input\_enable\_default\_route\_table\_propagation) | Whether resource attachments automatically propagate routes to the default propagation route table | `bool` | `true` | no | | [enable\_dns\_support](#input\_enable\_dns\_support) | Should be true to enable DNS support in the TGW | `bool` | `true` | no | | [enable\_encryption\_support](#input\_enable\_encryption\_support) | Should be true to enable encryption support in the TGW | `bool` | `false` | no | | [enable\_multicast\_support](#input\_enable\_multicast\_support) | Whether multicast support is enabled | `bool` | `false` | no | | [enable\_sg\_referencing\_support](#input\_enable\_sg\_referencing\_support) | Indicates whether to enable security group referencing support | `bool` | `true` | no | | [enable\_vpn\_ecmp\_support](#input\_enable\_vpn\_ecmp\_support) | Whether VPN Equal Cost Multipath Protocol support is enabled | `bool` | `true` | no | | [name](#input\_name) | Name to be used on all the resources as identifier | `string` | `""` | no | | [ram\_allow\_external\_principals](#input\_ram\_allow\_external\_principals) | Indicates whether principals outside your organization can be associated with a resource share. | `bool` | `false` | no | | [ram\_name](#input\_ram\_name) | The name of the resource share of TGW | `string` | `""` | no | | [ram\_principals](#input\_ram\_principals) | A list of principals to share TGW with. Possible values are an AWS account ID, an AWS Organizations Organization ARN, or an AWS Organizations Organization Unit ARN | `list(string)` | `[]` | no | | [ram\_resource\_share\_arn](#input\_ram\_resource\_share\_arn) | ARN of RAM resource share | `string` | `""` | no | | [ram\_tags](#input\_ram\_tags) | Additional tags for the RAM | `map(string)` | `{}` | no | | [region](#input\_region) | Region where the resource(s) will be managed. Defaults to the region set in the provider configuration | `string` | `null` | no | | [share\_tgw](#input\_share\_tgw) | Whether to share your transit gateway with other accounts | `bool` | `true` | no | | [tags](#input\_tags) | A map of tags to add to all resources | `map(string)` | `{}` | no | | [tgw\_default\_route\_table\_tags](#input\_tgw\_default\_route\_table\_tags) | Additional tags for the Default TGW route table | `map(string)` | `{}` | no | | [tgw\_route\_table\_tags](#input\_tgw\_route\_table\_tags) | Additional tags for the TGW route table | `map(string)` | `{}` | no | | [tgw\_tags](#input\_tgw\_tags) | Additional tags for the TGW | `map(string)` | `{}` | no | | [tgw\_vpc\_attachment\_tags](#input\_tgw\_vpc\_attachment\_tags) | Additional tags for VPC attachments | `map(string)` | `{}` | no | | [timeouts](#input\_timeouts) | Create, update, and delete timeout configurations for the transit gateway |

object({
    create = optional(string)
    update = optional(string)
    delete = optional(string)
  })

| `null` | no | | [transit\_gateway\_cidr\_blocks](#input\_transit\_gateway\_cidr\_blocks) | One or more IPv4 or IPv6 CIDR blocks for the transit gateway. Must be a size /24 CIDR block or larger for IPv4, or a size /64 CIDR block or larger for IPv6 | `list(string)` | `[]` | no | | [transit\_gateway\_route\_table\_id](#input\_transit\_gateway\_route\_table\_id) | Identifier of EC2 Transit Gateway Route Table to use with the Target Gateway when reusing it between multiple TGWs | `string` | `null` | no | | [vpc\_attachments](#input\_vpc\_attachments) | Maps of maps of VPC details to attach to TGW. Type 'any' to disable type validation by Terraform. | `any` | `{}` | no | ## Outputs | Name | Description | | ---- | ----------- | | [ec2\_transit\_gateway\_arn](#output\_ec2\_transit\_gateway\_arn) | EC2 Transit Gateway Amazon Resource Name (ARN) | | [ec2\_transit\_gateway\_association\_default\_route\_table\_id](#output\_ec2\_transit\_gateway\_association\_default\_route\_table\_id) | Identifier of the default association route table | | [ec2\_transit\_gateway\_id](#output\_ec2\_transit\_gateway\_id) | EC2 Transit Gateway identifier | | [ec2\_transit\_gateway\_owner\_id](#output\_ec2\_transit\_gateway\_owner\_id) | Identifier of the AWS account that owns the EC2 Transit Gateway | | [ec2\_transit\_gateway\_propagation\_default\_route\_table\_id](#output\_ec2\_transit\_gateway\_propagation\_default\_route\_table\_id) | Identifier of the default propagation route table | | [ec2\_transit\_gateway\_route\_ids](#output\_ec2\_transit\_gateway\_route\_ids) | List of EC2 Transit Gateway Route Table identifier combined with destination | | [ec2\_transit\_gateway\_route\_table\_association](#output\_ec2\_transit\_gateway\_route\_table\_association) | Map of EC2 Transit Gateway Route Table Association attributes | | [ec2\_transit\_gateway\_route\_table\_association\_ids](#output\_ec2\_transit\_gateway\_route\_table\_association\_ids) | List of EC2 Transit Gateway Route Table Association identifiers | | [ec2\_transit\_gateway\_route\_table\_default\_association\_route\_table](#output\_ec2\_transit\_gateway\_route\_table\_default\_association\_route\_table) | Boolean whether this is the default association route table for the EC2 Transit Gateway | | [ec2\_transit\_gateway\_route\_table\_default\_propagation\_route\_table](#output\_ec2\_transit\_gateway\_route\_table\_default\_propagation\_route\_table) | Boolean whether this is the default propagation route table for the EC2 Transit Gateway | | [ec2\_transit\_gateway\_route\_table\_id](#output\_ec2\_transit\_gateway\_route\_table\_id) | EC2 Transit Gateway Route Table identifier | | [ec2\_transit\_gateway\_route\_table\_propagation](#output\_ec2\_transit\_gateway\_route\_table\_propagation) | Map of EC2 Transit Gateway Route Table Propagation attributes | | [ec2\_transit\_gateway\_route\_table\_propagation\_ids](#output\_ec2\_transit\_gateway\_route\_table\_propagation\_ids) | List of EC2 Transit Gateway Route Table Propagation identifiers | | [ec2\_transit\_gateway\_vpc\_attachment](#output\_ec2\_transit\_gateway\_vpc\_attachment) | Map of EC2 Transit Gateway VPC Attachment attributes | | [ec2\_transit\_gateway\_vpc\_attachment\_ids](#output\_ec2\_transit\_gateway\_vpc\_attachment\_ids) | List of EC2 Transit Gateway VPC Attachment identifiers | | [ram\_principal\_association\_id](#output\_ram\_principal\_association\_id) | The Amazon Resource Name (ARN) of the Resource Share and the principal, separated by a comma | | [ram\_resource\_share\_id](#output\_ram\_resource\_share\_id) | The Amazon Resource Name (ARN) of the resource share | ## Authors Module is maintained by [Anton Babenko](https://github.com/antonbabenko) with help from [these awesome contributors](https://github.com/terraform-aws-modules/terraform-aws-transit-gateway/graphs/contributors). ## License Apache 2 Licensed. See [LICENSE](https://github.com/terraform-aws-modules/terraform-aws-transit-gateway/tree/master/LICENSE) for full details.

AWS Transit Gateway Terraform module

Terraform Module Source