Reverting to the default advertisement

If you no longer need to advertise certain subnets or custom IP ranges, you can revert back to the default behavior.

By default, the Cloud Router advertises all available subnets, including new ones. For BGP sessions, the default behavior is to inherit the Cloud Router's behavior.

Revert advertisements on a Cloud Router

To revert advertisements on a Cloud Router to the default behavior, follow these steps.

Console

  1. In the Google Cloud Console, go to the Cloud Routers page.

    Go to Cloud Routers

  2. Select the Cloud Router to update.

  3. On the Router details page, click Edit.

  4. In the Advertised routes section, for Routes, select Advertise all subnets visible to the Cloud Router (Default).

  5. Click Save to revert to the default advertisement.

gcloud

Run the update command. Use the --advertisement-mode flag to change the advertisement mode to default, as shown in the following example:

gcloud compute routers update my-router \
    --advertisement-mode default

API

Use the routers.patch method to set bgp.advertiseMode to DEFAULT and clear the custom advertisement configuration:

PATCH https://compute.googleapis.com/compute/v1/projects/PROJECT_ID/regions/REGION/routers/ROUTER_NAME
{
  "bgp": {
    "advertiseMode": "DEFAULT",
    "advertisedGroups": [],
    "advertisedIpRanges": []
  }
}

Replace the following:

  • PROJECT_ID: the project that contains the Cloud Router
  • REGION: the region where the Cloud Router is located
  • ROUTER_NAME: the name of the Cloud Router

Revert advertisements on a BGP session

To revert advertisements on a BGP session to the default behavior, follow these steps.

Console

  1. In the Google Cloud Console, go to the Cloud Routers page.

    Go to Cloud Routers

  2. Select the Cloud Router that contains the BGP session to update.

  3. On the Router details page, select the BGP session to update.

  4. On the BGP session details page, click Edit.

  5. For Routes, select Advertise all subnets visible to the Cloud Router (Default).

  6. Click Save to revert to the default advertisement.

gcloud

Run the update-bgp-peer command. Use the --advertisement-mode flag to change the advertisement mode to default, as shown in the following example:

gcloud compute routers update-bgp-peer my-router \
    --peer-name my-bgp-session \
    --advertisement-mode default

API

For one or more BGP sessions, use the routers.patch method to update the bgpPeers[] field.

The bgpPeers[] field accepts an array of BGP peers. When you PATCH this field, you overwrite the existing array of BGP peers with the new array included in your request.

  1. Send a GET request to get the current array of BGP peers for the router. For details, see Viewing BGP session configuration.

  2. Send a PATCH request with a new array of BGP peers. For each BGP peer that you want to revert to the default advertisement, do the following:

    • Set advertisedMode to DEFAULT
    • Set advertisedGroup[] and advertisedIpRanges[] to []
    PATCH https://compute.googleapis.com/compute/v1/projects/PROJECT_ID/regions/REGION/routers/ROUTER_NAME
    {
      "bgpPeers": [
        BGP_PEERS
      ]
    }
    

    Replace the following:

    • PROJECT_ID: the project that contains the Cloud Router
    • REGION: the region where the Cloud Router is located
    • ROUTER_NAME: the name of the Cloud Router
    • BGP_PEERS: the contents of the new array of BGP peers

    The following example reverts two BGP sessions to the default advertisement:

        {
          "name": "peer-1",
          "interfaceName": "if-peer-1",
          "ipAddress": "169.254.10.1",
          "peerIpAddress": "169.254.10.2",
          "peerAsn": 64512,
          "advertisedRoutePriority": 100,
          "advertiseMode": "DEFAULT",
          "advertisedGroups": [],
          "advertisedIpRanges": []
        },
        {
          "name": "peer-2",
          "interfaceName": "if-peer-2",
          "ipAddress": "169.254.20.1",
          "peerIpAddress": "169.254.20.2",
          "peerAsn": 64513,
          "advertisedRoutePriority": 100,
          "advertiseMode": "DEFAULT",
          "advertisedGroups": [],
          "advertisedIpRanges": []
        }
    

What's next

  • To view the configuration of a Cloud Router, its BGP sessions, and the routes that Cloud Router is advertising, see Viewing Cloud Router details.

  • To troubleshoot custom route advertisement issues, see Troubleshooting.