A Floating IP is a portable public IP address owned by your organization. You can assign it to one machine, then move it to another at any time without changing the address. Manage them on the Floating IPs page in my.cubepath.com.

What it's for

Because the IP belongs to your organization and not to a single machine, it keeps the same address across rebuilds and migrations. That makes it the right tool for:

  • Stable DNS records, so a rebuild doesn't mean editing DNS and waiting out a TTL.
  • Failover, moving the address to a standby machine in seconds.
  • Migrations, cutting traffic over to a new server without touching anything that points at the old one.
  • Whitelisted addresses, where a partner has registered your IP and changing it means a support ticket on their side.

Acquire an IP

Click Acquire IP, choose the Type (IPv4) and the Location, then confirm. The new address appears under the Single IPs tab.

Larger allocations are grouped as Subnets, where you can expand a range to see and manage every individual IP it contains.

Assign and unassign

The Assigned To field shows the VM or dedicated server an IP is currently attached to, or Unassigned if it's free. Move or detach an IP to point it at a different machine.

Configure the IP inside the guest OS

Most of the time the machine picks the address up on reboot and there's nothing to do. When it doesn't — a static-networking image, or an extra address on a machine that already has one — add it by hand.

First check what the OS actually sees:

ip -br addr

Then add the address persistently, using whatever your distribution uses:

  • Ubuntu (netplan) — add the address to the interface block in /etc/netplan/*.yaml, then test with sudo netplan try. It auto-reverts after 120 seconds if you lose SSH, which turns a mistake into a two-minute wait instead of a console session.
  • Debian (interfaces) — add the address to /etc/network/interfaces, then sudo systemctl restart networking.
  • RHEL / CentOS / Rocky — use nmcli, or add it to the interface's configuration under /etc/sysconfig/network-scripts/ and restart networking.

Additional addresses are configured with a /32 mask (IPv4) or /128 (IPv6): they're routed to your machine individually, not as part of a local subnet. The default gateway stays the one your primary address already uses — don't add a second one.

Verify with ip -br addr again, and from outside with a ping or a connection to a service bound to the new address.

Reverse DNS (rDNS)

For an assigned IP, use the edit control next to Reverse DNS to set its PTR record (for example mail.example.com). Leave it empty to remove the record.

This matters most for outbound mail: many receiving servers reject or spam-folder messages from an IP whose reverse lookup doesn't resolve, or doesn't match the sending hostname. It's also worth setting on a NAT Gateway's egress address, so a partner can tell which of your addresses is calling their API.

Release an IP

Use the delete action on a secondary IP to release it back. The address returns to the available pool and billing stops.

When you delete a machine, the confirmation dialog asks whether to keep floating IPs in your organization. Keeping them means they keep billing but stay yours; releasing them stops the charge but gives the addresses up.