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Route synchronization

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Route synchronization automatically propagates routes from a transit router route table to connected network instances.

Limitations

  • Only Enterprise Edition transit routers support route synchronization.

  • A VPC connected to multiple Enterprise Edition transit routers supports route synchronization on only one connection.

  • A VPC connected to a Basic Edition transit router cannot use route synchronization on an Enterprise Edition transit router connection.

  • If an IPsec-VPN connection is bound to a VPN Gateway that has automatic BGP route propagation enabled, route synchronization cannot be enabled for the associated VPC.

  • Synchronized routes cannot be deleted from the network instance.

  • Synchronized routes consume the custom route entry quota of the VPC's route tables.

    Each VPC route table supports up to 200 custom route entries by default. Request a quota increase on the VPC quota management page or in Quota Center.

  • Resource limits:

    Resource

    Default limit

    Adjustable

    VPCs with route synchronization enabled per Enterprise Edition transit router

    50

    Cannot be adjusted

How it works

  • Basic Edition transit routers automatically propagate routes from the default route table to connected network instances.

  • Enterprise Edition transit routers do not propagate routes by default. Enable route synchronization on each connection to start propagation.

    Note

    When you create a VPC connection, you can select Auto-add transit router routes to all VPC route tables in the Advanced Settings section. This adds three route entries (10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16) to all VPC route tables, directing IPv4 traffic to the transit router. If these routes suffice, route synchronization is unnecessary.

    Behavior by network instance type:

    • VPC instance

      Routes from the transit router route table associated with the VPC connection are synchronized to all VPC route tables.

    • ECR instance

      Routes from the transit router route table associated with the ECR connection are synchronized to the ECR route table.

      Important

      If you configure a route prefix for the transit router in the Express Connect console, only that prefix is propagated to the ECR instance, not the transit router's route table routes. Create and manage an ECR.

    • IPsec-VPN connection

      Note

      Route synchronization applies only to IPsec-VPN connections that use BGP dynamic routing.

      Routes from the transit router route table associated with the VPN connection are synchronized to the IPsec-VPN connection's BGP route table.

    • VBR instance

      Routes from the transit router route table associated with the VBR connection are synchronized to the VBR route table.

    • inter-region connection

      Routes from the local transit router route table associated with the inter-region connection are synchronized to the peer transit router.

Enable route synchronization

Enable route synchronization when creating a connection or on an existing connection.

Enable route synchronization during connection creation

  • ECR instance

    When you create an ECR connection, Automatically Advertise Routes to ECR is enabled by default in the Advanced Settings section. This setting enables route synchronization for the ECR instance and cannot be disabled.

  • IPsec-VPN connection

    When you create a VPN connection, select Automatically Advertise Routes to VPN in the Advanced Settings section to enable route synchronization.

  • VBR instance

    When you create a VBR connection, select Propagate Routes to VBR in the Advanced Settings section to enable route synchronization.

  • inter-region connection

    When you create an inter-region connection, select Automatically Advertise Routes to Peer Region in the Advanced Settings section to enable route synchronization.

Note

VPC route synchronization requires an Enterprise Edition transit router connection.

Enable route synchronization for an existing connection

The connection must be associated with an Enterprise Edition transit router route table.

Two methods are available for VBR and IPsec-VPN connections. VPC supports only Method 1. Inter-region connections support only Method 2.

Method 1

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

  2. On the CEN Instance page, find the CEN instance and click its ID.

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

  4. On the Intra-Region Connections tab, find the target network instance connection, and enable the switch in the Route Synchronization column.

    After route synchronization is enabled, routes are automatically synchronized to the network instance. Click Route Synchronization in the Details column to view synchronization status on the Network Instance Route Table tab.

Method 2

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

  2. On the CEN Instance page, find the CEN instance and click its ID.

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

  4. On the transit router details page, find the connection and click its ID.

    • To find a VBR or IPsec-VPN connection, click the Intra-Region Connections tab.

    • To find an inter-region connection, click the Inter-Region Connections tab.

  5. In the Attachment Details panel, go to the Basic Information section and click Automatic Route Advertisement next to Enable.

  6. In the Enable Automatic Route Advertisement dialog box, click OK.

Disable route synchronization

Warning

  • Disabling route synchronization withdraws all synchronized routes from the network instance. Ensure redundant routes are in place before proceeding.

  • The 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 routes added during VPC connection creation are not withdrawn.

Two methods are available for VBR and IPsec-VPN connections. VPC supports only Method 1. Inter-region connections support only Method 2.

Method 1

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

  2. On the CEN Instance page, find the CEN instance and click its ID.

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

  4. On the Intra-Region Connections tab, find the target network instance connection, and disable the switch in the Route Synchronization column.

Method 2

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

  2. On the CEN Instance page, find the CEN instance and click its ID.

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

  4. On the transit router details page, find the connection and click its ID.

    • To find a VBR or IPsec-VPN connection, click the Intra-Region Connections tab.

    • To find an inter-region connection, click the Inter-Region Connections tab.

  5. In the Attachment Details panel, go to the Basic Information section and click Automatic Route Advertisement next to Disabled.

  6. In the Disable Automatic Route Advertisement dialog box, click OK.

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