Modifying VLAN attachments

This document describes how to modify VLAN attachments for Dedicated Interconnect.

The following table lists properties associated with VLAN attachments and describes how to modify the properties.

Property How to modify




For details, see the next section Modifying description, capacity, and MTU.

Modifications are immediate and don't disrupt traffic.

Whether a VLAN attachment is enabled or disabled To disable or re-enable a VLAN attachment, see Disabling VLAN attachments.


BGP IP addresses (Cloud Router IP address, on-premises router IP address)

You can't modify these properties for existing attachments. Instead, you must recreate the VLAN attachment.

To create VLAN attachments for Dedicated Interconnect, see Creating VLAN attachments.

The peer ASN is not a property of the VLAN attachment—it is part of the BGP configuration of the Cloud Router. To modify the peer ASN, update the Cloud Router's BGP session for the VLAN attachment.

For more information, see the following resources:

Modifying description, capacity, and MTU

The section provides instructions for updating the description, capacity, and maximum transmission unit (MTU) of a VLAN attachment.

To make use of the 1500-byte MTU, the VPC network using the attachment must have an MTU set to 1500. In addition, the on-premises VMs and routers must have an MTU set to1500. If your network has the default MTU of 1460, leave the field at 1440.


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

    Go to VLAN attachments

  2. Select the VLAN attachment to modify.

  3. On the attachment's detail page, click Edit.

  4. Modify your VLAN attachment:

    • Description: Information about the VLAN attachment.
    • Capacity: The maximum bandwidth of the attachment.
    • Maximum transmission unit (MTU): The MTU of the attachment.
  5. Click Save.


Modify an interconnectAttachment by specifying the name of the existing VLAN attachment and the attributes to modify:

gcloud compute interconnects attachments dedicated update NAME \
    --region=REGION \
    --description=DESCRIPTION \
    --bandwidth=BANDWIDTH \
    --mtu MTU

Replace the following:

  • NAME: the name of the existing VLAN attachment
  • REGION: the region of the attachment
  • DESCRIPTION: a description of the attachment
  • BANDWIDTH: the provisioned capacity of the attachment
  • MTU: the MTU of the attachment

For more information, see the gcloud compute interconnects attachments dedicated update reference.

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