98 lines
5.3 KiB
ReStructuredText
98 lines
5.3 KiB
ReStructuredText
..
|
|
Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
not use this file except in compliance with the License. You may obtain
|
|
a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
License for the specific language governing permissions and limitations
|
|
under the License.
|
|
|
|
|
|
Convention for heading levels in Neutron devref:
|
|
======= Heading 0 (reserved for the title in a document)
|
|
------- Heading 1
|
|
~~~~~~~ Heading 2
|
|
+++++++ Heading 3
|
|
''''''' Heading 4
|
|
(Avoid deeper levels because they do not render well.)
|
|
|
|
|
|
Keep DNS Nameserver Order Consistency In Neutron
|
|
================================================
|
|
|
|
In Neutron subnets, DNS nameservers are given priority when created or updated.
|
|
This means if you create a subnet with multiple DNS servers, the order will
|
|
be retained and guests will receive the DNS servers in the order you
|
|
created them in when the subnet was created. The same thing applies for update
|
|
operations on subnets to add, remove, or update DNS servers.
|
|
|
|
Get Subnet Details Info
|
|
-----------------------
|
|
::
|
|
|
|
changzhi@stack:~/devstack$ neutron subnet-list
|
|
+--------------------------------------+------+-------------+--------------------------------------------+
|
|
| id | name | cidr | allocation_pools |
|
|
+--------------------------------------+------+-------------+--------------------------------------------+
|
|
| 1a2d261b-b233-3ab9-902e-88576a82afa6 | | 10.0.0.0/24 | {"start": "10.0.0.2", "end": "10.0.0.254"} |
|
|
+--------------------------------------+------+-------------+--------------------------------------------+
|
|
|
|
changzhi@stack:~/devstack$ neutron subnet-show 1a2d261b-b233-3ab9-902e-88576a82afa6
|
|
+------------------+--------------------------------------------+
|
|
| Field | Value |
|
|
+------------------+--------------------------------------------+
|
|
| allocation_pools | {"start": "10.0.0.2", "end": "10.0.0.254"} |
|
|
| cidr | 10.0.0.0/24 |
|
|
| dns_nameservers | 1.1.1.1 |
|
|
| | 2.2.2.2 |
|
|
| | 3.3.3.3 |
|
|
| enable_dhcp | True |
|
|
| gateway_ip | 10.0.0.1 |
|
|
| host_routes | |
|
|
| id | 1a2d26fb-b733-4ab3-992e-88554a87afa6 |
|
|
| ip_version | 4 |
|
|
| name | |
|
|
| network_id | a404518c-800d-2353-9193-57dbb42ac5ee |
|
|
| tenant_id | 3868290ab10f417390acbb754160dbb2 |
|
|
+------------------+--------------------------------------------+
|
|
|
|
Update Subnet DNS Nameservers
|
|
-----------------------------
|
|
::
|
|
|
|
neutron subnet-update 1a2d261b-b233-3ab9-902e-88576a82afa6 \
|
|
--dns_nameservers list=true 3.3.3.3 2.2.2.2 1.1.1.1
|
|
|
|
changzhi@stack:~/devstack$ neutron subnet-show 1a2d261b-b233-3ab9-902e-88576a82afa6
|
|
+------------------+--------------------------------------------+
|
|
| Field | Value |
|
|
+------------------+--------------------------------------------+
|
|
| allocation_pools | {"start": "10.0.0.2", "end": "10.0.0.254"} |
|
|
| cidr | 10.0.0.0/24 |
|
|
| dns_nameservers | 3.3.3.3 |
|
|
| | 2.2.2.2 |
|
|
| | 1.1.1.1 |
|
|
| enable_dhcp | True |
|
|
| gateway_ip | 10.0.0.1 |
|
|
| host_routes | |
|
|
| id | 1a2d26fb-b733-4ab3-992e-88554a87afa6 |
|
|
| ip_version | 4 |
|
|
| name | |
|
|
| network_id | a404518c-800d-2353-9193-57dbb42ac5ee |
|
|
| tenant_id | 3868290ab10f417390acbb754160dbb2 |
|
|
+------------------+--------------------------------------------+
|
|
|
|
As shown in above output, the order of the DNS nameservers has been updated.
|
|
New virtual machines deployed to this subnet will receive the DNS nameservers
|
|
in this new priority order. Existing virtual machines that have already been
|
|
deployed will not be immediately affected by changing the DNS nameserver order
|
|
on the neutron subnet. Virtual machines that are configured to get their IP
|
|
address via DHCP will detect the DNS nameserver order change
|
|
when their DHCP lease expires or when the virtual machine is restarted.
|
|
Existing virtual machines configured with a static IP address will never
|
|
detect the updated DNS nameserver order.
|