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Direct Connect

Interconnection between IDCs

Interconnecting multiple data centers via BGP-based Direct Connect

This section describes how to implement interconnection between different on-premises data centers via Direct Connect (DC) with BGP.

Prerequisites

You have enabled the feature of multi-data center interconnection via Direct Connect. The feature of multi-data center interconnection via Direct Connect is in the beta stage. If you need a trial, please contact your account manager.

You have enabled the feature of data center-bound AS Path propagation. The Direct Connect feature of data center-bound AS Path propagation is in the beta stage. If you need a trial, please contact your account manager.

All data centers to be interconnected have available DC Connections. For procedure, see Creating a Direct Connect Connection.

All data centers to be interconnected have gateway devices supporting BGP.

Precautions

Data centers intended for interconnection must have non-overlapping CIDR blocks.

We recommend assigning different ASNs for the two DC Gateways. If both DC Gateways (DCGW1 and DCGW2) use the same ASN, only a single instance of that ASN will remain in the AS Path when routing from the DC Gateway to the data center.

Background

A large enterprise has on-premises data centers in both Beijing and Shanghai, which can be connected to VolcanoEngine via DC. Then adding DC Gateways for the two DCs to the same Cloud Enterprise Network (CEN) enables network interconnection between the two data centers across regions.

Procedure

Step 1: Create a DC Connection

Deploy DC Connections in China (Beijing) and China (Shanghai) to connect respective data centers to VolcanoEngine. For procedure, see Creating a Direct Connect Connection. In this example, DAS-246-3_port1330-conn is the DC Connection in China (Beijing) and DAS-246-2_port1320-conn is the DC Connection in China (Shanghai).

Step 2: Create a DC Gateway

Click Create DC Gateway to create a DC Gateway for the Beijing data center (IDC1) with the following configuration.

Parameter	Notes	Sample value
Region	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.	DCGW1
ASN	Set an ASN for the DC Gateway. In this example, different ASNs are assigned to IDC1's and IDC2's DC Gateways. If the ASN of IDC1's DC Gateway is the same as that of IDC2's DC Gateway, only a single instance of that ASN remains in the AS Path when routing to the data center. If the ASN of IDC1's DC Gateway is different from that of IDC2's DC Gateway, both ASNs remain in the AS Path when routing to the data center.	64512
IPv6	Enable IPv6 as needed.	Disable
Project	Select the project to which the new DC Gateway belongs.	Project-test01
Protocol	Follow the console guidance to review and accept Legal.	Checked

After configuration, click Buy now to complete the creation.

Click Go to console to return to the Direct Connect Gateway console. You can view the new DC Gateway (DCGW1) in the DC Gateway list.

Repeat steps 2-4 to create a DC Gateway for the Shanghai data center (IDC2), using the parameter values listed in the table below.

Parameter	Notes	Sample value
Region	Select the region where the DC Gateway is deployed. It must match the region of the DC Connection.	China (Shanghai)
Name	Set a name for the DC Gateway.	DCGW2
ASN	Set an ASN for the DC Gateway. The ASN of IDC2's DC Gateway must be different from that of IDC1's DC Gateway.	64513
IPv6	Enable IPv6 as needed.	Disable
Project	Select the project to which the new DC Gateway belongs.	Project-test02
Protocol	Follow the console guidance to review and accept Legal.	Checked

Step 3: Create a DC Virtual Interface

Click Create DC Virtual Interface.

Configure the DC Virtual Interface based on the table below.

Parameter	Notes	Sample value
Basic Information
Virtual Interface owner	Select the account to which the DC Virtual Interface belongs. The DC Virtual Interface created in this Step is used by the current account. This parameter should be set to "My account". 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
Region	Select the region where the DC 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 DC Virtual Interface.	VIF-01
DC Connection	Filter the DC Connection by project to associate with the DC Virtual Interface.	Project-test01\|DAS-246-3_port1330-conn
DC Gateway	Filter the DC Gateway by project to associate with the DC Virtual Interface.	Project-test01\|DCGW1
Bandwidth limit	Enable bandwidth limit as needed.	Close
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 IP and your gateway 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 IP and your gateway 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 peer IP: 10.0.0.1/30 Your gateway peer 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 BGP routes.	BGP
Peer ASN	Set the ASN for the IPv4 BGP Peer. The valid range for ASN is 1 to 4294960000. The ASN of the BGP Peer can neither be the same as that of the associated DC Gateway, nor be the VolcanoEngine ASN (137718).	42949
BGP key	Type the key for the IPv4 BGP Peer.	00300
Detection method	Select a detection method to check the line health. For details, see Detection methods. In Direct Connect redundancy access mode, enabling Bidirectional Forwarding Detection (BFD) allows quick line switching when a route failure occurs. If enabling BFD control packet, you must configure BFD synchronously for your data center, confirming that Detect interval and Detect multiplier match those configured on VolcanoEngine.	BFD
BFD mode	Select a mode for the BFD detection. The mode is BFD control packet in this example.	BFD control packet
Detection Interval	The time interval for sending and receiving BFD packets.	1000
Detect multiplier	The number of detection attempts. If a session fails to receive the defined number of consecutive packets, the system declares a route failure.	3

tip

In this example, a BGP Peer is established along with the creation of the DC Virtual Interface. Once established, the BGP information (Peer ASN and BGP key) cannot be modified.

