If you want to allow your on-premises network to access a cloud service, you need to connect the virtual border router (VBR), IPsec-VPN connection, or Cloud Connect Network (CCN) instance used by your on-premises network to a transit router. Then, you need to connect a virtual private cloud (VPC) in the region of the cloud service to the transit router.Virtual Private Cloud (VPC) After you connect the VPC to the transit router, your on-premises network can use the transit router to access the VPC in the region where the cloud service is deployed, and access the cloud service through the VPC. Within the same region, VPCs can access cloud services without using transit routers. If a VPC needs to access cloud services across regions, the VPC needs to connect to the transit router in the region.
Background information
Cloud services refer to the Alibaba Cloud services that use the 100.64.0.0/10 CIDR block to provide services. These cloud services include Object Storage Service (OSS), Log Service, and Data Transmission Service (DTS).
Limits
VPCs can use only Enterprise Edition transit routers to access cloud services across regions.
On-premises networks associated with IPsec-VPN connections can use only Enterprise Edition transit routers to access cloud services.
If a VBR is connected to a Basic Edition transit router, the on-premises networks connected to the VBR can use the Basic Edition transit router to access cloud services in the same region as the VBR.
For example, a VBR is deployed in the China (Beijing) region. In this case, the on-premises networks connected to the VBR can use the Basic Edition transit router to access cloud services that are also in the China (Beijing) region.
Prerequisites
The IP address or CIDR block of the cloud service is obtained. You can refer to the documentation of the cloud service to find the IP address or CIDR block.
For more information about the IP address or CIDR block of Object Storage Service (OSS), see Internal endpoints of OSS buckets and VIP ranges.
To allow an on-premises network to access cloud services:
The VBR, IPsec-VPN connection, or CCN instance used by the on-premises network is connected to the transit router. For more information, see Connect VBRs, Attach an IPsec-VPN connection to a transit router, or Associate a CCN instance with a transit router.
A VPC in the region where the cloud services are deployed is connected to the transit router. For more information, see Connect VPCs.
If the on-premises network needs to access cloud services across regions, create an inter-region connection between the transit routers. For more information, see Manage inter-region connections.
To allow a VPC to access cloud services across regions:
The VPC is connected to the transit router.
A VPC in the region where the cloud services are deployed is connected to a transit router. For more information, see Connect VPCs.
An inter-region connection is created between the transit routers in the regions. For more information, see Manage inter-region connections.
Enable access to a cloud service from an Enterprise Edition transit router
Enable access to a cloud service
Log on to the CEN console.
On the Instances page, click the ID of the CEN instance that you want to manage.
On the tab, click the ID of the transit router that resides in the region where the cloud service is deployed.
On the details page of the transit router, click the Route Table tab.
On the Route Table tab, click the ID of the route table that you want to manage in the left-side list. In the Route Table Details section, click the Route Entry tab, and then click Add Route Entry.
In the Add Route Entry dialog box, set the following parameters and click OK.
Parameter
Description
Route Table
By default, the current route table is selected.
Transit Router
By default, the current transit router is selected.
Name
Enter a name for the route entry.
Destination CIDR
Enter the IP address or CIDR block that the cloud service uses to provide services.
For example, OSS buckets in the China (Hangzhou) region use the CIDR block 100.118.28.0/24.
Blackhole Route
Select whether to specify the route as a blackhole route. Valid values:
Yes: specifies the route as a blackhole route. Traffic that matches the route is dropped.
No: specifies that the route is not a blackhole route. In this case, you must specify a next hop for the route.
No is selected in this example.
Next Hop
Select a next hop.
Select the ID of the VPC connection on the transit router.
Description
Enter a description for the route entry.
ImportantIf the cloud service uses more than one IP address or CIDR block, repeat this step to add all the IP addresses or CIDR blocks of the cloud service.
Disable access to a cloud service
Log on to the CEN console.
On the Instances page, click the ID of the CEN instance that you want to manage.
On the tab, click the ID of the transit router that resides in the region where the cloud service is deployed.
On the details page of the transit router, click the Route Table tab.
On the Route Table tab, click the route table that you want to manage in the left-side list. In the Route Table Details section, click the Route Entry tab and find the route to the cloud service.
Then, click Delete in the Actions column. In the Delete Route Entry message, click OK.
Enable access to a cloud service from an Enterprise Edition transit router by calling API operations
You can use tools such as Alibaba Cloud SDKs (recommended), Alibaba Cloud CLI, Terraform, and Resource Orchestration Service (ROS) to call API operations to add and manage routes for an Enterprise Edition transit router. For more information, see the following API references:
CreateTransitRouterRouteEntry: Adds a route to a route table of an Enterprise Edition transit router.
DeleteTransitRouterRouteEntry: Removes a static route from a route table of an Enterprise Edition transit router.
References
Enable access to a cloud service from a Basic Edition transit router
Enable access to a cloud service
Log on to the CEN console.
On the Instances page, click the ID of the CEN instance that you want to manage.
On the tab, click the ID of the transit router that resides in the region where the cloud service is deployed.
On the details page of the transit router, click the Cloud Services tab.
On the Cloud Services tab, click Configure AnyTunnel.
In the Configure AnyTunnel dialog box, configure the parameters and click OK. The following table describes the parameters.
Parameter
Description
Service IP Address
Enter the IP address or CIDR block that the cloud service uses to provide services, for example, 100.118.28.0/24.
Service Region
Select the region where the cloud service is deployed.
Service VPC
Select the VPC that is connected to the transit router.
Access Region
Select the region where the VBR or CCN instance that needs to access the cloud service is deployed.
Description
Enter a description for the cloud service.
ImportantIf the cloud service uses more than one IP address or CIDR block, repeat this step to add all the IP addresses or CIDR blocks of the cloud service.
Disable access to a cloud service
Log on to the CEN console.
On the Instances page, click the ID of the CEN instance that you want to manage.
On the tab, click the ID of the transit router that resides in the region where the cloud service is deployed.
On the details page of the transit router, click the Cloud Services tab.
On the Cloud Services tab, find the cloud service that you want to manage and click Delete in the Actions column.
In the Delete Route Service message, click OK.
Enable access to a cloud service from a Basic Edition transit router by calling API operations
You can use tools such as Alibaba Cloud SDKs (recommended), Alibaba Cloud CLI, Terraform, and Resource Orchestration Service (ROS) to call API operations to add and manage routes for a Basic Edition transit router. For more information, see the following API references:
ResolveAndRouteServiceInCen: Connects an on-premises network to a cloud service.
DescribeRouteServicesInCen: Queries the cloud services that are configured on a Cloud Enterprise Network (CEN) instance.
DeleteRouteServiceInCen: Deletes the configuration of a cloud service.
FAQ
After I configure access to cloud services in the Alibaba Cloud Management Console, why does the on-premises network fail to access cloud services?
After you configure access to cloud services in the Alibaba Cloud Management Console, you must add routes that point to the cloud services in your on-premises network. Check whether you have added such routes in your on-premises network.