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VLAN spanning

VLAN spanning

VLAN spanning enables all devices on an account to communicate with each other by using the private network. This feature is only for older accounts and is mutually exclusive with VRF feature on an account.

Only enable VLAN spanning if you can't or don't want to enable Virtual Routing and Forwarding (VRF). For more information, see Network segmentation.

Understanding VLAN spanning

In IBM Cloud®, VLAN spanning can be used for many different purposes and has an impact on device communication. To learn more about the basics of VLAN spanning before you get started, review the following information.

How VLAN spanning works

By enabling VLAN spanning, all of your routed traffic can travel between all private subnets, across all private VLANs on your account. VLAN spanning serves business needs that require the global communication of your routed traffic. For example, enable VLAN spanning if devices that reside on more than one private subnet need to communicate, whether on the same or different VLANs.

When spanning is enabled, it affects the entire account. You cannot exempt any subnets, VLANs, or devices from VLAN spanning. If you currently rely solely on private subnets to separate servers into roles or tiers, enabling VLAN spanning removes that separation.

Default values

By default, VLAN spanning is disabled. Devices on two different private subnets, whether on the same or different VLANs, can't send IP traffic to one another.

Managing VLAN spanning

You can enable or disable VLAN spanning for your account.

This option will not appear for accounts that are incompatible with VLAN Spanning.

To update your account setting, follow these steps:

  1. From your browser, open the IBM Cloud console and log in to your account.

  2. From the console, click the Navigation Menu icon Navigation Menu icon and select Classic Infrastructure.

  3. Select Network > IP Management > VLANs.

  4. Select the VLAN Spanning toggle button to enable or disable VLAN spanning as needed.

    Toggling VLAN Spanning within a short amount of time might delay application.

The update request can take up to 15 minutes to process. A confirmation of the change appears on the page. You can update your VLAN spanning settings at any time by repeating these steps.