How do I migrate my network traffic from a Direct Connect virtual interface associated with a virtual private gateway to a Direct Connect gateway?

Short description

To migrate traffic from a Direct Connect virtual interface that's associated with a virtual private gateway to a new Direct Connect gateway, you must create a new virtual interface. When you create the new virtual interface, be sure to associate it with your new Direct Connect gateway. Then, use Border Gateway Protocol (BGP) attributes on your network device (such as AS path prepending) to migrate traffic to the Direct Connect gateway with minimal downtime.

Resolution

Note: Before proceeding, check your vendor documentation for instructions on how to configure BGP on your specific network device.

Perform the following steps during a scheduled maintenance window to minimize downtime:

1. Create a new Direct Connect gateway.
2. Create a new private virtual interface.
   Important: During creation, be sure to associate the virtual interface with the Direct Connect gateway you created in the previous step.
3. Associate the virtual private gateway that's already attached to your virtual private cloud (VPC) with the Direct Connect gateway that you just created.
4. (Optional)To minimize downtime, pre-stage the configuration on your network device for the new virtual interface associated with the new Direct Connect gateway.
5. Use BGP to configure a longer AS_Path routing policy on the same prefixes that you’re configuring the new virtual interface to advertise. This step configures outbound traffic from AWS to prefer the existing virtual interface route (with a shorter AS_Path).
   Note: To be sure that traffic from your network device still egresses from the existing virtual interface, use the Local Preference BGP attribute on your network device.
6. During your maintenance window, bring down the BGP session for the existing virtual interface on your network device.
7. Wait for the network traffic from AWS to propagate through the new virtual interface associated with the Direct Connect gateway.
8. Check your network device to confirm that it's receiving traffic from the new virtual interface.

Related information

AWS Direct Connect virtual interfaces

Routing policies and BGP communities