Enterprise edition transit routers support custom route tables. This topic describes how to create a custom route table for an Enterprise edition transit router. After you create a custom route table, you can set associated forwarding, set route learning, and add route entries. This allows you to control the traffic forwarding of the associated network instances in a flexible way.

Prerequisites

You are using an Enterprise edition transit router. For more information about how to view the edition of transit router, see View the edition of a transit router.

Background information

An Enterprise edition transit router has a default route table and allows you to create multiple custom route tables. The default route table is isolated from custom route tables. The following content describes the default route table and custom route tables:
  • The system automatically creates the default route table. When you create a transit router instance of Enterprise edition, the system automatically creates a default route table.

    When you associate a network instance with a transit router, the system associates the network instance with the default route table. In this case, the network instance forwards traffic by querying the default route table.

  • You must manually create a custom route table. Like virtual routing and forwarding (VRF) used by traditional routers, a custom route table is isolated from the default route table and other custom route tables.

    After you create a network instance, you can set associated forwarding to associate the network instance with a custom route table. In this case, the network instance forwards traffic by querying the custom route table.

A default route table and a custom route table are created in different ways. However, they support similar features. The following table describes the features supported by a default route table and a custom route table.
Feature Description Related topic
Associated forwarding The associated forwarding feature allows you to associate a network instance with a route table. Then, the network instance forwards traffic by querying the route table. Create associated forwarding correlation
Route learning The route learning feature allows you to associate a network instance with a route table. Then, the route table automatically learns the routes of the network instance. Create route learning correlation
Route entries You can add static routes and black hole routes to a route table.

The next hop of a static route can point to a network instance.

All traffic forwarded by a black hole route is dropped.

Add route entries to a transit router
Route maps You can configure route maps to filter and modify routes. This allows you to manage network communication in the cloud.
Note You can add route maps to only the default route table.
Overview

Procedure

  1. Log on to the CEN console.
  2. On the Instances page, click the ID of the CEN instance that you want to manage.
  3. In the Transit Router section, find the transit router instance and click the instance ID.
  4. On the instance details page, click Route Table.
  5. In the left-side area, click Create Route Table and set the following parameters:
    Parameter Description
    Transit Router Select the transit router instance.
    Name Enter a name for the route table.

    The name must be 2 to 128 characters in length and can contain digits, underscores (_), and hyphens (-). It must start with a letter.

    Description Enter a description for the route table.

    The description must be 2 to 128 characters in length and can contain digits, underscores (_), and hyphens (-). It must start with a letter.

  6. Click OK.