When a subnet is created with more than one DNS the order they were specified is not retained.
One reason this is an issue is that the user wants to split the DNS usage evenly across the available DNS nameservers to lessen the probability of the DNS lookups causing a performance bottleneck.
Here's the commands to recreate:
[root@rhel62 neutron]# neutron net-create mynet
Created a new network:
+---------------------------+--------------------------------------+
| Field | Value |
+---------------------------+--------------------------------------+
| admin_state_up | True |
| id | 4844005a-88b5-4c33-91de-3a116b2aea97 |
| name | mynet |
| provider:network_type | local |
| provider:physical_network | |
| provider:segmentation_id | |
| shared | False |
| status | ACTIVE |
| subnets | |
| tenant_id | 1018bf40fe164937956983bf78b3288d |
+---------------------------+--------------------------------------+
[root@rhel62 neutron]# neutron subnet-create --dns-nameserver 192.168.8.1 --dns-nameserver 192.168.1.1 mynet 192.168.1.0/24
Created a new subnet:
+------------------+--------------------------------------------------+
| Field | Value |
+------------------+--------------------------------------------------+
| allocation_pools | {"start": "192.168.1.2", "end": "192.168.1.254"} |
| cidr | 192.168.1.0/24 |
| dns_nameservers | 192.168.1.1 |
| | 192.168.8.1 |
| enable_dhcp | True |
| gateway_ip | 192.168.1.1 |
| host_routes | |
| id | 4448954b-d676-451b-a34c-4e76c8616397 |
| ip_version | 4 |
| name | |
| network_id | 4844005a-88b5-4c33-91de-3a116b2aea97 |
| tenant_id | 1018bf40fe164937956983bf78b3288d |
+------------------+--------------------------------------------------+
[root@rhel62 neutron]# neutron subnet-show 4448954b-d676-451b-a34c-4e76c8616397
+------------------+--------------------------------------------------+
| Field | Value |
+------------------+--------------------------------------------------+
| allocation_pools | {"start": "192.168.1.2", "end": "192.168.1.254"} |
| cidr | 192.168.1.0/24 |
| dns_nameservers | 192.168.1.1 |
| | 192.168.8.1 |
| enable_dhcp | True |
| gateway_ip | 192.168.1.1 |
| host_routes | |
| id | 4448954b-d676-451b-a34c-4e76c8616397 |
| ip_version | 4 |
| name | |
| network_id | 4844005a-88b5-4c33-91de-3a116b2aea97 |
| tenant_id | 1018bf40fe164937956983bf78b3288d |
+------------------+--------------------------------------------------+
dns_nameservers ordering has never been guaranteed. This seems like a feature to consider for Icehouse.