Public IP Blocks

An IP block is a range of public addresses, written in CIDR notation such as /29. The console calls these blocks Prefixes. Each block belongs to one Virtual Network in one datacenter.

How sharing works

A public Virtual Network connects your servers to the block's gateway. Attach several servers in your organization to that network, then assign each server different addresses from its blocks. A server can have more than one address. The servers must be in the block's datacenter.

For example, two servers on a network named Web could share 198.73.57.0/29:

This /29 contains eight addresses, with five available to servers after the network, broadcast, and gateway addresses. Use the block and gateway assigned to you in the console.

Sharing a block means distributing its addresses. An address can be assigned to only one server at a time; this does not set up automatic failover.

A server ordered with public IP space starts with its own Internet Access network and bundled blocks. For a shared pool, order a separate block: it has its own subscription. A bundled block is tied to the original server's subscription.

Add a block and assign addresses

1. Open Virtual Networks in the cloud console. Use an existing public network, or select Create Virtual Network, enter a name, choose Public, and create it.
2. Open the network's Prefixes page and select Request prefix. Choose an available IP block size, datacenter, and billing cycle. Select the intended Virtual Network in the order configuration, complete checkout, and pay any required invoice.
3. Open the network and select Attach server. Choose a server, its interface, and Native or Tagged mode. Wait for Attached and repeat for each server. See Virtual Networks for attachment details.
4. Under Prefixes, select Manage beside the block, then Assign address. Choose a free address, the server, and its interface. Repeat with a different address for each server.

Attaching a server makes the network available to it; assigning an address records which server uses that address. Both are needed. A Reserved address is held out of the free pool: release its reservation before assigning it.

Configure the operating system

Public addresses use static configuration, not DHCP. Standard deployment configures the assigned addresses; addresses added afterward need to be configured inside the OS.

Copy the address, subnet mask or prefix length, and gateway from the block's details. With a Native attachment, configure the physical interface or bond. With a Tagged attachment, create a VLAN interface using the network's VLAN ID and configure the address there. Keep a single intended default route per address family when adding extra addresses.

Save persistent settings with Netplan or NetworkManager. Keep the remote console open while changing connectivity. Custom iPXE makes all production networks tagged until you return to local-disk boot.

Use Reverse DNS (rDNS) to set and verify the hostname for an IPv4 address. IPv6 uses the same block and network model, but new IPv6 assignments currently require the API; the console's assignment control is disabled for IPv6. IPv6 reverse DNS is not currently supported.

Move or release addresses

To move an address, remove it from the old server's OS, Unassign it in the block's address list, then assign it to another server attached to the same network and configure that OS. Unassigning also removes its reverse DNS record; recreate it if needed.

Unassigning keeps the server's network attachment and does not cancel the block or stop its billing. Before releasing a separately ordered block, remove all its server address assignments. See Billing for usage and prepaid terms, or Manage IP addresses through the API for automation.