The hub feature of VPN Gateway allows large-scale enterprises to connect multiple offices to each other and connect multiple offices to a virtual private cloud (VPC). This topic describes how to use the hub feature of VPN Gateway to connect multiple offices to each other and connect multiple offices to a VPC.

Overview of the hub feature

After you create a VPN gateway, the hub feature is automatically enabled. You need to only configure the customer gateway of each office and the IPsec-VPN connection from each office to the cloud. This way, the offices can communicate with each other and with the VPC.

Note You can establish at most 10 IPsec-VPN connections to a VPN gateway. You can connect ten offices in different regions to each VPN gateway.

Scenarios

Connect multiple offices

The preceding scenario is used as an example in this topic. A large enterprise has offices in Shanghai, Hangzhou, and Ningbo. The enterprise has deployed a VPC named VPC1 in the China (Hangzhou) region. Services are deployed on Elastic Compute Service (ECS) instances in VPC1. The offices cannot communicate with each other or with VPC1. Due to business development, the enterprise wants to use the hub feature of VPN Gateway to connect the offices to VPC1.

Prerequisites

  • The public IP addresses of the on-premises gateway devices in the offices are obtained.
  • VPC1 is created in the China (Hangzhou) region. Services are deployed on the ECS instances in VPC1. For more information, see Create a VPC with an IPv4 CIDR block.
    The following table describes the CIDR blocks of VPC1 and each office in this example.
    Note You can plan the CIDR blocks based on your business requirements. Make sure that the CIDR blocks do not overlap with each other.
    Office VPC1 Shanghai office Hangzhou office Ningbo office
    CIDR block to be connected 192.168.0.0/16 10.10.10.0/24 10.10.20.0/24 10.10.30.0/24
    IP address of ECS instance 192.168.20.121 N/A N/A N/A
    Public IP address of the on-premises gateway device N/A 1.XX.XX.1 2.XX.XX.2 3.XX.XX.3
  • You are aware of the security group rules that apply to the ECS instances in VPC1 and the access control rules that apply to each office. The security group rules and the access control rules allow the offices to communicate with each other and with VPC1. For more information, see Query security group rules and Add a security group rule.

Procedure

Procedure

Step 1: Create a VPN gateway

Create a VPN gateway in the region to which the VPC1 belongs. The Shanghai office, Hangzhou office, and Ningbo office use this VPN gateway to communicate with each other and with VPC1.

  1. Log on to the VPN Gateway console.
  2. In the top navigation bar, select the region where you want to create the VPN gateway.
    In this example, the China (Hangzhou) region is selected.
  3. On the VPN Gateways page, click Create VPN Gateway.
  4. On the buy page, set the following parameters, click Buy Now, and then complete the payment.
    Parameter Description
    Name Enter a name for the VPN gateway. In this example, VPN Gateway 1 is entered.
    Region Select the region where you want to deploy the VPN gateway. In this example, the China (Hangzhou) region is selected.
    VPC Select the VPC with which you want to associate the VPN gateway. In this example, VPC 1 is selected.
    Specify VSwitch Specify whether to deploy the VPN gateway in a specified vSwitch of the VPC. In this example, No is selected.
    Maximum Bandwidth Specify a maximum bandwidth value for the VPN gateway. Unit: Mbit/s.
    Traffic Select a metering method for the VPN gateway. Default value: Pay-by-data-transfer.

    For more information, see Pay-as-you-go.

    IPsec-VPN Specify whether to enable IPsec-VPN. In this example, Enable is selected.
    SSL-VPN Specify whether to enable SSL-VPN. In this example, Disable is selected.
    Duration

    Specify the billing cycle. Default value: By Hour.

    Service-linked Role Click Create Service-linked Role and the system automatically creates the service-linked role AliyunServiceRoleForVpn.

    For more information about how a VPN gateway assumes the role to access other cloud resources, see AliyunServiceRoleForVpn.

    If Created is displayed, the service-linked role is created and you do not need to create it again.

