Re-routing secondary subnets

You can re-route the secondary subnets that are assigned to your account on the Subnets page. For instance, you can:

Route an unrouted secondary subnet as a static secondary or portable secondary when needed
Re-route a portable secondary subnet as a static secondary subnet
Re-route a portable secondary subnet to another VLAN in the same data center
Re-route a static secondary subnet as a portable secondary subnet
Re-route a static secondary subnet to another IP address within the same VLAN
Unroute a static or portable secondary subnet without canceling it

Re-routing secondary subnets has no effect on billing. Unrouted secondary subnets remain billed and assigned to your account.

Secondary subnets in the unrouted state may be subject to automatic reclaim. Refer to the FAQs for more details on this policy.

Limitations when re-routing secondary subnets

The following limitations exist when re-routing your secondary subnets:

Scoped to a single data center

Secondary subnets are scoped to a single data center. If you order a secondary subnet in dal10 and wish to re-route it, your available routing endpoints will consist of dal10 IP addresses for static secondary routing and dal10 VLANs for portable secondary routing. If you are interested in subnets that are not scoped to a single data center, read more about global IP addresses.

Minimum size requirements for IPv4

Portable secondary subnets have a minimum size requirement of 8 addresses, or /29. Any static secondary subnets on your account that are /30 or smaller can be unrouted, but cannot be re-routed as portable secondary subnets. Any unrouted secondary subnets on your account that are /30 or smaller can be routed as static secondary subnets, but cannot be routed as portable secondary subnets. Any secondary subnets on your account that are /29 or larger can be routed as both static and portable secondary subnets.

Losing dependent routes

Re-routing portable secondary subnets with dependent routes causes those dependent routes to be lost. For example, if you have a static secondary subnet routed to a portable secondary subnet on your account and re-route the portable secondary subnet, the static secondary subnet will be unrouted as part of the portable secondary subnet re-route. Dependent routes that might be lost as a result of portable secondary subnet re-routing are displayed on the re-route confirmation page before any changes are made.

Re-routing secondary subnets using the UI

You can route and unroute secondary subnets assigned to your account using the UI. To do so, take the following steps:

From your browser, open the IBM Cloud console and log in to your account.
From the console, click the Menu icon and select Classic Infrastructure.
Select Network > IP Management > Subnets.
Click the overflow menu for the subnet you want to re-route and select Change route.
Select a Routing option.
Select a routing endpoint.
- For Unrouted secondary subnets, no routing endpoint is needed.
- For Static secondary subnets, a table of subnets is shown. Expand the subnet row(s) to see a list of IP addresses that are available to route your subnet to.
- For Portable secondary subnets, a table of VLANs is shown. Select the VLAN you want to route your subnet to.
Click Change route. A confirmation window will appear.
Review the route change details and click Confirm to proceed with the route change.

Re-routing secondary subnets using the API

You can route and unroute secondary subnets assigned to your account using the API.

Routing secondary subnets using the API

For more information on routing secondary subnets using the API, see route

Unrouting secondary subnets using the API

For more information on unrouting secondary subnets using the API, see clearRoute