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.
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 VPC 1, VPC 2, and virtual gateway 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 VPC 1, virtual gateway 1, 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 3 and VPC 4 attachments.