    For more information, see Create a VPN gateway.
  5. Return to the VPN Gateways page to view the VPN gateway.
    After you create a VPN gateway, it is in the Preparing state. After 1 to 5 minutes, the VPN gateway changes to the Normal state. After the VPN gateway changes to the Normal state, the VPN gateway is ready for use.

Step 2: Create a customer gateway for each office

To enable the offices to communicate with each other by using the VPN gateway, you must create a customer gateway for each office.

  1. In the left-side navigation pane, choose Interconnections > VPN > Customer Gateways.
  2. In the top navigation bar, select the region where you want to create the customer gateway.
    Note The customer gateway and the VPN gateway to be connected must be deployed in the same region.
  3. On the User Gateway page, click Create Customer Gateway.
  4. In the Create Customer Gateway panel, configure the customer gateway based on the following information and click OK:
    You must create a customer gateway for each office. For more information, see the following table.
    Parameter Description Shanghai office Hangzhou office Ningbo office
    Name Enter a name for the customer gateway. Shanghai-customer1 Hangzhou-customer2 Ningbo-customer3
    IP Address Enter the public IP address of the customer gateway. In this example, 1.XX.XX.1 is entered. This is the public IP address of the on-premises gateway device in the Shanghai office. In this example, 2.XX.XX.2 is entered. This is the public IP address of the on-premises gateway device in the Hangzhou office. In this example, 3.XX.XX.3 is entered. This is the public IP address of the on-premises gateway device in the Ningbo office.

    For more information, see Create a customer gateway.

Step 3: Create an IPsec-VPN connection for each office

Create an IPsec-VPN connection for each office to connect the offices to Alibaba Cloud.

  1. In the left-side navigation pane, choose Interconnections > VPN > IPsec Connections.
  2. In the top navigation bar, select the region of the IPsec-VPN connection.
  3. On the IPsec Connection page, click Create IPsec Connection.
  4. On the Create IPsec Connection page, set the following parameters for the IPsec-VPN connection, and click OK.
    The following table describes the configuration of the IPsec-VPN connection for each office.
    Parameter Description Shanghai office Hangzhou office Ningbo office
    Name Enter a name for the IPsec-VPN connection. IPsec-VPN Connection 1 IPsec-VPN Connection 2 IPsec-VPN Connection 3
    VPN Gateway Select the VPN gateway that you created. VPN Gateway 1
    Customer Gateway Select the customer gateway that you created. Shanghai-customer1 Hangzhou-customer2 Ningbo-customer3
    Routing Mode Select a routing mode. Destination Routing Mode Destination Routing Mode Protected Data Flows
    Local Network Enter the CIDR block to be connected to the offices. The CIDR block is used in Phase 2 negotiations. N/A N/A 192.168.0.0/16
    Remote Network Enter the CIDR block to be connected to the VPC. This CIDR block is used in Phase 2 negotiations. 10.10.30.0/24
    Effective Immediately Specify whether to immediately start negotiations for the connection.
    • Yes: starts connection negotiations after the configuration is completed.
    • No: starts negotiations when inbound traffic is detected.
    		Yes Yes Yes
    Pre-shared Key Enter a pre-shared key.

    If you do not enter a value, the system generates a random 16-character string as the pre-shared key.

    Important Make sure that the on-premises device and the IPsec-VPN connection use the same pre-shared key.
    		fddsFF123**** TTTddd321**** PPPttt456****

    Use the default settings for the other parameters. For more information, see Create and manage IPsec-VPN connections.

  5. In the Established dialog box, click OK.

Step 4: Configure routes for the VPN gateway

After you create the IPsec-VPN connections, you must add the CIDR blocks of the Shanghai and Hangzhou offices to the destination-based route table of the VPN gateway, and advertise the CIDR blocks of the Shanghai, Hangzhou, and Ningbo offices to VPC1.

