Transit routers are core components of Cloud Enterprise Network (CEN). Transit routers provide multiple network communication and route management features. For example, you can use transit routers to connect network instances, create custom route tables, add route entries, and add route maps. This topic describes the features supported by transit routers.

Transit routers and related resources

A CEN instance creates a transit router instance in each region. Each transit router instance represents a transit router. You can use a transit router to connect network instances deployed in the current region to network instances that are deployed in the same region or different regions. Transit routers support intra-region route tables, route maps, and cross-region connections to meet your business requirements.

The following content describes the related resources when you use a transit router.

Transit routers and related resources
Related resource Description Note
CEN instances A CEN instance represents a network that covers one or multiple regions.

Each CEN instance contains two or more transit routers. You can purchase bandwidth plans to allow transit routers in different regions to communicate with each other. This builds a cross-region network.

N/A
Transit router instances Each transit router instance represents a transit router.

You can create a transit router for a CEN instance in each region.

N/A
Transit router connections Transit router connections refer to the connections between transit routers and network instances. You can create a connection between a transit router and a network instance that are deployed in the same or different regions.
  • Connect to network instances in the same region: You can create a connection between a transit router and a network instance that are deployed in the same region.

    The following network instance types are supported:

    • Virtual private clouds (VPCs)
    • Virtual border routers (VBRs)
    • Cloud Connect Network (CCN) instances
  • Connect to network instances across regions: You can create a connection between a transit router and a network instance that are deployed in different regions.

    Network instances deployed in different regions can communicate with each other through transit routers.

N/A
Route tables of a transit router Network instances that are attached to a CEN instance forward traffic by querying the route tables of the transit router in the current region.
Each transit router has a default route table. You can also create custom route tables for each transit router.
  • Default route table: The system automatically creates a default route table when you create a transit router instance.
  • Custom route table: You can manually create custom route tables.

The default route table of a transit router is isolated from its custom route tables.

  • Each Basic Edition transit router has one default route table and does not support custom route tables.
  • Each Enterprise Edition transit router has one default route table and supports custom route tables.

Features

Transit routers provide multiple network communication and route management features. For example, you can use transit routers to connect network instances, create custom route tables, add route entries, and add route maps.

Transit routers are provided with two editions based on regions: the basic edition and the enterprise edition. Basic Edition transit routers and Enterprise Edition transit routers have different features. For more information, see the following table. For more information about the regions that support Enterprise Edition transit routers, see Regions and zones that support Enterprise Edition transit routers.

Feature type Feature Basic Edition Enterprise Edition References
Basic features Create transit router instances Not supported

When you create a transit router connection in a region, the system automatically creates a transit router instance in the region. You cannot manually create transit router instances.

Supported Create a transit router
Create transit router connections Supported Supported
Routing Create custom route tables Not supported

Each Basic Edition transit router has only one default route table. All network instances that are associated with the transit router forward traffic by querying the default route table.

Supported Overview
Add route entries Not supported Supported
Configure associated forwarding Not supported Supported
Configure route learning Not supported Supported
Add route maps Supported Supported
Cloud services Configure access to cloud services Supported Supported Enable access to cloud services
Configure PrivateZone Supported Supported Configure PrivateZone

Regions and zones that support Enterprise Edition transit routers

Transit routers are provided with two editions based on regions: the basic edition and the enterprise edition. The following table describes the regions and zones that support Enterprise Edition transit routers. By default, regions and zones that are not included in the following table support Basic Edition transit routers.

Area Region Zone
Mainland China China (Hangzhou) Zone H and Zone I
China (Shenzhen) Zone D and Zone E
China (Beijing) Zone H and Zone G
China (Shanghai) Zone F and Zone G
Asia Pacific Singapore (Singapore) Zone B and Zone C
China (Hong Kong) Zone B and Zone C
North America US (Virginia) Zone A and Zone B
US (Silicon Valley) Zone A and Zone B