This topic describes how to use IPsec-VPN to establish a secure connection between two virtual private clouds (VPCs). This way, the cloud resources in one VPC can access the cloud resources in the other VPC.
Scenarios
VPN gateways do not support cross-border connections. When you create an IPsec-VPN connection between two VPCs, both the VPCs must be in the Chinese mainland or outside the Chinese mainland. For more information about the regions that are in the Chinese mainland or outside the Chinese mainland, see Intra-border connections.
If you want to create a connection between a VPC in the Chinese mainland and a VPC outside the Chinese mainland, we recommend that you use the Cloud Enterprise Network (CEN) service. For more information, see What is CEN?
If you create an IPsec-VPN connection between two VPCs that are in different regions, the IPsec-VPN connection quality is determined by the Internet connection quality. In this case, we recommend that you use CEN to connect the VPCs. For more information, see Use Enterprise Edition transit routers to connect VPCs across regions and accounts.
The following scenario is used as an example in this topic: An enterprise created a VPC named VPC 1 in the China (Hangzhou) region and another VPC named VPC 2 in the China (Qingdao) region. Elastic Compute Service (ECS) instances are deployed in the VPCs, and services are deployed on the ECS instances. Due to business development, the services in VPC 1 and VPC 2 need to communicate with each other.
To ensure network security, the enterprise decides to use VPN gateways to establish an IPsec-VPN connection between VPC 1 and VPC 2. This way, data transmission between the VPCs is encrypted and the cloud resources can communicate with each other over secure connections.
Prerequisites
The following scenario is used as an example in this topic: An enterprise created a VPC named VPC 1 in the China (Hangzhou) region and another VPC named VPC 2 in the China (Qingdao) region. Elastic Compute Service (ECS) instances are deployed in the VPCs, and services are deployed on the ECS instances. For more information, see Create an IPv4 VPC.
The following table describes the configurations of VPC 1 and VPC 2 in this example.
ImportantYou can specify the CIDR blocks based on your business requirements. Make sure that the CIDR blocks that need to communicate do not overlap.
VPC name
Region
VPC CIDR block
VPC ID
ECS instance name
ECS instance IP address
VPC1
China (Hangzhou)
192.168.0.0/16
vpc-bp1e0yx3nsosmitth****
ECS1
192.168.20.161
VPC2
China (Qingdao)
10.0.0.0/16
vpc-m5e83sapxp88cgp5f****
ECS2
10.0.1.110
You understand the security group rules that apply to the ECS instances in the VPCs. Make sure that the security group rules allow the ECS instances to communicate with each other. For more information, see View security group rules and Add a security group rule.
Procedure
Step 1: Create a VPN gateway
Log on to the VPN Gateway console.
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.
NoteThe VPN gateway must belong to the same region as the VPC that you want to associate with the VPN gateway.
On the VPN Gateways page, click Create VPN Gateway.
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.
Gateway Type
Select a VPN gateway type. In this example, Standard is selected.
Network Type
Select the network type of the VPN gateway. In this example, Public is selected.
Tunnels
The supported tunnel modes are automatically displayed.
VPC
Select the VPC with which you want to associate the VPN gateway. In this example, VPC 1 is selected.
VSwitch
Select a vSwitch from the selected VPC.
If you select Single-tunnel, you need to specify only one vSwitch.
If you select Dual-tunnel, you need to specify two vSwitches.
After the IPsec-VPN feature is enabled, the system creates an elastic network interface (ENI) for each of the two vSwitches as an interface to communicate with the VPC over an IPsec-VPN connection. Each ENI occupies one IP address in the vSwitch.
NoteBy default, the system selects a vSwitch. You can change or use the default vSwitch.
After a VPN gateway is created, you cannot modify the vSwitch associated with the VPN gateway. You can view the vSwitch associated with the VPN gateway, the zone to which the vSwitch belongs, and the ENI in the vSwitch on the details page of the VPN gateway.
vSwitch 2
Select another vSwitch from the selected VPC.
Ignore this parameter if you select Single-tunnel.
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 Billing.
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
Select a billing cycle. Default value: By Hour.
Service-linked Role
Click Create Service-linked Role. Then, the system automatically creates the service-linked role AliyunServiceRoleForVpn.
The VPN gateway assumes this role to access other cloud resources. For more information, see AliyunServiceRoleForVpn.
If Created is displayed, it indicates that the service-linked role is created and you do not need to create it again.
For more information, see Create a VPN gateway.
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.
Repeat Substep2 to Substep4 of Step 1 to create a VPN gateway named VPN Gateway 2 in the China (Qingdao) region. Specify VPC 2 for the VPC parameter. Specify the same values as VPN Gateway 1 for the other parameters.
The following table describes the information about the VPN gateways that are created in this example.
Region
VPN gateway name
VPC name
VPN gateway ID
VPN gateway IP address
China (Hangzhou)
VPN Gateway 1
VPC1
vpn-bp1l5zihic47jprwa****
120.XX.XX.40
China (Qingdao)
VPN Gateway 2
VPC2
vpn-m5eqjnr4ii6jajpms****
118.XX.XX.20
Step 2: Create a customer gateway
In the left-side navigation pane, choose .
In the top navigation bar, select the region of the customer gateway.
NoteMake sure that the customer gateway and the VPN gateway to be connected are deployed in the same region.
