Propagation Overview

You can create a propagation for each attachment to propagate routes to one or more route tables on an enterprise router.

If you do not want to create a propagation, you can manually add static routes for attachments to the route tables.

Figure 1 Propagated routes and static routes

**Table 1** Propagation description
Attachment Type	Propagated Info	Way to Create Propagation	Description
VPC	VPC CIDR blocks	Auto creation: If Default Route Table Propagation is enabled and the default propagation route table is specified, attachments automatically propagate routes to the default propagation route table. If you want to enable this function when you create an enterprise router, refer to Creating an Enterprise Router. If you want to enable this function after an enterprise router is created, refer to Modifying an Enterprise Router. Manual creation: You can select a route table and create a propagation for an attachment in the route table. For details, see Creating a Propagation for an Attachment in the Route Table.	An attachment can be propagated to different route tables. You can create propagations for attachments in Figure 1 as follows: Auto creation: Propagations are automatically created for the attachments, such as virtual gateway 1, VPN gateway 1, and VPC 1 attachments, in the default propagation route table of the enterprise router. Manual creation: You need to manually create propagations in the custom route table of the enterprise router for attachments, such as virtual gateway 1, VPC 1, VPN gateway 2, and virtual gateway 2 attachments. No propagation: If you do not want to use propagated routes, you need to manually add static routes to the custom route table of the enterprise router for attachments, such as VPC 2 attachment.
Virtual gateway	All routes
VPN gateway	All routes