Before you use Cloud Enterprise Network (CEN), take note of the limits in the following table.

General limits

Item Default limit Adjustable
The number of CEN instances that can be created under each Alibaba Cloud account 5

Submit a ticket

The number of bandwidth plans that you can purchase for each CEN instance when the connected areas are the same 1 N/A
The number of regions that each CEN instance supports 5

Submit a ticket

Limits on virtual private clouds (VPCs) that have ClassicLink enabled The VPCs cannot use the CIDR block 10.0.0.0/8. N/A
Network instances The network instances attached to a CEN instance cannot communicate with each other through Express Connect. N/A
Allow network instances to share NAT gateways through CEN Not supported N/A
Access cloud services across regions

For more information about cloud services, see Access cloud services through CEN.

Not supported. N/A
Allow cloud services to access the network instances attached to CEN Not supported. N/A
Subnet routing
  • VPCs learn routes of CEN instances:
    • If a VPC was attached to a CEN instance before October 22, 2019, only the system route table of the VPC learns routes from the CEN instance. To enable the custom route tables of the VPC to learn routes from the CEN instance, you must reattach the VPC to the CEN instance (service disruptions may occur) or submit a ticket.
    • If the VPC was attached to the CEN instance after October 22, 2019, all route tables of the VPC, including the system route table and custom route tables, learn routes from the CEN instance.
  • CEN instances learn routes from VPCs:

    If a VPC has multiple route tables, the CEN instance learns only the routes in the system route table of the VPC.

N/A

Limits on Enterprise edition transit routers

Item Default limit Adjustable
The number of VPCs that can be associated with each transit router 100 N/A
The number of virtual border routers (VBRs) that can be associated with each transit router 10 Submit a ticket
The number of Cloud Connect Network (CCN) instances that can be associated with each transit router 10 Submit a ticket
The number of cross-region connections supported by each transit router pair 1 N/A
The number of transit routers that can be associated with each VPC 5 N/A
The number of route tables supported by each transit router 20 N/A
The total number of route entries supported by each transit router 2,000 N/A
The maximum transit capacity supported by each transit router 100 Gbps N/A
The maximum bandwidth supported by each VPC 10 Gbps N/A

Limits on Basic edition transit routers

Item Default limit Adjustable
The number of network instances that can be associated with each transit router 10

Submit a ticket

You can increase the quota to at most 15.

The number of route entries that can be created for each CEN instance 100 Submit a ticket
The number of CCN instances that can be associated with each transit router 1 N/A