On the Customer Gateway page, click Create Customer Gateway.
In the Create Customer Gateway panel, set the following parameters and click OK.
You must create a customer gateway in the China (Hangzhou) region and the China (Qingdao) region. The following table describes the parameters of the customer gateways.
Parameter
Description
China (Hangzhou)
China (Qingdao)
Name
Enter a name for the customer gateway.
Customer1
Customer2
IP Address
Enter the public IP address of the customer gateway.
In this example, the IP address of VPN Gateway 2, 118.XX.XX.XX. 20, is entered
NoteIn this example, VPN Gateway 1 is the customer gateway of VPC 2, and VPN Gateway 2 is the customer gateway of VPC 1.
In this example, the IP address of VPN Gateway 1, 120.XX.XX.40, is entered
For more information, see Create a customer gateway.
The following table describes the information about the VPN gateway, customer gateway, and VPC in each region.
Region
VPC name
VPN gateway name
Customer gateway name
Customer gateway ID
Customer gateway IP address
China (Hangzhou)
VPC1
VPN Gateway 1
Customer1
cgw-bp1er5cw26c2b35vm****
118.XX.XX.20
China (Qingdao)
VPC2
VPN Gateway 2
Customer2
cgw-m5e6qdvuxquse3fvm****
120.XX.XX.40
Step 3: Create an IPsec-VPN connection
After you create the VPN gateways and customer gateways, you can create IPsec-VPN connections to connect the VPN gateways to the customer gateways.
In the left-side navigation pane, choose .
In the top navigation bar, select the region in which the IPsec-VPN connection resides.
On the IPsec Connections page, click Create IPsec-VPN Connection.
On the Create IPsec-VPN Connection page, set the parameters for the IPsec-VPN connection, and click OK.
You must create an IPsec-VPN connection in the China (Hangzhou) region and another IPsec-VPN connection in the China (Qingdao) region. The following table describes the parameters of the IPsec-VPN connections.
Parameter
Description
China (Hangzhou)
China (Qingdao)
Name
Enter a name for the IPsec-VPN connection.
IPsec-VPN Connection 1
IPsec-VPN Connection 2
VPN Gateway
Select the VPN gateway that you created.
VPN Gateway 1
VPN Gateway 2
Customer Gateway
Select the customer gateway that you created.
Customer1
Customer2
Routing Mode
Select a routing mode.
Select Destination Routing Mode.
Select Destination Routing Mode.
Effective Immediately
Specify whether to immediately start negotiations.
If you set the Effective Immediately parameter to Yes when you create an IPsec-VPN connection, the negotiations immediately start after the configuration is complete.
If you set the Effective Immediately parameter to No when you create an IPsec-VPN connection, the negotiations start when inbound traffic is detected.
NoteIf you use a VPN gateway to create IPsec-VPN connections between two VPCs, we recommend that you set Effective Immediately to Yes for one IPsec-VPN connection. This way, IPsec negotiations can be immediately started.
In this example, No is selected.
Yes is selected in this example.
Pre-Shared Key
Enter a pre-shared key.
The key must be 1 to 100 characters in length, and can contain digits, letters, and the following special characters:
~ ` ! @ # $ % ^ & * ( ) _ - + = { } [ ] \ | ; : ' , . < > / ?If you do not specify a pre-shared key, the system generates a random 16-character string as the pre-shared key. After an IPsec-VPN connection is created, you can click Edit in the Actions column to view the pre-shared key that is generated for the IPsec-VPN connection. For more information, see the Modify an IPsec-VPN connection section of the "Create and manage IPsec-VPN connections in single-tunnel mode" topic.
ImportantThe pre-shared key configured for the IPsec-VPN connection and the peer gateway device must be the same. Otherwise, the system cannot establish an IPsec-VPN connection.
fddsFF123****
Use the default settings for the other parameters. For more information, see Create and manage an IPsec-VPN connection in single-tunnel mode.
In the Created dialog box, click OK.
Step 4: Configure routes
In the left-side navigation pane, choose .
In the top navigation bar, select the region in which the VPN gateway resides.
On the VPN Gateway page, find the VPN gateway that you want to manage and click its ID.
On the Destination-based Route Table tab, click Add Route Entry.
In the Add Route Entry panel, set the following parameters and click OK.
You must add a route to VPN Gateway 1 and VPN Gateway 2. The following table describes the parameters of routes.
Parameter
Description
VPN Gateway1
VPN Gateway 2
Destination CIDR Block
Enter the destination CIDR block.
Enter 10.0.0.0/16, which is the private CIDR block of VPC 2.
Enter 192.168.0.0/16, which is the private CIDR block of VPC 1.
Next Hop Type
Select the next hop type.
Select IPsec Connection.
Select IPsec Connection.
Next Hop
Select a next hop.
In this example, IPsec-VPN Connection 1 is selected.
In this example, IPsec-VPN Connection 2 is selected.
Publish to VPC
Specify whether to advertise the route to 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.
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 Add a destination-based route.
Step 5: Test the network connectivity
Log on to ECS1 in VPC1.
For more information about how to log on to an ECS instance, see Guidelines on instance connection.
Run the ping command to ping the IP address of ECS 2 to test network connectivity.
ping <IP address of ECS 2>If you can receive echo reply packets as shown in the following figure, the VPCs can communicate with each other.