Click Create to complete the creation of the DC Virtual Interface for IDC1.

Repeat steps 2-4 to create a DC Virtual Interface for IDC2, using the parameter values listed in the table below.

Parameter	Notes	Sample value
Basic Information
Virtual Interface owner	Select the account to which the DC Virtual Interface belongs. The DC Virtual Interface created in this Step is used by the current account. This parameter should be set to "My account".	My account
Region	Select the region where the DC Virtual Interface is deployed. It must be the same as the region of the DC Connection and the DC Gateway.	China (Shanghai)
Name	Set a name for the DC Virtual Interface.	VIF-02
DC Connection	Filter the DC Connection by project to associate with the DC Virtual Interface.	Project-test02\|DAS-246-2_port1320-conn
DC Gateway	Filter the DC Gateway by project to associate with the DC Virtual Interface.	Project-test02\|DCGW2
Bandwidth limit	Enable bandwidth limit as needed.	Close
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. Your gateway peer IP: Set an IPv4 address and mask for the DC Gateway on your data center.	Cloud gateway peer IP: 10.0.0.5/30 Your gateway peer IP: 10.0.0.6/30
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 BGP routes.	BGP
Peer ASN	Set the ASN for the IPv4 BGP Peer. The valid range for ASN is 1 to 4294960000. The ASN of the BGP Peer can neither be the same as that of the associated DC Gateway, nor be the VolcanoEngine ASN (137718).	42950
BGP key	Type the key for the IPv4 BGP Peer.	00300
Detection method	Select a detection method to check the line health. For details, see Detection methods. In Direct Connect redundancy access mode, enabling Bidirectional Forwarding Detection (BFD) allows quick line switching when a route failure occurs. If enabling BFD control packet, you must configure BFD synchronously for your data center, confirming that Detect interval and Detect multiplier match those configured on VolcanoEngine.	BFD
BFD mode	Select a mode for the BFD detection. The mode is BFD control packet in this example.	BFD control packet
Detection Interval	The time interval for sending and receiving BFD packets.	1000
Detect multiplier	The number of detection attempts. If a session fails to receive the defined number of consecutive packets, the system declares a route failure.	3

Step 4: Create a CEN instance and load IDC1's DC Gateway

Click Create CEN.

Configure the CEN based on the table below, and load the DC Gateway (DCGW1).

Parameter	Sample value
Basic Information
Name	Cen-connect
Instance
Attach Network Instance	On
Region	China (Beijing)
Instance type	DC Gateway
Instance	DCGW1
More information
Project	Project-test

Click Create to complete the action.

Step 5: Load IDC2's DC Gateway to the CEN

In the CEN instances list of the CEN console, click the name of the target instance: Cen-connect.

In the Network Instances tab, click Attach Network Instance.

The Attach Network Instance window pops up. Configure the information of the DC Gateway instance to be loaded.

Parameter
Sample value
Account
My account
Region
China (Shanghai)
Instance type
DC Gateway
Instance
DCGW2

tip

If you also need to connect with a Virtual Private Cloud (VPC), just attach your target VPC to the same CEN.

Step 6: Purchase a bandwidth package and allocate inter-region bandwidth.

In this scenario, to implement intercommunication between cross-region data centers, you need to purchase a CEN bandwidth package for cross-region access. If connecting data centers in the same region, you can skip this step.

Click Create BWP, and configure the bandwidth package based on the table below.

Parameter	Sample value
Basic Information
Billing method	Subscription
Name	Package-cen
Bandwidth configuration
CEN	Project-test\|Cen-connect
Interoperability Zone	Chinese mainland - Chinese mainland
Bandwidth	300Mbps
Duration	1 month
More information
Project	Project-test

Click Confirm order, and follow the console guidance to review and accept the Legal.

Click Buy now to complete the bandwidth package creation.

In the left-side navigation pane, click CEN Instances.

Click the CEN Instance name (Cen-connect), and then click the Inter-region bandwidth tab in the details page.

In the Inter-region bandwidth tab, click Associate BWP, select the target bandwidth package (Package-cen), and click Associate.

Click Allocate inter-region bandwidth. Allocate bandwidth across regions based on the table below.

Parameter
Sample value
Bandwidth Package
Package-cen
Interconnected regions
China (Beijing) - China (Shanghai)
Bandwidth
200Mbps

Click OK to complete configuration.

Now, you have completed all the necessary configuration steps in the console.

Step 7: Configure data center routing

After completing the DC configuration in the VolcanoEngine console, you also need to configure routing for private networks of both data centers (IDC1 and IDC2). For procedure, see Configure the routing for a data center.

Step 8: Test network connectivity

Ping any IP address within 172.168.0.0/24 of IDC2. A successful response indicates that network connectivity from IDC1 to IDC2 is established.

ping 172.168.0.21

Similarly, ping the IP address of IDC1 in any server of IDC2. A successful response indicates that network connectivity from IDC2 to IDC1 is established. The interconnectivity between IDC1 and IDC2 is achieved.

Last updated: 2025.12.02 15:09:32

Parameter	Sample value
Account	My account
Region	China (Shanghai)
Instance type	DC Gateway
Instance	DCGW2

Parameter	Sample value
Bandwidth Package	Package-cen
Interconnected regions	China (Beijing) - China (Shanghai)
Bandwidth	200Mbps