OpenStack Havana and IPv6

OpenStack Havana (8th release) is available on October 17 with 400+ new features. However, it brought very little excitement for IPv6 fans: users still cannot launch IPv6-based VMs.

After running out of patience, we immersed ourselves in the lab for several weeks and achieved the following goals:

  • All OpenStack infrastructure nodes communicated with each other by IPv6
  • User could spin up dual-stack VMs in multi-tenant environment
  • VMs gained connectivity to existing IPv6 network beyond OpenStack boundary

Although Havana release note didn’t mention any IPv6 limitations, what we found were:

  • Router Announcement was not sent to internal tenant network by default
  • DHCP process was bound to IP other than default gateway of tenant network
  • Neighbor Discovery packets were dropped by default by ip6tables filter rules
  • NAT and GARP were turned on for IPv6 subnets. Not desirable!

More details can be found in our whitepaper published at