This topic describes how to configure active and standby static routes for virtual
border routers (VBRs) in the same region by using route maps of Cloud Enterprise Network
(CEN).
Prerequisites
Before you configure route maps, make sure that the following requirements are met:
Background information
Route maps accept or deny routes based on match conditions. You can configure match
conditions to modify the attributes of routes that you want to accept.
As shown in the preceding figure, an enterprise has a data center located in the China
(Hangzhou) region. The enterprise connects the data center to Alibaba Cloud by using
two Express Connect circuits from two ISPs. The port of Express Connect Circuit 1
is 10 Gbit/s, whereas the port of Express Connect Circuit 2 is 1 Gbit/s. VBR 1, VBR
2, and the virtual private cloud (VPC) are attached to the CEN instance. The enterprise
uses the Express Connect circuits to connect the data center to Alibaba Cloud through
load balancing. However, the enterprise needs to use Express Connect circuit 2 as
a standby connection because the port of Express Connect circuit 2 is slower than
that of Express Connect circuit 1. When Express Connect circuit 1 is down, network
traffic is automatically transmitted through Express Connect circuit 2.
You can add a route map with a higher priority for VBR 1 that is connected to Express
Connect circuit 1, and then add a route map with a lower priority for VBR 2 that is
connected to Express Connect circuit 2. This way, Express Connect circuit 1 functions
as the active connection and Express Connect circuit 2 functions as the standby connection.
Step 1: Set Express Connect circuit 1 that is connected to VBR 1 as the active connection
Perform the following operations to set Express Connect circuit 1 as the active connection:
- Log on to the CEN console.
- On the Instances page, find the CEN instance that you want to manage and click the ID of the instance.
- On the instance details page, find the region where you want to add a route map and
click the ID of the transit router deployed in the region.
- On the details page of the transit router, click the Route Table tab and click Route Maps.
- On the Route Maps page, click Add Route Map. Set the following parameters and click OK:
- Route Map Priority: Enter a priority value for the route map. A lower value indicates a higher priority.
In this example, 20 is entered.
- Region: Select the region to which the route map is applied. In this example, China (Hangzhou) is entered.
- Transmit Direction: Select the direction of the route map. In this example, Import to Regional Gateway is selected.
- Match Conditions: Set the match conditions of routes. In this example, set Source Instance IDs to the ID of VBR 1.
- Action Policy: Select the action that you want to perform on a route when the route meets all match
conditions. In this example, Permit is selected.
- Add Policy Entry: Set a priority value for the routes that are accepted. In this example, the priority
value is set to 10.
Note By default, the priority values of the accepted routes are 50. You can set the value
from 1 to 100. A lower value indicates a higher priority.

Step 2: Set Express Connect circuit 2 that is connected to VBR 2 as the standby connection
Perform the following operations to set Express Connect circuit 2 as the standby connection:
- In the left-side navigation pane, click Instances.
- On the Instances page, find the CEN instance that you want to manage and click the ID of the instance.
- On the instance details page, find the region where you want to add a route map and
click the ID of the transit router deployed in the region.
- On the details page of the transit router, click the Route Table tab and click Route Maps.
- On the Route Maps page, click Add Route Map. Set the following parameters and click OK:
- Route Map Priority: Enter a priority value for the route map. A lower value indicates a higher priority.
In this example, 30 is entered.
- Region: Select the region to which the route map is applied. In this example, China (Hangzhou) is entered.
- Transmit Direction: Select the direction of the route map. In this example, Import to Regional Gateway is selected.
- Match Conditions: Set the match conditions of routes. In this example, set Source Instance IDs to the ID of VBR 2.
- Action Policy: Select the action that you want to perform on a route when the route meets all match
conditions. In this example, Permit is selected.
- Add Policy Entry: Set a priority value for the routes that are accepted. In this example, the priority
value is set to 20.
Note By default, the priority values of the accepted routes are 50. You can set the value
from 1 to 100. A lower value indicates a higher priority.
