Virtual Private Cloud:Create and manage an IPv4 gateway

Prerequisites

A VPC and a vSwitch are created. For more information, see Create and manage a VPC and Create and manage a vSwitch.

Manage Internet access

After you create and activate an IPv4 gateway, you can select a primary route table or a subnet route table. The system automatically adds a default 0.0.0.0/0 route to the IPv4 gateway. This way, instances in the vSwitch associated with the route table can access the Internet through the IPv4 gateway.

Create and activate an IPv4 gateway

1. Log on to the VPC console.

2. In the top navigation bar, select the region where you want to create an IPv4 gateway.

3. In the left-side navigation pane, click IPv4 Gateway.

4. On the IPv4 Gateway page, click Create IPv4 Gateway.

5. Configure the parameters in the Create IPv4 Gateway dialog box. Then, activate the IPv4 gateway and add a route that points to the IPv4 gateway.

   1. Create an IPv4 gateway

      In the Create IPv4 Gateway wizard, configure the following parameters. Keep parameters not covered as default values or modify them as needed.

      Parameter	Description
      Region	The region where you want to create the IPv4 gateway is displayed.
      VPC	Select the VPC with which you want to associate the IPv4 gateway.

   2. Activate the IPv4 gateway

      In the Activate IPv4 Gateway wizard, select one or more route tables and click Activate.

      Note

      • We recommend that you select a route table associated with a vSwitch that contains public IP addresses and NAT gateways.

      • After you select a route table, the system automatically adds a default 0.0.0.0/0 route that points to the IPv4 gateway. This way, the vSwitch associated with the route table can access the Internet.

      • If a default 0.0.0.0/0 route already exists in the route table, the preceding route will not be added. If the vSwitch associated with the route table requires Internet access, we recommend that you plan the routes in advance.

(Optional) Manage inbound routing policies

After you create and activate an IPv4 gateway, you can create a gateway route table and associate it with the IPv4 gateway. This way, Internet traffic can be routed to the VPC.

Step 1: Create a gateway route table and modify routes

A route table associated with an IPv4 gateway is referred to as a gateway route table. You can modify routes to control traffic from the IPv4 gateway to the VPC. You can create only one gateway route table in a VPC.

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

2. On the Create Route Table page, set the following parameters. Keep other parameters as their default values or modify them as needed.

   Parameter	Description
   VPC	Select the VPC to which the route table belongs. In this example, the VPC to which the IPv4 gateway belongs is selected.
   Associated Resource Type	Select the type of the resource with which you want to associate the route table. vSwitch: The route table is associated with a vSwitch. In this case, the route table serves as a custom route table and is used to manage traffic within the vSwitch. Border Gateway: The route table is associated with an IPv4 gateway. In this case, the route table serves as a gateway route table and is used to control traffic from the IPv4 gateway to the VPC. In this example, Border Gateway is selected.

3. On the Route Tables page, find the gateway route table and click its ID.

4. On the Route Entry List > System Route tab, find the system route that you want to modify and click Edit in the Actions column.

5. In the Edit Route Entry dialog box, set the following parameters. Keep other parameters as their default values or modify them as needed.

   Parameter	Description
   Destination CIDR Block	Displays the destination CIDR block of traffic. You cannot modify Destination CIDR Block.
   Next Hop Type	Select the next hop type. Valid values: Local: Traffic destined for the destination CIDR block is routed to the VPC. ECS Instance: Traffic destined for the destination CIDR block is routed to the specified ECS instance. ENI: Traffic destined for the destination CIDR block is routed to the specified elastic network interface (ENI). Important If the next hop type is set to ENI or ECS Instance, you must first change the next hop type to Local, change the next hop type to ENI or ECS Instance, and then change the next hop. You cannot directly change the next hop when the next hop type is set to ENI or ECS Instance.
   Resource Group	Select the resource group to which the next hop belongs. If Next Hop Type is set to ECS Instance or ENI, this parameter is required.
   ECS Instance or ENI	Select an instance as the next hop. If Next Hop Type is set to ECS Instance or ENI, you must select an instance as the next hop.

Step 2: Associate the gateway route table with an IPv4 gateway

After the gateway route table is created, associate it with an IPv4 gateway. Then, you can configure routes to manage traffic from the IPv4 gateway to the VPC. Before you associate the gateway route table with an IPv4 gateway, make sure that an IPv4 gateway is created and activated. For more information, see Manage Internet access.

1. On the IPv4 Gateway page, find the IPv4 gateway that you want to manage and click its ID.

2. On the details page of the IPv4 gateway, click Bind on the Gateway Route Entry tab.

3. In the Associate Route Table dialog box, confirm the gateway route table and click OK.

4. After the route table is associated with the IPv4 gateway, Internet traffic is routed to instances as expected based on the configured routes. You can control Internet access and ensure security.

Disassociate a gateway route table from an IPv4 gateway

If you no longer need to route Internet traffic to a VPC, you can disassociate the gateway route table from the IPv4 gateway.

1. In the left-side navigation pane, click IPv4 Gateway.

2. On the IPv4 Gateway page, find the IPv4 gateway that you want to manage and click its ID.

3. On the details page of the IPv4 gateway, click Unbind on the Gateway Route Entry tab.

4. In the message that appears, click OK.

Delete an IPv4 gateway

You can delete an IPv4 gateway in one of the following modes:

Private Mode: After the IPv4 gateway is deleted, instances in the VPC cannot access the Internet.

Public Mode: After the IPv4 gateway is deleted, instances that are assigned public IP addresses in the VPC can access the Internet.

Before you delete an IPv4 gateway:

• If the IPv4 gateway is associated with a gateway route table, disassociate the gateway route table from the IPv4 gateway. For more information, see Disassociate a gateway route table from an IPv4 gateway.

• If you select Private Mode, you must first all the routes that point to IPv4 gateway from VPC route tables. For more information, see Add and delete routes.

• If you select Public Mode, the system automatically deletes all the routes that point to the IPv4 gateway.

1. Log on to the VPC console.

2. In the top navigation bar, select the region where the IPv4 gateway is deployed.

3. In the left-side navigation pane, click IPv4 Gateway.

4. On the IPv4 Gateway page, find the IPv4 gateway that you want to delete and click Delete in the Actions column.

5. In the dialog box that appears, select a deletion mode and click OK.

   • Private Mode: After the IPv4 gateway is deleted, instances in the VPC cannot access the Internet.

   • Public Mode: After the IPv4 gateway is deleted, instances that are assigned public IP addresses in the VPC can access the Internet.

   Important

   If the VPC requires Internet access after you delete the IPv4 gateway in Private Mode, create a new IPv4 gateway in the VPC and configure routes that point to the IPv4 gateway.

More operations