Help Center/ Enterprise Router/ User Guide/ Propagations/ Creating a Propagation for an Attachment in the Route Table
Updated on 2026-07-14 GMT+08:00

Creating a Propagation for an Attachment in the Route Table

Scenarios

You can refer to the following operations to create a propagation for an attachment in the route table of an enterprise router. After a propagation is created, the route information of the attachment can be automatically propagated to the enterprise router route table. This eliminates the need for manual configuration and further improves configuration efficiency.

Constraints

You can create propagations for the same attachment in different route tables.

Automatically Creating a Propagation When Creating an Attachment

If the Default Route Table Propagation function is enabled for an enterprise router, adding an attachment to the enterprise router automatically creates a propagation in the specified propagation route table. The route table will automatically learn the routes of the attachment.

As shown in Figure 1, ER-01 has the Default Route Table Propagation function enabled. Adding an attachment to the enterprise router will automatically create a propagation between the attachment and the propagation route table defaultRouteTable.
Figure 1 Default Route Table Propagation enabled

To enable the Default Route Table Propagation function, refer to the following:

  • When creating an enterprise router, you can enable the Default Route Table Propagation function. The system will automatically create a default route table as the propagation route table. For details, see Creating an Enterprise Router.
  • After an enterprise router is created, you can enable the Default Route Table Propagation function and change the propagation route table. For details, see Modifying Enterprise Router Settings.

Creating a Propagation for an Existing Attachment

  1. Go to the enterprise router list.
  2. Search for the target enterprise router by name.
  3. Go to the Route Tables tab using either of the following methods:

    • In the upper right corner of the enterprise router, click Manage Route Table.
    • Click the enterprise router name and click Route Tables.

  4. Click the route table where you want to create a propagation. On the Propagations tab, click Create Propagation.

    The Create Propagation dialog box is displayed.

  5. Configure the parameters based on Table 1.

    Table 1 Parameters for creating a propagation

    Parameter

    Setting

    Example Value

    Attachment Type

    Mandatory

    Select an attachment type.
    • VPC: A VPC is attached to the enterprise router.
    • Virtual gateway: A Direct Connect virtual gateway is attached to the enterprise router.
    • VPN gateway: A VPN gateway is attached to the enterprise router.
    • Peering connection: The enterprise router connects to another enterprise router in a different region.
    • Global DC gateway: A Direct Connect global DC gateway is attached to the enterprise router.
    • CFW instance: A VPC border firewall is attached to the enterprise router.

    For more information, see Attachment Overview.

    VPC

    Attachment

    Mandatory

    In the drop-down list, select the attachment that will propagate routes to the route table.

    er-attach-02

    Route Policy

    Optional

    When any of the following types is selected, you can configure a route policy for the propagation of the attachment to control the routes from an attachment to the enterprise router:
    • Virtual gateway
    • VPN gateway
    • Peering connection
    • Global DC gateway

    In the Route Policy drop-down list, select a route policy.

    routePolicy-ab

  6. Click OK.

    The propagation list is displayed. You can view your propagation.