Comment 4 for bug 1393527

@Eran, step 1 and 2 above is fine. This bug addresses the following situation.
Now if you try to associate the subnet to a neutron router, you will be getting an error (i.e., Step 4 below).

Step 3: neutron router-create ipv6-router
Step 4: neutron router-interface-add ipv6-router tenant_a_provider_stateless_subnet
Bad router request: IPv6 subnet cb5629e8-1762-45d3-8102-cf691503ef83 configured to receive RAs from an external router cannot be added to Neutron Router.