[neutron] dnsmasq refusing to provide ipv6 address over dhcpv6 after a server rebuild

Hi, I've filled this bug in Debian concerning our official image: https://bugs.debian.org/991613 tl;dr: When doing "openstack server rebuild", dnsmasq refuses to provide an ipv6 when the instance does a dhcpv6 request, because after a rebuild, the instance generates a different DUID. So I wonder if there's a way to fix this by configuring dnsmasq in some ways, maybe by telling it to not use the DUID at all. So far, I haven't found a way yet. Does anyone have a good answer to this problem? Ideally, I'd like to find a way to fix on both side (ie: OpenStack *AND* the official Debian image), so I can make sure to never encounter the issue ever again. Cheers, Thomas Goirand (zigo)