You can create a custom route table for a virtual private cloud (VPC) and add subnet routes to the custom route table. Then, you can associate the custom route table with a vSwitch to manage the traffic of the vSwitch. This facilitates network management.

Prerequisites

A VPC is created. For more information, see Create a VPC.

Background

Before you add subnet routes to a custom route table, take note of the following limits:

  • Each VPC can contain at most 10 route tables including the system route table.
  • Each vSwitch can be associated with only one system route table or one custom route table.
  • Custom route tables do not support active or standby routes, or load-balancing routes.

Step 1: Create a custom route table

  1. Log on to the VPC console.
  2. In the left-side navigation pane, click Route Tables.
  3. Select the region where you want to create a custom route table.
    For more information about regions that support custom route tables, see Regions that support custom route tables.
  4. On the Route Tables page, click Create Route Table.
  5. In the Create Route Table dialog box, set the following parameters and click OK.
    Parameter Description
    Resource Group Select the resource group to which the route table belongs.
    VPC Select the VPC to which the route table belongs.

    If a VPC contains an Elastic Compute Service (ECS) instance that belongs to one of the following instance families, you cannot create a custom route table for the VPC.

    ecs.c1, ecs.c2, ecs.c4, ecs.ce4, ecs.cm4, ecs.d1, ecs.e3, ecs.e4, ecs.ga1, ecs.gn4, ecs.gn5, ecs.i1, ecs.m1, ecs.m2, ecs.mn4, ecs.n1, ecs.n2, ecs.n4, ecs.s1, ecs.s2, ecs.s3, ecs.se1, ecs.sn1, ecs.sn2, ecs.t1, and ecs.xn4.

    To create a custom route table, you must upgrade or release ECS instances that do not support advanced VPC features.
    Note If your VPC contains ECS instances of the preceding instance families and a custom route table is created, you must upgrade or release the instance. Otherwise, the custom route table cannot work as expected. For more information, see Overview of VPC advanced features.
    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 256 characters in length and cannot start with http:// or https://.

    After you create custom route tables, you can go to the Route Tables page to view route tables whose Route Table Type is Custom.The following system route entries are automatically added to custom route tables:
    • A route destined for the CIDR block 100.64.0.0/10. This route is used for communication between cloud resources within the VPC.
    • A route destined for the CIDR block of a vSwitch of the VPC to which the route table belongs. This route is used for communication between cloud resources within the vSwitch.
    For example, you have created two vSwitches whose CIDR blocks are 192.168.1.0/24 and 192.168.0.0/24. These vSwitches are deployed in the VPC whose CIDR block is 192.168.0.0/16. Custom route tables that you create for the VPC include the following route entries:
    Destination CIDR block Next hop Type
    100.64.0.0/10 - System route
    192.168.1.0/24 - System route
    192.168.0.0/24 - System route

Step 2: Add subnet routes

Step 3: Associate the custom route table with a vSwitch

You can associate the custom route table with a vSwitch to manage the routes of the vSwitch. Each vSwitch can be associated with only one system route table or one custom route table. Perform the following operations to associate the custom route table with a vSwitch.

  1. Log on to the VPC console.
  2. In the left-side navigation pane, click Route Tables.
  3. In the top navigation bar, select the region to which the route table belongs.
    For more information about the regions that support custom route tables, see Regions that support custom route tables.
  4. On the Route Tables page, find the route table and click its ID.
  5. In the Route Table Details section, click the Associated vSwitch tab and click Associate vSwitch.
  6. On the Associate vSwitch page, select the vSwitch that you want to associate and click OK.