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



10 thoughts on “OpenStack Havana and IPv6

  1. There are some problems in the on Controller that I don’t know how to modify the “_generate_ip” method. If modified original “_generate_ip” to “generate_ip_v4v6″ or not? Please post your code sources.

      • Hi, Shixiong
        First, Thank you for providing the code. It is helpful for me. Then, when I read the pdf of OpenStack Havana on IPv6, there are some problem that “Modified ‘__populate_subnet_for_ports’ in” on Contrller Node. There is an error that the KeyValue “ip_version” occurs. And I have no idea that “Modified ‘fixed_ips’ field for DEVICE_OWNER_ROUTER_GW port” and “Regular ‘fixed_ips’ field for ROUTER-INTERFACE port”. Please tell me how to modified these!!!

        Shen Wei.

  2. Hi,Shixiong Shang
    The white paper was so helpful to me ,but i have one issue,vm don’t install default route to link-local address of the
    interface by which router uses to send out Router Advertisement,can you explain to me?thank you!

    • Hi, Frank:

      Thank you for reaching out to us! There are several potential reasons that the VM won’t get default route installed. Can you see RA on your VM by tcpdump? Do you allow VM to receive and process IPv6 RA at interface level? I need more details to help you troubleshoot.

      Thanks again!


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