Upgrade a Basic Edition transit router

Step 1: Schedule the upgrade

• Before you upgrade a Basic Edition transit router, Alibaba Cloud Support must provision transit resources. This takes up to 72 hours, so schedule the upgrade at least 72 hours in advance. For an emergency upgrade, contact your account manager.

• Network interruptions may occur during the upgrade. Migrate workloads, notify end users, and perform the upgrade during off-peak hours.

• The upgrade takes 10 to 20 minutes. Reserve a 1-hour maintenance window.

1. Log on to the CEN console.

2. On the CEN Instance page, click the ID of the CEN instance that you want to manage.

3. On the details page of the CEN instance, you can go to the upgrade page in either of the following ways:

   • On the Basic Settings > Transit Router tab, find the target Basic Edition Transit Router instance and click Upgrade in the Edition column.

   • On the Basic Settings > Transit Router tab, find the target Basic Edition Transit Router instance and click the instance ID. On the details page of the transit router, click the Basic Settings tab and click Upgrade next to Version.

4. In the Upgrade Transit Routers to Enterprise Edition dialog box, review the features and billing information of the Enterprise Edition Transit Router and click Upgrade.

5. On the Schedule Upgrade page, select the availability zones for the Enterprise Edition Transit Router and click Schedule Upgrade.

   An Enterprise Edition transit router can be deployed in one or more availability zones in a region. During the upgrade, the transit router creates an elastic network interface (ENI) in a vSwitch within each selected availability zone. The ENI serves as the communication interface between the VPC and the transit router.

   In regions that support multiple availability zones, such as China (Hangzhou), select at least two zones to ensure high availability.

   Note

   Select all available zones to reduce traffic detours and lower latency. Route selection for VPC connections.

   After you schedule the upgrade, Alibaba Cloud provisions the transit resources and approves your request within 72 hours. After approval, the status on the Schedule Upgrade page changes to Migrated. The Migrated status indicates that resources are provisioned. Complete the preparations in the following section before you start the upgrade.

Step 2: Make preparations

Complete the following preparations before you start the upgrade.

1. If the Basic Edition transit router is connected to VPCs, prepare vSwitch resources for each VPC.

   Ensure each VPC attached to the Basic Edition transit router has a vSwitch in each availability zone specified for the Enterprise Edition transit router. The Enterprise Edition transit router creates an ENI on the vSwitch of each availability zone as the communication interface between the VPC and the transit router. Each ENI consumes one IP address from the vSwitch. Make sure the vSwitch has sufficient IP addresses. Create a vSwitch.

   For example, to upgrade a Basic Edition transit router in China (Hangzhou) where the Basic Edition transit router is connected to VPC1 and VPC2, and you selected Availability Zone H and Availability Zone I in Step 1, both VPCs must have a vSwitch in each of those two zones.

   Note

   • If vSwitches already exist in the availability zones, do not use them. Create a dedicated vSwitch in each zone for the Enterprise Edition transit router. Follow these guidelines:

     • Use the smallest possible CIDR block, such as /28 (for example, 192.168.10.0/28).

     • If you use network ACLs, bind the new vSwitches to the same ACL with inbound and outbound rules that allow all traffic. Bind the vSwitches that host your workloads to a separate ACL to control traffic.

     • Bind the new vSwitches to the same VPC route table.

   • If the Basic Edition Transit Router is connected to a Virtual Border Router (VBR) instance, no action is required on the VBR instance.

2. Back up your route entries.

   Back up all route entries in your CEN instance before the upgrade so you can verify consistency afterward.

   1. Log on to the Cloud Enterprise Network (CEN) console.

   2. On the CEN Instance page, find the CEN instance that you want to manage and click its ID.

   3. On the Basic Settings > Transit Router tab, find the target Basic Edition Transit Router instance and click its ID.

   4. On the details page of the transit router, click the Route Table tab.

   5. On the Route Table tab, click the icon to download the route entries for the current region. Save the route entry information to your local computer.

   6. Repeat the preceding steps to download and save the route entries for all regions in the CEN instance.

3. Prepare testing resources to verify network connectivity after the upgrade.

Step 3: Start the upgrade

After your request is approved and preparations are complete, start the upgrade.

1. Log on to the Cloud Enterprise Network (CEN) console.

2. On the CEN Instance page, click the ID of the CEN instance that you want to manage.

3. On the details page of the CEN instance, you can go to the upgrade page in either of the following ways:

   • On the Basic Settings > Transit Router tab, find the target Basic Edition Transit Router instance and click Upgrade in the Edition column.

   • On the Basic Settings > Transit Router tab, find the target Basic Edition Transit Router instance and click the instance ID. On the details page of the transit router, click the Basic Settings tab and click Upgrade next to Version.

4. In the Upgrade Transit Routers to Enterprise Edition dialog box, click Upgrade.

5. On the Schedule Upgrade page, click Next.

6. On the Specify vSwitch page, configure the parameters as described in the following table and click Next.

   Parameter	Description
   Apply for Zones	The system automatically populates this field with the availability zones that you selected on the Schedule Upgrade page.
   Delete Default Cloud Service	Select Delete Default Cloud Service.
   Notes on Creating Service-Linked Roles	During the upgrade, the system automatically creates a service-linked role named AliyunServiceRoleForCEN. This role grants the Enterprise Edition transit router permissions to create ENIs in the vSwitches of the destination VPCs. AliyunServiceRoleForCEN.
   Select the vSwitch to which the VPC is connected.	Select a vSwitch for each VPC connection. The Enterprise Edition transit router creates an ENI in the specified vSwitch. If the selected vSwitch is associated with a network ACL, ensure its inbound and outbound rules allow all traffic to prevent connectivity issues.

7. On the Configure VPC Routes page, select Automatically Switch to Static Routes and click Next.

8. On the Confirm Settings and Price page, confirm the network instance information, review and agree to the billing terms, and then click Next.

9. In the Schedule Upgrade dialog box, specify a time for the upgrade or select Upgrade Now, and then click OK.

   • If you schedule an upgrade time, the system starts the upgrade automatically. Do not modify the Basic Edition transit router until the upgrade is complete.

   • If you select Upgrade Now, the upgrade starts immediately. Wait for it to complete.

Step 4: Verify the upgrade

After the upgrade, compare route entries and test network connectivity to verify success.

1. Compare route entries.

   View or download the route entries after the upgrade and compare them with the pre-upgrade entries.

   1. Log on to the Cloud Enterprise Network (CEN) console.

   2. On the CEN Instance page, find the CEN instance that you want to manage and click its ID.

   3. On the Basic Settings > Transit Router tab, find the target Enterprise Edition Transit Router instance and click its ID.

   4. On the details page of the transit router instance, click the Route Table tab.

   5. On the Route Entry tab, view the route entries in the current region.

      If you have many route entries, click the icon to download them.

2. Test network connectivity to ensure all services are running as expected.

FAQ

Can I downgrade to Basic Edition?

No. The upgrade to Enterprise Edition is irreversible.