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Connecting an on-premises data center to a VPC via a single Direct Connect with static routing

The networks of the Virtual Private Cloud (VPC) and the on-premises data center are isolated and cannot mutually communicate. This section describes how to achieve interconnection between a data center and Elastic Compute Service (ECS) within a VPC via Direct Connect (DC) using static routes.

Prerequisites

You have created a VPC (named vpc) and its subnets. For procedure, see Creating a VPC.

tip

The subnet CIDR block of the VPC must not overlap or conflict with that of the data center. All existing route entries at the data center side must not conflict with subnet routes after being added to a DC Connection

You have created an ECS instance within vpc. For procedure, see Purchasing an ECS instance.

The data center to be interconnected has gateway devices supporting static routes.

Background

An enterprise wants its on-premises data center to access an ECS within a VPC through Direct Connect.

Data center configuration: The subnet CIDR block is 172.16.1.0/24, the interconnect IP is 10.0.0.2, and the IP address of an active server is 172.16.1.10.

VPC configuration: The subnet CIDR block is 192.168.1.0/24, the interconnect IP is 10.0.0.1, and the private IP address of the ECS is 192.168.1.10.

Procedure

Step 1: Create a DC Connection

Activate one DC Connection. For procedure, see Creating a Direct Connect Connection. In this example, the DC Connection used is DAS237_port101_conn under Project-test in China (Beijing).

Step 2: Create a DC Gateway

Click Create DC Gateway to create a DC Gateway with the following configuration.

Parameter	Description	Value
Regions	Select the region where the DC Gateway is deployed. It must match the region of the DC Connection.	China (Beijing)
Name	Set a name for the DC Gateway.	dcg-01
ASN	Set an ASN for the DC Gateway. This example does not require a custom ASN and directly uses the Volcano Engine ASN.	137718
IPv6	Enable IPv6 as needed.	Disable
Project	Select the project to which the new DC Gateway belongs.	Project-test
Agreement	Follow the console guidance to review and accept Legal.	Check

Click Buy now to complete the action.

Click Go to console to return to the Direct Connect Gateway console. You can view the new DC Gateway (dcg-01) in the DC Gateway list.

Step 3: Create a Virtual Interface

In the top menu bar, select your target region.

Click Create DC Virtual Interface.

Configure the Virtual Interface based on the table below.

Parameter	Description	Sample value
Basic information
Resource ownership	Select the account to which the Virtual Interface belongs. tip The feature of creating a Shared Virtual Interface for another account is currently in the beta stage. If you need a trial, please contact your account manager.	My account
Regions	Select the region where the Virtual Interface is deployed. It must be the same as the region of the DC Connection and the DC Gateway.	China (Beijing)
Name	Set a name for the Ethernet Virtual Interface.	VIF-uad8h
DC Connection	Filter the DC Connection by project to associate with the Virtual Interface.	Project-test\|DAS237_port101_conn
Direct Connect Gateway	Filter the DC Gateway by project to associate with the Virtual Interface.	Project-test\|dcg-01
Bandwidth limit	Enable bandwidth limit as needed.	Disable
Interconnection information
IPv4 interconnect IP	Set the IPv4 IP for interconnection. Cloud gateway peer IP: Set an IPv4 address and mask for the cloud DC gateway. You may customize the interconnect IP according to network planning, but confirm that the cloud gateway peer IP and your gateway peer IP are in the same CIDR block without duplication. Use a private IP address that does not conflict with cloud or on-premises IP addresses. Your gateway peer IP: Set an IPv4 address and mask for the gateway on your on-premises data center. You may customize the interconnect IP according to network planning, but confirm that the cloud gateway peer IP and your gateway peer IP are in the same CIDR block without duplication. Use a private IP address that does not conflict with cloud or on-premises IP addresses.	Cloud gateway IP: 10.0.0.1/30 Your gateway IP: 10.0.0.2/30
IPv6 interconnect IP	Enable IPv6 IP for interconnection as needed.	Disable
VLAN ID	Set a VLAN ID for connecting to the data center. Confirm that this VLAN ID is unoccupied.	10
Routing information
Route type	Support two route types: BGP and Static. This example uses static routes.	Static routes
Detection method	Select a detection method to check the line health.	Uncheck

Click Create to complete the action.

Step 4: Add a static route

Back to the Direct Connect Gateway console, and click the name of the target DC Gateway (dcg-01) in the DC Gateway list.

On the details page, select the Routing information tab.

Click Add static route entry, and configure the route.

Parameter	Value
Network type	IPv4
Destination CIDR	A destination CIDR block is the CIDR block of the on-premises data center that needs to communicate with the VPC. In this example, it is 172.16.1.0/24.
Next Hop type	Virtual Interface
Next Hop	VIF-uad8h

Click Add to complete configuration.

Step 5: Create a Cloud Enterprise Network

Click Create CEN.

Configure the CEN based on the table below and load vpc.

Parameter	Value
Basic information
Name	cen-test
Network Instances
Attaching a network instance	Enable
Regions	China (Beijing)
Instance type	Virtual Private Cloud (VPC)
Network Instances	Project-test\|vpc
More information
Project	Project-test

Click Create to complete the action. The ID of the new CEN is cen-rr9sri7****1hx58031.

Step 6: Load the DC Gateway to the CEN

In the list of the CEN console, click the name of the target instance (cen-test).

In the Network Instances tab, click Attach Network Instance.

The Attach Network Instance window pops up. Configure the relevant parameters

Parameter
Value
Account
My account
Regions
China (Beijing)
Instance type
Direct Connect Gateway
Network Instances
dcg-01

Step 7: Add a rule to the ECS security group

In the top menu bar, select the region: China (Beijing).

In the left-side navigation pane, click Instances. On the instance page, choose Main private IP address from the dropdown in the search box, and type 192.168.1.10 to search for the target ECS.

Click the name of the target ECS, and then click the Security Group tab.

Click the security group name. In the Access rules tab, click Add rule under the Inbound rule tab.

See the figure below to add an inbound rule that allows access from the CIDR block of the data center.

Step 8: Configure routing for the data center

In the data center, configure a route from the data center to the VPC, which means setting the destination address as the VPC and the next hop as the cloud gateway peer IP (10.0.0.1) for the route.

Log in to the on-premises gateway (the gateway IP is 10.0.0.2) and configure a route from the on-premises data center to the VPC based on the following commands.

ip route 192.168.1.0 255.255.255.0 10.0.0.1

tip

If your testing device is not the same as your on-premises gateway device, you need to configure routing between them.

Routing configuration commands may vary for gateway devices from different vendors. For specific configurations, consult your device vendor.

Step 9: Test connectivity

Test DC connectivity

In the command window of the on-premises data center, execute the ping command to ping Cloud gateway peer IP typed at the creation of the DC Gateway. In this example, ping 10.0.0.1 to verify connectivity to the DC gateway.

Test ECS connectivity

After confirming the DC communicates properly, execute the ping command in the command window of the on-premises data center, ping the IP address of an ECS within the VPC. In this example, ping 192.168.1.10 to verify connectivity to the ECS within the VPC.

Last updated: 2026.08.24 11:30:48

Parameter	Value
Account	My account
Regions	China (Beijing)
Instance type	Direct Connect Gateway
Network Instances	dcg-01