Hi, I was playing around with the various dhcp/radvd options of neutron. Very helpful was the matrix  that describes the combinations of ra and adress mode that can be configured.
For dhcpv6-stateful (ra & adress mode) it says: "VM obtains IPv6 address from dnsmasq using DHCPv6 stateful and optional info from dnsmasq using DHCPv6 stateful"  --> My assumption was that IP adresses and prefix are assigned via dnsmasq. But going this way, my instances got the right IP-Adress (great) but always the subnetmask /128, although I configured /64. Dumping the traffic and having a look at dnsmasq logs the dhcp process from solicit to reply worked fine. I was using rhel7 for guest and host and dnsmasq 2.68. I googled around and found some hints, that dhcpv6 does not support prefix delegation. Seems like that it is the job of the radvd daemon  Is that true? And if so, what's the use case of configuring dhcpv6-stateful for ra and address mode?  http://specs.openstack.org/openstack/neutron-specs/specs/juno/ipv6-radvd-ra.html#rest-api-impact  https://lists.isc.org/pipermail/dhcp-users/2012-May/015446.html  http://serverfault.com/questions/528387/sending-netmask-and-gateway-route-with-dhcp-for-ipv6  https://supportforums.cisco.com/document/116221/part-1-implementing-dhcpv6-stateful-dhcpv6 -- Andreas (irc: scheuran) __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev