AWS Direct Connect
User Guide

Transit Gateway Associations

You can use an AWS Direct Connect gateway to connect your AWS Direct Connect connection over a transit virtual interface to the VPCs or VPNs that are attached to your transit gateway. You associate a Direct Connect gateway with the transit gateway. Then, create a transit virtual interface for your AWS Direct Connect connection to the Direct Connect gateway.

This configuration offers the following benefits. You can:

  • Manage a single connection for multiple VPCs or VPNs that are in the same Region.

  • Advertise prefixes from on-premises to AWS and from AWS to on-premises.

The following diagram illustrates how the Direct Connect gateway enables you to create a single connection to your Direct Connect connection that all of your VPCs can use.

The solution involves the following components:

  • A transit gateway that has VPC attachments.

  • A Direct Connect gateway.

  • An association between the Direct Connect gateway and the transit gateway.

  • A transit virtual interface that is attached to the Direct Connect gateway.

For information about configuring transit gateways, see Working with Transit Gateways in the Amazon VPC Transit Gateways Guide.

The following rules apply:

  • You cannot use a Direct Connect gateway and a transit gateway in the China Regions.

  • You cannot attach a Direct Connect gateway to a transit gateway when the Direct Connect gateway is already associated with a virtual private gateway or is attached to a private virtual interface.

  • There are limits for creating and using Direct Connect gateways. For more information, see AWS Direct Connect Limits.

  • A Direct Connect gateway supports communication between attached transit virtual interfaces and associated transit gateways only.

  • The transit virtual interface can be in any location, but currently the transit gateway must reside in the United States.

The following Regions support transit gateway associations:

  • US East (N. Virginia)

  • US East (Ohio)

  • US West (N. California) - San Francisco

  • US West (Oregon) - Portland

  • AWS GovCloud (US-East)

  • AWS GovCloud (US-West)

  • Canada (Central) Region - Montreal

Associating and Disassociating Transit Gateways

To associate a transit gateway

  1. Open the AWS Direct Connect console at https://console.aws.amazon.com/directconnect/v2/home.

  2. In the navigation pane, choose Direct Connect Gateways and then select the Direct Connect gateway.

  3. Choose View details.

  4. Choose Gateway associations and then choose Associate gateway.

  5. For Gateways, choose the transit gateway to associate, and then choose Associate gateway.

You can view all of the gateways that are associated with the Direct Connect gateway by choosing Gateway associations.

To disassociate a transit gateway

  1. Open the AWS Direct Connect console at https://console.aws.amazon.com/directconnect/v2/home.

  2. In the navigation pane, choose Direct Connect gateways and then select the Direct Connect gateway.

  3. Choose View details.

  4. Choose Gateway associations and then select the transit gateway.

  5. Choose Disassociate.

To associate a transit gateway using the command line or API

To view the transit gateways associated with a Direct Connect gateway using the command line or API

To disassociate a transit gateway using the command line or API

Creating a Transit Virtual Interface to the Direct Connect Gateway

To connect your AWS Direct Connect connection to the transit gateway, you must create a transit interface for your connection. Specify the Direct Connect gateway to which to connect.

Important

If you associate your transit gateway with one or more Direct Connect gateways, the Autonomous System Number (ASN) used by the transit gateway and the Direct Connect gateway must be different. For example, if you use the default ASN 64512 for both the transit gateway and the Direct Connect gateway, the association request fails.

To provision a transit virtual interface to a Direct Connect gateway

  1. Open the AWS Direct Connect console at https://console.aws.amazon.com/directconnect/v2/home.

  2. In the navigation pane, choose Virtual Interfaces.

  3. Choose Create virtual interface.

  4. Under Virtual interface type, for Type, choose Transit.

  5. Under Transit virtual interface settings, do the following:

    1. For Virtual interface name, enter a name for the virtual interface.

    2. For Connection, choose the Direct Connect connection that you want to use for this interface.

    3. For Virtual interface owner, choose My AWS account if the virtual interface is for your AWS account.

    4. For Direct Connect gateway, select the Direct Connect gateway.

    5. For VLAN, enter the ID number for your virtual local area network (VLAN).

    6. For BGP ASN, enter the Border Gateway Protocol (BGP) Autonomous System Number (ASN) of your gateway.

  6. Under Additional Settings, do the following:

    1. To configure an IPv4 BGP or an IPv6 peer, do the following:

      [IPv4] To configure an IPv4 BGP peer, choose IPv4 and do one of the following:

      • To specify these IP addresses yourself, for Your router peer ip, enter the destination IPv4 CIDR address to which Amazon should send traffic.

      • For Amazon router peer ip, enter the IPv4 CIDR address to use to send traffic to AWS.

      [IPv6] To configure an IPv6 BGP peer, choose IPv6. The peer IPv6 addresses are automatically assigned from Amazon's pool of IPv6 addresses. You cannot specify custom IPv6 addresses.

    2. To change the maximum transmission unit (MTU) from 1500 (default) to 8500 (jumbo frames), select Jumbo MTU (MTU size 8500).

    3. (Optional) Add or remove a tag.

      [Add a tag] Choose Add tag and do the following:

      • For Key, enter the key name.

      • For Value, enter the key value.

      [Remove a tag] Next to the tag, choose Remove tag.

  7. Choose Create virtual interface.

After you've created the virtual interface, you can download the router configuration for your device. For more information, see Downloading the Router Configuration File.

To create a transit virtual interface using the command line or API

To view the virtual interfaces that are attached to a Direct Connect gateway using the command line or API