How Add/Remove Floating IP’s to your VM?

To make your VM accessible from the Internet you probably use or want to use Floating IP’s. Floating IP’s in Openstack are public IP adressess assigned to your Virtual Machine. The name is a bit misleading, because those adresses are permanent, they are not changing (as the name „floating” may suggest) once assigned to the VM. Assigning Floating IP can allow you (assuming you have Security Groups set properly) to host services like SSH, HTTP or other over the Internet.

 

How to assign Floating IP to your VM:

In Instances tab in Horizon, click the dropdown menu next to your VM and choose „Associate Floating IP”

 

You will be shown a window like this one:


You may choose an address from dropdown menu, but if its empty, you need to allocate an adress first. Click "+" icon on the right.


Click "Allocate IP"


Notice: the IP Adress should be associated with local adress from "192.168.x.x" subnet. If you have "10.x.x.x" address change it to "192.168.x.x" address.

Click "Associate".

You now have public IP assigned to your instance and visible in Instances menu:
 


You can now connect to your Virtual Machine trough SSH or RDP from the Internet.

Notice: The VM's communicate between themselve trough internal network "192.168.x.x" so if you are connecting from one Virtual Machine to another you should use private adresses.

 

How to dissasociate Floating IP:

If you no longer need public IP address you may dissasociate it from your VM. Click "Dissasociate Floating IP" from the dropdown menu:

 

How to release Floating IP (return it to the pool)

Floating IP’s as any other Openstack resources have their cost when kept reserved and not used.

If you dont want to keep your Floating IP’s reserved for your project you may release them to the Openstack pool for other users which will also reduce your project costs.

Go to Access & Security → Floating Ips

For the adress that is not in use the "Release Floating IP" option will be avaliable. Click it to release the IP address.