Secondary IPv6 subnet never gets configured in router

[Brian Haley]

I brought up a devstack recently, which creates both internal IPv4 and IPv6 subnets on a single network. To test a bug fix I wanted to add a secondary IPv6 subnet on the network, so using Horizon I did that (since a subnetpool was already configured), such that:

$ neutron net-list --field name --field subnets
+---------+-----------------------------------------------------------+
| name | subnets |
+---------+-----------------------------------------------------------+
| public | 32df3f47-2cc0-491f-a9dc-6a9b06287444 |
| | ca7291e9-0470-49fe-80a7-63eddd73b338 |
| private | ecaa0a78-646a-46fe-9846-996eddf70cf1 2001:db8:8000:1::/64 |
| | afa2f586-4f8c-4951-800f-8f82bb37bc8c 2001:db8:8000::/64 |
| | dd467ff5-5c9a-4cfe-91c9-fb788fc7ff40 10.0.0.0/24 |
+---------+-----------------------------------------------------------+

The 2001:db8:8000:1::/64 never got configured in my router, although it does show up in the DB.

It's not in the namespace or radvd.conf file, so VMs don't autoconfigure it.

$ sudo ip netns exec qrouter-f76baa3f-5881-4c49-8e72-cef86fa03166 ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
46: qr-7f0792c8-39: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450
    link/ether fa:16:3e:73:90:28 brd ff:ff:ff:ff:ff:ff
    inet 10.0.0.1/24 brd 10.0.0.255 scope global qr-7f0792c8-39
       valid_lft forever preferred_lft forever
    inet6 fe80::f816:3eff:fe73:9028/64 scope link
       valid_lft forever preferred_lft forever
49: qr-936fd0dc-71: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450
    link/ether fa:16:3e:ed:78:be brd ff:ff:ff:ff:ff:ff
    inet6 2001:db8:8000::1/64 scope global
       valid_lft forever preferred_lft forever
    inet6 fe80::f816:3eff:feed:78be/64 scope link
       valid_lft forever preferred_lft forever

And here's the two subnet's info, which seems pretty identical except for the prefix:

$ neutron subnet-show ipv6-private-subnet
+-------------------+-----------------------------------------------------------------------------+
| Field | Value |
+-------------------+-----------------------------------------------------------------------------+
| allocation_pools | {"start": "2001:db8:8000::2", "end": "2001:db8:8000:0:ffff:ffff:ffff:ffff"} |
| cidr | 2001:db8:8000::/64 |
| created_at | 2016-10-05T20:50:32Z |
| description | |
| dns_nameservers | |
| enable_dhcp | True |
| gateway_ip | 2001:db8:8000::1 |
| host_routes | |
| id | afa2f586-4f8c-4951-800f-8f82bb37bc8c |
| ip_version | 6 |
| ipv6_address_mode | slaac |
| ipv6_ra_mode | slaac |
| name | ipv6-private-subnet |
| network_id | f6b05fa1-29e4-4e2f-96ae-d9f4cdededea |
| project_id | df427083b46c400e956f66ba952b3b55 |
| revision_number | 2 |
| service_types | |
| subnetpool_id | 79e46698-bc5a-4458-bed9-6d2a47d7876c |
| tenant_id | df427083b46c400e956f66ba952b3b55 |
| updated_at | 2016-10-05T20:50:32Z |
+-------------------+-----------------------------------------------------------------------------+

$ neutron subnet-show ipv6-subnet-2
+-------------------+-------------------------------------------------------------------------------+
| Field | Value |
+-------------------+-------------------------------------------------------------------------------+
| allocation_pools | {"start": "2001:db8:8000:1::2", "end": "2001:db8:8000:1:ffff:ffff:ffff:ffff"} |
| cidr | 2001:db8:8000:1::/64 |
| created_at | 2016-10-05T20:59:56Z |
| description | |
| dns_nameservers | |
| enable_dhcp | True |
| gateway_ip | 2001:db8:8000:1::1 |
| host_routes | |
| id | ecaa0a78-646a-46fe-9846-996eddf70cf1 |
| ip_version | 6 |
| ipv6_address_mode | slaac |
| ipv6_ra_mode | slaac |
| name | ipv6-subnet-2 |
| network_id | f6b05fa1-29e4-4e2f-96ae-d9f4cdededea |
| project_id | df427083b46c400e956f66ba952b3b55 |
| revision_number | 2 |
| service_types | |
| subnetpool_id | 79e46698-bc5a-4458-bed9-6d2a47d7876c |
| tenant_id | df427083b46c400e956f66ba952b3b55 |
| updated_at | 2016-10-05T20:59:56Z |
+-------------------+-------------------------------------------------------------------------------+

[Brian Haley (brian-haley)]

Doh, I'm an idiot, john-davidge pointed out I forgot to add the router interface to this subnet, I should know better :)