thanks for your reply 
yes  I need public IP address  (external) directly in my instance but with router . I need a router because it adds many features including High Availability 
If I don't use a router  how can I have HA on my network ?


On Wed, Jul 27, 2022 at 1:58 PM Slawek Kaplonski <skaplons@redhat.com> wrote:
Hi,

Dnia środa, 27 lipca 2022 09:55:12 CEST Parsa Aminian pisze:
> hello
> is it possible to assign valid ip to openstack router directly without nat
> ? as I know openstack need invalid fix ip when using router and valid ip
> should be added as float ip .
>

I don't understand what do You mean by "invalid" and "valid" IP address. Can You explain it?
If You want to have public IP address  (external) directly in Your instnance, You can plug Your instance directly into the provider network, without using neutron router at all.

--
Slawek Kaplonski
Principal Software Engineer
Red Hat