Gabriele - nothing in neutron should be using proxy ARP, but there could be something mis-configured, or a piece or network equipment doing it.
Something I've seen before is that when the subnet was created in neutron a block of IPs maybe wasn't removed for non-neutron entities. For example, 'openstack subnet create' needs a '--allocation-pool start=10.0.0.15,end=10.0.0.254' since some pieces of gear are going to be using some of the IPs. I don't think this is the case but I've seen it happen when a switch was hard-coded with an IP and neutron assigned the IP to a system.
Gabriele - nothing in neutron should be using proxy ARP, but there could be something mis-configured, or a piece or network equipment doing it.
Something I've seen before is that when the subnet was created in neutron a block of IPs maybe wasn't removed for non-neutron entities. For example, 'openstack subnet create' needs a '--allocation-pool start=10. 0.0.15, end=10. 0.0.254' since some pieces of gear are going to be using some of the IPs. I don't think this is the case but I've seen it happen when a switch was hard-coded with an IP and neutron assigned the IP to a system.