# Transit gateway route table attachments in AWS Cloud WAN
Transit gateway route table attachments

Transit gateway route tables contain the rules that determine how your network traffic is routed between your VPCs and VPNs. A transit gateway route table can be added as an attachment type in your AWS Cloud WAN core network. You can create a transit gateway route table attachment through either the console or by using the command line or API. 

Before creating the attachment you must first have created your transit gateway route table. 
+  For more information about transit gateway route tables, see [Routing](https://docs.aws.amazon.com/vpc/latest/tgw/how-transit-gateways-work.html#tgw-routing-overview) in the *AWS Transit Gateway User Guide*.
+ For the steps to create a transit gateway route table, see [Transit gateway route tables](https://docs.aws.amazon.com/vpc/latest/tgw/tgw-route-tables.html) in the *AWS Transit Gateway User Guide*.

**Topics**
+ [Create a transit gateway route table attachment](cloudwan-tgw-attachment-add.md)
+ [View or edit a transit gateway route table attachment](cloudwan-attachments-viewing-editing-rtb.md)

# Create a transit gateway route table attachment for an AWS Cloud WAN core network
Create a transit gateway route table attachment

Add a transit gateway route table attachment to your AWS Cloud WAN core network. 

## Create a transit gateway route table attachment using the console


The following steps create a transit gateway route table attachment for a core network using the console.

**To create a transit gateway route table attachment using the console**

1. Access the Network Manager console at [https://console.aws.amazon.com/networkmanager/home/](https://console.aws.amazon.com/networkmanager/home).

1. Under **Connectivity**, choose **Global networks**.

1. On the **Global networks** page, choose the global network link for the core network you want to add an attachment to.

1. In the navigation pane under the name of the global network, choose **Attachments**.

1. Choose **Create attachment**.

1. Enter a **name** identifying the attachment.

1. From the **Edge location** dropdown list, choose the location where the attachment is located.

1. From the **Attachment type** dropdown list, choose **Transit gateway route table**.

1. In the **Transit gateway route table attachment** section, choose the **Transit gateway peering** that will be used for the route table attachment. For information on creating a peering, see [Create a peering in an AWS Cloud WAN core network](cloudwan-peerings-create.md).

1. From the **Transit gateway route table** list, choose the route table to be used for the peering. For information about creating a transit gateway route table, see [Transit gateway route tables](https://docs.aws.amazon.com/vpc/latest/tgw/tgw-route-tables.html) in the *AWS Transit Gateway Guide*.

1. (Optional) For **Routing policy label**, provide a label that will be used to map this policy to attachments. The policy will automatically be applied to any attachment tagged with the same label.

1. (Optional) In the **Tags** section, add **Key** and **Value** tags to help identify this resource. You can add multiple tags by choosing **Add tag**, or remove any tag by choosing **Remove tag**.

1. Choose **Create attachment**.

## Create a transit gateway route table attachment using the command line or API


Use the command line or API to create an AWS Cloud WAN transit gateway route table attachment.

**To create a transit gateway route table attachment using the command line or API**
+ Use `create-transit-gateway-route-table-attachment`. See [create-transit-gateway-route-table-attachment](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/networkmanager/create-transit-gateway-route-table-attachment.html).

# View or edit an AWS Cloud WAN transit gateway route table attachment
View or edit a transit gateway route table attachment

You can view and edit the key-value tags associated with a transit gateway route table attachment, as well as adding a new attachment or for managing route labels For the steps to add a new transit gateway route table attachment, see[Transit gateway route table attachments in AWS Cloud WAN](cloudwan-tgw-attachment.md).

## View and edit a route table attachment


**To view and edit a route table attachment**

1. Access the Network Manager console at [https://console.aws.amazon.com/networkmanager/home/](https://console.aws.amazon.com/networkmanager/home).

1. Under **Connectivity**, choose **Global networks**.

1. On the **Global networks** page, choose the global network ID.

1. Under **Core network** in the navigation pane, choose **Attachments**.

1. Select the check box for an attachment where the **Resource Type** is **Transit gateway route table**. 

1. To add, edit, or remove tags, choose the **Tags** tab. The current list of tags associated with this attachment are displayed. Choose **Edit tags** to modify or delete current tags, and to add new tags.

## Manage a route table attachment routing policy label


You can create, modify, or delete routing policy labels for an attachment. Once you add or modify a routing policy label, you'll need to map or remap it to an attachment routing policy. Deleting a routing policy label removes any association with an attachment routing policy.

**To manage attachment routing policy labels**

1. Access the Network Manager console at [https://console.aws.amazon.com/networkmanager/home/](https://console.aws.amazon.com/networkmanager/home).

1. Under **Connectivity**, choose **Global networks**.

1. On the **Global networks** page, choose the global network link for the core network with the attachment.

1. In the navigation pane under the name of the global network, choose **Attachments**.

1. Choose the attachment.

1. In the section showing details about the attachment, choose the **Routing policy** tab, choose **Edit**.

1. Choose **Create** to create a new routing policy label, or choose **Edit** modify the **Routing policy label** as needed.

1. After creating or modifying a routing policy label, you can then associate that label with an attachment routing policy.

1. In the **Attachment routing policy association** section choose the attachment routing policy association you want to map to the routing policy label.

You can delete a routing policy labels for an attachment. Once you delete an attachment, the association from an attachment routing policy is removed permanently.

**To delete an attachment routing policy label**

1. Access the Network Manager console at [https://console.aws.amazon.com/networkmanager/home/](https://console.aws.amazon.com/networkmanager/home).

1. Under **Connectivity**, choose **Global networks**.

1. On the **Global networks** page, choose the global network link for the core network with the attachment.

1. In the navigation pane under the name of the global network, choose **Attachments**.

1. Choose the attachment.

1. In the section showing details about the attachment, choose the **Routing policy** tab, choose **Delete**.

1. Choose **Delete** again to confirm the removal. If the routing policy label was mapped to an attachment routing policy, the **Attachment routing policy association** section updates and removes the policy from the list. 

## View a transit gateway route table attachment using the command line or API


Use the command line or API to view a transit gateway route table attachment.

**To view a transit gateway route table attachment using the command line or API**
+ See [get-transit-gateway-route-table-attachment](https://docs.aws.amazon.com/cli/latest/reference/networkmanager/get-transit-gateway-route-table-attachment.html).