I installed Openstack by packastack --allinone (havana on fedora 19) on a single host (allinone) . Hence call it 'Openstack host' or 'host hosting a VM'

allinone generates 2 subnets : private and public. The private works fine between VMs n (based on netns)

I added floating IP to a VM upon launch (from the 'real' subnet of the host) by allocating from floating IP pool

I can ping the VM by its floating IP (and ssh to it) from the single host hosting the VM but not from an external

host (this case on the same real subnet) . The external host does not get response to 'arping' command when

addressing the VM (.139) but gets arping response from the host hosting the VM (.136) .

Also : I see that the VM (.139) appears in the arp table of the Openstack host (hosting the VM) .

Is it an Openstack host iptable issue . Can I flush it for simplicity ? Note that the netns of the Openstack has its own virtual iptable separate from that of the Openstack host

should an arp proxy be enabled and set for subnetting on the Openstack host for external communication to reach the VMs ?

Any other idea on the source of the problem and how to fix it ?