[openstack-dev] [Neutron] [IPv6] [radvd] Advertise tenant prefixes from router to outside

Vladimir Eremin veremin at mirantis.com
Thu Dec 17 20:30:33 UTC 2015


For now, when end user is creating IPv6-enabled tenant network and attaching it to the virtual router, there is only way to set up external infrastructure to put traffic back to the router is using DHCPv6 PD[1], unfortunately, it’s not working at all[2]. Other methods like implementing BGP is still in development.

BTW, in IPv6 Router Advertisements we have an option called Route Information Option, RA-RIO[3] to advertise more specific routes from gateway. We could easily append a section like next one to advertise tenant prefix 2001:db8:1::/64 to public network. And if provider network router outside OpenStack will be configured to accept these.

interface qg- {
        AdvDefaultLifetime 0;
        route 2001:db8:1::/64 {

Cisco accepts it by default AFAIK, linux needs a sysctl net.ipv6.conf.*.accept_ra_rt_info_max_plen set to 64.

Moreover, enabling receiving RA-RIO prefixes in router namespaces allows routers communicate by themselves.

I’ve done PoC patch for it https://gist.github.com/yottatsa/8282e670da16934960b3

[1]: http://specs.openstack.org/openstack/neutron-specs/specs/kilo/ipv6-prefix-delegation.html
[2]: https://bugs.launchpad.net/neutron/+bug/1505316
[3]: https://tools.ietf.org/html/rfc4191

With best regards,
Vladimir Eremin,
Fuel Deployment Engineer,
Mirantis, Inc.

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