Virtual Private Cloud:Use custom route tables to manage network traffic

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. In the top navigation bar, select the region where you want to create a custom route table.

4. On the Route Tables page, click Create Route Table.

5. On the Create Route Table page, set the following parameters and click OK.

   • VPC: Select the VPC to which the custom route table belongs.

   • Associated Resource Type: Select the type of resource with which you want to associate the route table.

     • vSwitch: Controls traffic routing policies.

     • Border Gateway: Controls inbound traffic routing policies of border gateway.

   On the Route Tables page, you can view route tables classified as Custom, which is in the Route Table Type column. The following system routes are automatically added to the custom route table:

   • A route whose destination CIDR block is 100.64.0.0/10. This route is used for communication among cloud resources in the VPC.

   • A route destined for the CIDR block of all vSwitches of the VPC to which the route table belongs. This route is used for communication between cloud resources within the vSwitch.

Step 2: Add a custom route to the custom route table

1. On the Route Tables page, find the custom route table that you want to manage and click its ID.

2. On the details page, choose Route Entry List > Custom Route and click Add Route Entry.

3. In the Add Route Entry dialog box, configure the following parameters and click OK.

   Parameter	Description
   Destination CIDR Block	Enter the destination CIDR block. IPv4 CIDR Block: The destination CIDR block is an IPv4 address range. IPv6 CIDR Block: The destination CIDR block is an IPv6 address range. Note When the route table is a system route table and the associated resource is a custom route table of a vSwitch, you can set Destination CIDR Block to IPv6 CIDR Block. For more information on the available regions, see Regions that support VPC features. VPC Prefix List: The destination CIDR block is a prefix list.
   Next Hop Type	Select a next hop type. When the Destination CIDR Block is IPv4 CIDR Block or VPC Prefix List: Route the traffic directed to addresses that fall within the destination CIDR blocks to: IPv4 Gateway, NAT Gateway, VPC Peering Connection, Transit Router, VPN Gateway, ECS Instance, ENI, HaVip, Router Interface (to VBR), Router Interface (to VPC), ECR, and GWLB Endpoint. When the Destination CIDR Block is IPv6 CIDR Block: Route the traffic directed to addresses that fall within the destination CIDR blocks to: ECS Instance, IPv6 Gateway, ENI, Router Interface (to VBR), ECR, VPC Peering Connection, GWLB Endpoint and Transit Router. Note Regions where you can modify the next hop to GWLB Endpoint are supported, see Regions and zones in which Gateway Load Balancer (GWLB) is available.
   After you specify the Next Hop Type, you can select an instance as the next hop. You can also go to the product page to create an instance.

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.

1. On the Route Tables page, find the custom route table that you want to manage and click its ID.

2. On the details page of the route table, click the Associated vSwitch tab and click Associate vSwitch.

3. In the Associate vSwitch dialog box, choose the vSwitch that you want to associate.

   On the Associated vSwitch tab, click the vSwitch ID in the vSwitch column to go to the vSwitch details page. Then, click the Route tab. In the Associated with Route Table section, you can verify that the route table associated with the vSwitch is a custom route table.

Modify system route entries

You can modify the next hop of system route entries in a custom route table to direct traffic to ECS Instance or ENI for dynamic traffic management.

1. On the Route Tables page, select the desired route table instance by clicking its ID.

2. Under the Route Entry List > System Route Entries tab, locate the system route entry to modify, and click Edit in the Actions column.

3. In the Edit Route Table Entry dialog box, adjust the parameters as necessary.

   Parameter	Description
   Destination CIDR Block	Shows the destination CIDR block for traffic. The Destination CIDR Block is not modifiable.
   Next Hop Type	The next hop types include Local, ECS Instance, or Elastic Network Interface or GWLB Endpoint. Regions where you can modify the next hop to GWLB Endpoint are supported, see Regions and zones in which GWLB is available.
   After you select a Next Hop Type, you must choose a specific instance from the corresponding list or create one through the product page.

Modify custom route entries

You can modify the next hop of custom route entries to manage network traffic and direct the traffic toward specific cloud resources.

1. Navigate to the Route Tables page and click the ID of the route table you want to modify.

2. Click the Route Entry List > Custom Route tab, find the custom route entry that you want to manage, and click Edit in the Actions column.

3. In the Modify Route Table dialog box, update the following parameters:

   Parameter	Description
   Destination CIDR Block	The destination CIDR block is displayed and cannot be modified.
   Next Hop Type	Select the next hop type from the available options.
   After you select a Next Hop Type, you must then select a specific instance from the drop-down list or create a new instance on the corresponding product page.

Delete custom route entries

You can delete custom route entries in the following two ways:

• Individually: Find the custom route entry that you want to delete and click Delete in the Actions column.

• In batch: Select all the custom route entries that you want to delete and click Delete at the bottom of the page.

Delete the custom route table

On the Route Tables page, locate the custom route table to delete and click Delete in the Actions column.