[Rdo-list] enable dhcp on public network

Hi, This is my first post. Then forgive me if this is off-topic for this list and ignore it :) I need to assign public ips directly to my instances (not using floating ips). The packstack installation out-of-the-box do not enable dhcp on the public_net and then the ips are not assigned to the instances. How could I solve this? To be clear I need this: --------- eth0 (192.168.66.1) | | (br0 - 192.168.55.1) ----------------- VM (192.168.55.2) VM (192.168.55.3) VM get ip by dhcp and gw is 192.168.55.1 eth0 and br0 have ip_forwarding enabled. Thank you in advance. Regards, Victor