I have a single system with a single network interface and 2 ip addresses. I would like to configure a provider network on neutron (on devstack). My idea is to have a several VMs but one of them with a provider IP that I can use to access the provider network.

My single interface has IP 20.20.20.15 and I have an extra IP 20.20.20.16 that I want to provide to one VM so it can access the provider network.

It seems that in order to use floating IP I would need to have available at least 3 IP addresses, what I do not have (not sure if this is true)

IP address 20.20.20.15 is my HOST ip address.