So Here is my senario,

I have a dedicated server hosted at Hetzner with a public ip 176.9.25.244 I also have a subnet 78.47.22.216/29

I want to create instances with floating ip's from the subnet and have my main machine which is running all in one packstack openstack on it to have the main 176.x.x.x ip.

When I installed openstack packstack allinone it created a br-ex interface which routes to 176.9.13.244 I added the subnet to my host machine so here is my ifconfig for my hostmachine

    [root@host1 ~]# ifconfig
br-ex: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 172.24.4.225  netmask 255.255.255.240  broadcast 0.0.0.0
        inet6 fe80::88da:beff:fe80:f644  prefixlen 64  scopeid 0x20<link>
        ether 8a:da:be:80:f6:44  txqueuelen 0  (Ethernet)
        RX packets 40  bytes 2736 (2.6 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 8  bytes 720 (720.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 176.9.13.244  netmask 255.255.255.255  broadcast 176.9.13.244
        inet6 fe80::a60:6eff:fe68:140a  prefixlen 64  scopeid 0x20<link>
        inet6 2a01:4f8:141:3ea::2  prefixlen 64  scopeid 0x0<global>
        ether 08:60:6e:68:14:0a  txqueuelen 1000  (Ethernet)
        RX packets 388451  bytes 565746616 (539.5 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 48434  bytes 10128875 (9.6 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

eth0:1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 78.47.37.218  netmask 255.255.255.248  broadcast 78.47.37.223
        ether 08:60:6e:68:14:0a  txqueuelen 1000  (Ethernet)

eth0:2: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 78.47.37.219  netmask 255.255.255.248  broadcast 78.47.37.223
        ether 08:60:6e:68:14:0a  txqueuelen 1000  (Ethernet)

eth0:3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 78.47.37.220  netmask 255.255.255.248  broadcast 78.47.37.223
        ether 08:60:6e:68:14:0a  txqueuelen 1000  (Ethernet)

eth0:4: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 78.47.37.221  netmask 255.255.255.248  broadcast 78.47.37.223
        ether 08:60:6e:68:14:0a  txqueuelen 1000  (Ethernet)

eth0:5: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 78.47.37.222  netmask 255.255.255.248  broadcast 78.47.37.223
        ether 08:60:6e:68:14:0a  txqueuelen 1000  (Ethernet)

eth0:: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 78.47.37.217  netmask 255.255.255.248  broadcast 78.47.37.223
        ether 08:60:6e:68:14:0a  txqueuelen 1000  (Ethernet)

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask ...