After you create a virtual border router (VBR), the system automatically creates a route table for the VBR. Add routes to the route table to control where network traffic is forwarded between your data center and Alibaba Cloud.
How it works
VBRs support three types of routes:
Custom routes: Static routes you add manually to direct traffic to a VPC or an Express Connect circuit. Each VBR supports up to 48 custom routes.
BGP routes: Dynamic routes exchanged with your on-premises router using Border Gateway Protocol (BGP). For configuration steps, see Configure and manage BGP.
CEN routes: Routes automatically learned between the VBR and a Cloud Enterprise Network (CEN) instance once the VBR is attached.
VBRs do not support source address-specific policy-based routing.
Prerequisites
Before you begin, ensure that you have:
A VBR created in the Express Connect console
The CIDR block of the destination network (for example, your on-premises data center subnet or VPC CIDR block)
The next hop resource ready: a VPC or an Express Connect circuit
(For IPv6 routes) A VBR with IPv6 support enabled, and the IPv6 CIDR block to route (excluding
2403:28c0:200::/40)
After you create a VBR, you must add routes that point to the Express Connect circuit and the VPC to route network traffic to the data center and the VPC.
To access internal Object Storage Service (OSS) endpoints using CEN, Express Connect, Smart Access Gateway (SAG), or Virtual Private Network (VPN), add routes pointing to the CIDR blocks of the regions where the OSS endpoints are located. For region-to-CIDR block mapping, see Regions and endpoints.
Add a custom route
Log on to the Express Connect console.
In the top navigation bar, select a region, then click Virtual Border Routers (VBRs) in the left-side navigation pane.
On the Virtual Border Routers (VBRs) page, find the VBR and click its ID.
Click the Routes tab, then click Add Route.
In the Add Route panel, configure the following parameters and click OK.
| Parameter | Description |
|---|---|
| Network type | The IP version of the route. Select IPv4 Routing for IPv4 routes or IPv6 Routing for IPv6 routes. This parameter is required only when the VBR supports IPv6. |
| Next hop type | The resource that receives traffic for the destination CIDR block. Select VPC to route traffic to a virtual private cloud (VPC), or Physical Connection Interface to route traffic to an Express Connect circuit. |
| Destination CIDR block | The destination CIDR block that the route matches. For IPv6 routes, all IPv6 CIDR blocks are valid except 2403:28c0:200::/40. |
| Next hop | The specific VPC or Express Connect circuit to forward matching traffic to. The available options depend on the Next hop type selected. |
| Description | A description for the route. |
If the VBR is associated with an Enterprise Edition transit router and you need a static route pointing to that transit router, do not add the route here. Instead, go to the Network Routes tab of the transit router, select the VBR, and click Add Route Entry. For details, see Configure a route for a network instance.
Delete a custom route
Log on to the Express Connect console.
In the top navigation bar, select a region, then click Virtual Border Routers (VBRs) in the left-side navigation pane.
On the Virtual Border Routers (VBRs) page, find the VBR and click its ID.
Click the Routes tab, find the route to delete, and click Delete in the Actions column.
In the confirmation dialog, click OK.
API reference
| API operation | Description |
|---|---|
| CreateRouteEntry | Adds a custom route to a VBR route table |
| ModifyRouteEntry | Modifies the name and description of a custom route |
| DescribeRouteEntryList | Queries routes in a route table; use this to retrieve the next hop ID (NextHopId) before deleting a route |
| DeleteRouteEntry | Deletes a custom route from a VBR route table |