A Public IP, also called a Floating IP, is an address the internet can reach. Servers sit on a private network by default and have no public address until you attach one. You manage these under Networking, then Public IPs.
The address is "floating" because it belongs to your account, not to a particular server. You can move it from one server to another, which is handy when you rebuild a server but want to keep the same address.
Attach a public IP
The quickest way is from the server itself:
- Open Cloud Servers, click your server, and choose Associate Floating IP.
- Pick a spare address or click Allocate IP to get a new one, then associate it.
You can also allocate and manage addresses directly under Public IPs.
Remember that a public address alone does not let traffic in; you still need to open the ports you want to use. A Floating IP costs a small amount while it is allocated to you, attached or not, so release any you are not using. See Delete things to stop charges.