Create IPv4 sub-prefixes and IPv4 addresses

This page describes how to divide your IPv4 public delegated prefix and create BYOIP addresses to use with Google Cloud resources. You can create IPv4 BYOIP addresses from a public delegated prefix or sub-prefix.

If you want to divide an IPv6 public delegated prefix, see Create IPv6 sub-prefixes.

Before you begin

1. Create an IPv4 public advertised prefix.
2. Create an IPv4 public delegated prefix.

Roles

To get the permissions that you need to complete the tasks in this guide, ask your administrator to grant you the Compute Public IP Admin (roles/compute.publicIpAdmin) IAM role on your project. For more information about granting roles, see Manage access to projects, folders, and organizations.

You might also be able to get the required permissions through custom roles or other predefined roles.

Create sub-prefixes

You can divide a public delegated prefix into smaller IP address ranges by creating a sub-prefix. A sub-prefix is a public delegated prefix that has a public delegated prefix parent.

A sub-prefix name can't be changed without deleting and recreating the resource. For this reason, we recommend that you create generic names that won't need to change—for example, sub-203-0-113-0-28, where sub denotes the resource type and 203-0-113-0-28 denotes the specific prefix and prefix length.

A public delegated prefix can be sub-delegated up to three times from a public advertised prefix. For example, if you have a public advertised prefix with IP address range 203.0.113.0/24, you can do the following:

• Create a public delegated prefix with IP address range 203.0.113.0/25 from the public advertised prefix.
• Create a sub-prefix with IP address range 203.0.113.0/26 that has the previous public delegated prefix as its parent.
• Create a sub-prefix with IP address range 203.0.113.0/27 that has the previous sub-prefix as its parent.

At this point, you cannot create further sub-prefixes that have the 203.0.113.0/27 sub-prefix as a parent.

gcloud compute public-delegated-prefixes \
    delegated-sub-prefixes \
    create SUB_PREFIX_NAME \
    --range=SUB_PREFIX_RANGE \
    --public-delegated-prefix=PDP_NAME \
    --public-delegated-prefix-region=PDP_REGION \
    --delegatee-project=PROJECT_ID

List prefixes

You can list all public advertised prefixes and public delegated prefixes (including sub-prefixes) in a project.

gcloud compute public-delegated-prefixes list

Create IP addresses

When you create addresses from a public delegated prefix or sub-prefix, you cannot further sub-divide that prefix.

The IP addresses that you create from a public delegated prefix or sub-prefix are static external IP addresses and can be regional or global. All IP addresses in the public delegated prefix or sub-prefix are made available; there is no reserved network address or broadcast address. For example, if you create IP addresses from a /28 public delegated prefix or sub-prefix, 16 IP address resources are created.

You can list all static external IP addresses. This list includes IP addresses that you have brought to Google Cloud and IP addresses that are provided by Google.

BYOIP addresses are created with names in a consistent format. For example, 203.0.113.144 is assigned the name address-203-0-113-144.

gcloud compute public-delegated-prefixes \
    delegated-sub-prefixes \
    create ADDRESSES_NAME \
    --create-addresses \
    --public-delegated-prefix=PDP_NAME \
    --public-delegated-prefix-region=PDP_REGION

What's next

• Manage BGP announcement (v2)