Modify VLAN attachments

This document describes how to modify Partner Interconnect VLAN attachments and their Border Gateway Protocol (BGP) sessions.

The following table lists VLAN attachment and BGP session properties. It also provides information about how to modify them.

Property How to modify
Capacity Work with your service provider as described in the Modify capacity section in this document.
Description and MTU

See the Modify the description and MTU section in this document.

Modifications are immediate and in rare cases can cause traffic disruption. If traffic is disrupted, the disruption lasts less than a minute.
Stack type Not modifiable. Partner Interconnect supports only IPv4 traffic.
Whether a VLAN attachment is enabled or disabled To disable or re-enable a VLAN attachment, see Disable VLAN attachments.

VLAN ID

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 Partner Interconnect, see Create VLAN attachments.
Custom learned routes Follow the steps in Update an existing session to use custom learned routes.
MD5 authentication If you have a Layer 2 connection, follow the steps in Add authentication to an existing session. If you have a Layer 3 connection, contact your service provider for instructions.

The peer ASN is not a property of the VLAN attachment—it is part of the BGP configuration of the Cloud Router. If you have a Layer 2 connection and you want to modify the peer ASN, update the Cloud Router's BGP session for the VLAN attachment.

For more information, see the following resources:

Modify capacity

For an existing VLAN attachment, Google Cloud supports increasing or decreasing the attachment's capacity as your capacity demands rise or fall. Because capacity changes can affect your service provider's network, you must work with them to change your attachment's capacity. Changes in capacity, in rare cases, can cause traffic disruption. If traffic is disrupted, the disruption lasts less than a minute.

After the service provider has updated your attachment, your service provider works with Google to update the attachment's capacity in your Google Cloud project. At that time, Google updates the charges for the attachment based on the new capacity.

If you modify the capacity of an encrypted VLAN attachment, you might need to add HA VPN tunnels to accommodate increased traffic. For more information, see Configure HA VPN over Cloud Interconnect.

For a list of all the service providers, see Supported service providers.

Modify the description and MTU

This section provides instructions for updating the description and MTU of a VLAN attachment. In rare cases, changing the attributes of a VLAN attachment can cause traffic disruption. If traffic is disrupted, the disruption lasts less than a minute.

To make use of the 1460 or 1500-byte MTU, the VPC network that uses the attachment must have the same MTU value. In addition, the on-premises VMs and routers must have the same MTU value. If your network has the default MTU of 1460, then select an MTU of 1460 for your VLAN attachment.

You cannot modify the MTU (1440) of an encrypted VLAN attachment that is used in an HA VPN over Cloud Interconnect deployment.

Console

  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 the Description of your VLAN attachment, and then click Save.

  5. Optional: Update the maximum transmission unit (MTU) of the attachment.

gcloud

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

gcloud compute interconnects attachments partner update NAME \
    --region=REGION \
    --description=DESCRIPTION \
    --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
  • MTU: the MTU of the attachment

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

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