Migrate from VBR-to-VPC connections to ECR connections
Express Connect Router (ECR) supports automatic route distribution and learning, and provides lower forwarding latency than virtual border router (VBR)-to-VPC peering connections. This topic walks you through migrating from Express Connect peering connections based on VBRs to ECR connections between your data center and virtual private clouds (VPCs).
Prerequisites
Before you begin, ensure that you have:
An ECR. For more information, see Create and manage ECRs
Feature comparison
| Feature | VBR-to-VPC | ECR |
|---|---|---|
| Static routing | Supported | Not supported |
| Dynamic routing | Not supported | Supported |
| Multi-access points | Not supported | Supported |
| Bidirectional Forwarding Detection (BFD) | Not supported | Supported |
| Nearby forwarding with low latency | Not supported | Supported |
| Pay-as-you-go billing | Not supported | Supported |
Migration scenarios
Review your current topology and identify your scenario before starting the migration.
Scenario 1: Active/standby VBR-to-VPC connection
In this scenario, VBR 1 and VBR 2 both connect to the same VPC. VBR 1 has a route weight of 100 (active) and VBR 2 has a weight of 0 (standby). Both VBRs use Border Gateway Protocol (BGP) to connect with the data center.
Before migrating, confirm that the following BGP configuration is in place:
The data center and VBRs are configured as BGP peers and are advertising routes. For more information, see Configure and manage BGP. The autonomous system number (ASN) of Alibaba Cloud is 45104. The data center can use 2-byte or 4-byte ASNs.
BGP routing is configured in the data center and routes are advertised to Alibaba Cloud. The AS path attribute determines route weights for the active/standby setup. The AS path of the active route must be longer than that of the standby route. A shorter AS path means higher priority. Contact your service provider for the commands used to configure BGP routing.
Scenario 2: Active/active VBR-to-VPC connection
In this scenario, VBR 1 and VBR 2 both connect to the same VPC with a route weight of 100 each. Both VBRs use BGP to connect with the data center.
Before migrating, confirm that the following BGP configuration is in place:
The data center and VBRs are configured as BGP peers and are advertising routes. For more information, see Configure and manage BGP. The ASN of Alibaba Cloud is 45104. The data center can use 2-byte or 4-byte ASNs.
BGP routing is configured in the data center and routes are advertised to Alibaba Cloud. The AS path attribute determines route weights for the active/active setup. The AS path lengths of both routes must be equal. Equal path length means equal priority. Contact your service provider for the commands used to configure BGP routing.
Migration process
The migration follows four phases: preparation, ECR onboarding, route cutover, and (if needed) multi-VPC route prefix configuration.
Phase 1: Preparation
If health checks are configured for your VBRs, delete them before proceeding.
Log on to the Express Connect console.
Delete the health check settings for your VBRs. For more information, see Configure and manage health checks.
Phase 2: Add VBRs and VPC to the ECR
Log on to the Express Connect console.
In the left-side navigation pane, click Express Connect Router (ECR). On the page that appears, click the name of the ECR.
On the ECR details page, add the VBRs to migrate on the VBR tab and the target VPC on the VPC tab. For more information, see the Add a VBR and Associate a VPC sections of the "Create and manage ECRs" topic.
After adding the VBRs and VPC to the ECR, both static and dynamic routes between them are established automatically.
Phase 3: Delete static routes
Delete the static routes between the VPC and VBRs. For more information, see the Add and delete routes section of the "Create and manage a route table" topic and the Delete a custom route section of the "Add and manage routes" topic.
After you add the VBRs and VPC to the ECR, the VBRs and VPC have static and dynamic routes that point to each other.
Phase 4: Configure route prefixes (conditional)
If your data center needs to access services in multiple VPCs, configure route prefixes to control which IP ranges are advertised between each VPC and your data center.
Configure the route prefixes for your ECR. For more information, see the Update route prefixes section of the "Create and manage ECRs" topic.