Note The routing mode of the IPsec-VPN connection that you created for the Ningbo office is set to Protected Data Flows. After the IPsec-VPN connection is created, the system automatically adds the local route and the peer route to the policy-based route table of the VPN gateway. Therefore, you need to only advertise the CIDR block of the Ningbo office to VPC1 in the policy-based route table. You do not need to add a route.
  1. In the left-side navigation pane, choose Interconnections > VPN > VPN Gateways.
  2. In the top navigation bar, select the region of the VPN gateway.
  3. On the VPN Gateway page, find the VPN gateway that you want to manage and click its ID.
  4. Add and advertise the CIDR blocks of the Shanghai and Hangzhou offices on the Destination-based Routing tab of the VPN gateway.
    1. On the Destination-based Routing tab, click Add Route Entry.
    2. In the Add Route Entry panel, set the following parameters and click OK.
      Parameter Description Route 1 Route 2
      Destination CIDR Block Enter the destination CIDR block to be connected. Enter 10.10.10.0/24, the private CIDR block of the Shanghai office. Enter 10.10.20.0/24, the private CIDR block of the Hangzhou office.
      Next Hop Type Select the next hop type. Select IPsec Connection. Select IPsec Connection.
      Next Hop Select the next hop. Select IPsec-VPN Connection 1. Select IPsec-VPN Connection 2.
      Publish to VPC Specify whether to advertise the route to the route table of VPC1, the VPC that is associated with the VPN gateway. Yes is selected in this example. Yes is selected in this example.
      Weight Select a weight for the route. Valid values:
      • 100: specifies a high priority for the route.
      • 0: specifies a low priority for the route.
      		The default value 100 is used in this example. The default value 100 is used in this example.
      For more information, see Create a destination-based route.
  5. Advertise the CIDR block of the Ningbo office on the Policy-based Routing tab of the VPN gateway.
    1. On the Policy-based Routing tab, find the route whose Destination CIDR block is the CIDR block of the Ningbo office, and click Publish in the Actions column.
    2. In the Publish Route message, click OK.

Step 5: Configure the on-premises gateway devices

After you configure the VPN gateway, you must configure the on-premises gateway device of each office. You must download the configurations of the on-premises gateway devices on the IPsec Connections page and add the configurations to the on-premises gateway devices. This way, the offices can communicate with each other and with VPC1.

  1. In the left-side navigation pane, choose Interconnections > VPN > IPsec Connections.
  2. On the IPsec Connections page, find the IPsec-VPN connection that you want to manage, and choose More > Download Configuration in the Actions column.
    Find IPsec Connection 1, IPsec Connection 2, and IPsec Connection 3, and download the configurations.
  3. Add the configurations to the on-premises gateway devices. For more information, see Configure an on-premises gateway device.
    • Add the configuration downloaded from IPsec Connection 1 to the on-premises gateway device of the Shanghai office.
    • Add the configuration downloaded from IPsec Connection 2 to the on-premises gateway device of the Hangzhou office.
    • Add the configuration downloaded from IPsec Connection 3 to the on-premises gateway device of the Ningbo office.

Step 6: Test the network connectivity

After you complete the preceding configurations, the Shanghai office, Hangzhou office, Ningbo office, and VPC1 can communicate with each other. The following content describes how to test the network connectivity.

  1. Test the network connectivity between the offices and VPC1.
    1. Log on to the ECS instance that is deployed in VPC1.
      For more information about how to log on to an ECS instance, see Methods used to connect to ECS instances.
    2. Run the ping command to ping a client in each of the Shanghai office, Hangzhou office, and Ningbo office. 
      ping <the IP address of a client>

      If you can receive echo reply packets from the offices, the offices can communicate with VPC1.

  2. Test the network connectivity among the offices.
    1. Open the CLI on a client in the Shanghai office.
    2. Run the ping command to ping a client in each of the Hangzhou office and the Ningbo office. 
      ping <the IP address of a client>

      If you can receive echo reply packets from the offices, the Shanghai office can communicate with the Hangzhou office and the Ningbo office.

    3. Open the CLI on a client in the Hangzhou office.
    4. Run the ping command to ping a client in the Ningbo office. 
      ping <the IP address of a client>

      If you can receive echo reply packets from the Ningbo office, the Hangzhou office can communicate with the Ningbo office.