Duplicate a VLAN attachment for redundancy

If you have an existing VLAN attachment for a Partner Interconnect connection, you can create a second one to build redundancy. We recommend redundancy so that if one VLAN attachment fails, the other one can continue to serve traffic.

To create a redundant VLAN attachment, it must connect to Google Cloud in the same metropolitan area (city) as the existing VLAN attachment but in a different edge availability domain (metro availability zone).


  1. In the Google Cloud console, go to the Cloud Interconnect VLAN attachments tab.

    Go to VLAN attachments

  2. Click Add VLAN attachment.

  3. Select Partner Interconnect, and then click Continue.

  4. Click I already have a service provider.

  5. Under Redundancy, select Add a redundant VLAN to an existing VLAN.

  6. In the Select VLAN attachment field, select the attachment that you want to build redundancy for. The new redundant attachment uses the same VPC network and region as the existing one.

  7. Specify the details of your VLAN attachments:

    • Cloud Router: Choose the Cloud Router that's associated with the existing attachment. The Cloud Router must have an ASN of 16550. If you don't have an existing Cloud Router that you can use, create one with an ASN of 16550.
    • VLAN attachment name: A name for the attachment. This name is displayed in the Google Cloud console and is used by the Google Cloud CLI to reference the attachment, such as my-attachment.
  8. Click Create to create the attachments, which takes a few minutes.

  9. After creation is complete, copy the pairing keys. You need to share these keys with your service provider when you request a connection with them.

  10. Click OK to view a list of your VLAN attachments.


Use the existing Cloud Router in the network and region that contains the existing VLAN attachment. The Cloud Router must have an ASN of 16550. If you don't have an existing Cloud Router that you can use, create one before you create a VLAN attachment. When you create the Cloud Router, use 16550 for the BGP ASN.

  1. Describe your existing VLAN attachment to view its details. Record its edge availability domain (metro availability zone).

  2. Create a VLAN attachment of type PARTNER, specifying the name of your duplicate Cloud Router and a different edge availability domain from the existing VLAN attachment.

    The following example creates a VLAN attachment in edge availability domain availability-domain-2 and is associated with the Cloud Router my-router, which is in the region us-central1:

    gcloud compute interconnects attachments partner create my-second-attachment \
       --region us-central1 \
       --router my-router \
       --edge-availability-domain availability-domain-2
  3. Describe the attachment to retrieve its pairing key; you need to share this key with your service provider when you request a connection with them:

    gcloud compute interconnects attachments describe my-second-attachment \
       --region us-central1


    adminEnabled: false
    edgeAvailabilityDomain: AVAILABILITY_DOMAIN_2
    creationTimestamp: '2017-12-01T08:29:09.886-08:00'
    id: '7976913826166357434'
    kind: compute#interconnectAttachment
    labelFingerprint: 42WmSpB8rSM=
    name: my-second-attachment
    pairingKey: 7e51371e-72a3-40b5-b844-2e3efefaee59/us-central1/2
    region: https://www.googleapis.com/compute/v1/projects/customer-project/regions/us-central1
    router: https://www.googleapis.com/compute/v1/projects/customer-project/regions/us-central1/routers/my-router
    selfLink: https://www.googleapis.com/compute/v1/projects/customer-project/regions/us-central1/interconnectAttachments/my-second-attachment
    type: PARTNER

    The pairingKey field contains the pairing key that you need to share with your service provider. Treat the pairing key as sensitive information until your VLAN attachment is configured.

    The state of the VLAN attachment is PENDING_PARTNER until you request a connection with your service provider and they complete its configuration. After the configuration is complete, the state of the attachment changes to ACTIVE.

What's next?