Updated on 2024-05-20 GMT+08:00

Route Overview

What Is a Route?

Routes are used to forward packets. A route contains information such as the destination, next hop, and route type.

You can create a propagation for attachments to automatically propagate routes to route tables or manually add static routes to route tables.

Figure 1 Propagated routes and static routes
Table 1 Route types

Route Type

Description

Attachment Type

How to Create

Description

Propagated routes

Propagated routes are routes that attachments propagate to the route tables of the enterprise router. They cannot be modified or deleted.

  • VPC
  • Virtual gateway
  • Peering connection
  • VPN gateway
  • Global DC gateway
  • CFW instance

To create a propagation, see Creating a Propagation for an Attachment in the Route Table.

Routes are classified into propagated routes and static routes. The routes shown in Figure 1 are described as follows:
  • Propagated routes are from:
    • Propagations automatically created in the default route table of the enterprise router for attachments, such as peering connection 2, virtual gateway 1, VPN gateway 1, and VPC 1 attachments.
    • Propagations manually created 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.
  • Static routes are manually added to the custom route table of the enterprise router for attachments, such as VPC 2 and peering connection 3 attachments.

Static routes

Static routes are manually created and can be modified or deleted.

Static routes include common routes and blackhole routes. A blackhole route only has a destination and has no next hop. It drops all traffic sent to the specified destination.

  • VPC
  • Peering connection
  • CFW instance

To create a route, see Creating a Static Route.

Route Priority

If there are multiple routes with the same destination but different targets in a route table, the route priority is as follows:

Static route > Propagated route for VPC attachment = Propagated route for CFW instance attachment > Propagated route for virtual gateway attachment = Propagated route for global DC gateway attachment > Propagated route for VPN gateway attachment > Propagated route for peering connection attachment

  • Static routes are manually configured and the destination of each static route must be unique in a route table.
  • Propagated routes are automatically learned by the system and may have the same destination in a route table.
  • A static route and a propagated route may have the same destination in a route table.