Notes and Constraints

Cloud Connect Constraints

Note the following constraints when you are using Cloud Connect for network communication.

Cloud Connection Constraints

Cross-Border Permit Constraints

Network Instance Constraints

Bandwidth Package Constraints

Inter-Region Bandwidth Constraints

Cross-Account Authorization Constraints

Route Constraints

Central Network Constraints

Global Connection Bandwidth Constraints

A cloud connection cannot be created between VPCs that have overlapping CIDR blocks, or communication will fail.
If you load a VPC to a cloud connection created using the same account, you cannot enter loopback addresses, multicast addresses, or broadcast addresses for the custom CIDR block.
If a NAT gateway has been created for any VPC you have loaded to a cloud connection, a custom CIDR block needs to be added and set to 0.0.0.0/0.
Multiple bandwidth packages can be bound to a cloud connection only when their billing modes are different.
A cloud connection can only have one bandwidth package bound if the geographic regions and billing mode of the bandwidth packages are the same.

To use a central network, the following resources must have been created:
- Enterprise router: used to build a central network
- Global DC gateway: attached to an enterprise router for allowing on-premises data centers to access the cloud across regions
Policy management
- A central network can only have one policy. If you apply another policy for this central network, the policy that was previously applied will be automatically cancelled.
- In each policy, only one enterprise router can be added for a region. All added enterprise routers can communicate with each other by default.
- A policy that is being applied or cancelled cannot be deleted.
Cross-site connection bandwidth management
- A cross-site connection bandwidth cannot be changed or deleted when it is being created, updated, deleted, frozen, unfrozen, or is recovering.
- The total of cross-site connection bandwidths cannot exceed the global connection bandwidth.
- If a cross-site connection bandwidth is deleted, you will still be billed for the global connection bandwidth.

Cloud Connect Resource Quotas

A quota defines the maximum number of resources of a certain type that can be created in a region or account.

For example, an account can create six central networks by default. If two central networks have been created in the account, four more central networks can be created.

To help you save quotas, there are limits on the maximum number of cloud resources that you can create in each region or account.

You can log in to the console to view the default quotas for each resource. To increase the resource quota, you can refer to Applying for a Higher Quota.

Table 1 and Table 2 describe the default quotas of cloud connections and central networks.

**Table 1** Cloud connection quotas
Item	Default Quota	Adjustable
Cloud connections allowed in each account	6	Yes Submit a service ticket.
Regions per cloud connection	6	Yes Submit a service ticket.
Network instances allowed in each region	6	Yes For cross-region communication, the quota can be increased to 10. Submit a service ticket.
Bandwidth packages for each cloud connection	1	No
Routes per cloud connection	50	Yes Submit a service ticket.

**Table 2** Central network quotas
Item	Default Quota	Adjustable
Central networks in an account	6	Yes Submit a service ticket.
Policies for a central network	500	Yes Submit a service ticket.
Policy document size (KB)	10	No
Enterprise routers on a central network as attachments in a region	1	No
Global DC gateways on a central network as attachments in a region	3	Yes Submit a service ticket.