The configuration supports one flat or multiple VLAN provider networks. For
simplicity, the following procedure creates one flat provider network.

#. Source the administrative project credentials.
#. Create a flat network.

   .. code-block:: console

      $ openstack network create --share --provider-physical-network provider \
        --provider-network-type flat provider1
      +---------------------------+-----------+-
      | Field                     | Value     |
      +---------------------------+-----------+
      | admin_state_up            | UP        |
      | mtu                       | 1500      |
      | name                      | provider1 |
      | port_security_enabled     | True      |
      | provider:network_type     | flat      |
      | provider:physical_network | provider  |
      | provider:segmentation_id  | None      |
      | router:external           | Internal  |
      | shared                    | True      |
      | status                    | ACTIVE    |
      +---------------------------+-----------+

   .. note::

      The ``share`` option allows any project to use this network. To limit
      access to provider networks, see :ref:`config-rbac`.

   .. note::

      To create a VLAN network instead of a flat network, change
      ``--provider-network-type flat`` to ``--provider-network-type vlan``
      and add ``--provider-segment`` with a value referencing the VLAN ID.

#. Create a IPv4 subnet on the provider network.

   .. code-block:: console

      $ openstack subnet create --subnet-range 203.0.113.0/24 --gateway 203.0.113.1 \
        --network provider1 --allocation-pool start=203.0.113.11,end=203.0.113.250 \
        --dns-nameserver 8.8.4.4 provider1-v4
      +-------------------+----------------------------+
      | Field             | Value                      |
      +-------------------+----------------------------+
      | allocation_pools  | 203.0.113.11-203.0.113.250 |
      | cidr              | 203.0.113.0/24             |
      | dns_nameservers   | 8.8.4.4                    |
      | enable_dhcp       | True                       |
      | gateway_ip        | 203.0.113.1                |
      | ip_version        | 4                          |
      | name              | provider1-v4               |
      +-------------------+----------------------------+

   .. important::

      Enabling DHCP causes the Networking service to provide DHCP which can
      interfere with existing DHCP services on the physical network
      infrastructure. Use the ``--no-dhcp`` option to have the subnet managed
      by existing DHCP services.

#. Create a IPv6 subnet on the provider network.

   .. code-block:: console

      $ openstack subnet create --subnet-range fd00:203:0:113::/64 --gateway fd00:203:0:113::1 \
        --ip-version 6 --ipv6-address-mode slaac --network provider1 \
        --dns-nameserver 2001:4860:4860::8844 provider1-v6
      +-------------------+------------------------------------------------------+
      | Field             | Value                                                |
      +-------------------+------------------------------------------------------+
      | allocation_pools  | fd00:203:0:113::2-fd00:203:0:113:ffff:ffff:ffff:ffff |
      | cidr              | fd00:203:0:113::/64                                  |
      | dns_nameservers   | 2001:4860:4860::8844                                 |
      | enable_dhcp       | True                                                 |
      | gateway_ip        | fd00:203:0:113::1                                    |
      | ip_version        | 6                                                    |
      | ipv6_address_mode | slaac                                                |
      | ipv6_ra_mode      | None                                                 |
      | name              | provider1-v6                                         |
      +-------------------+------------------------------------------------------+

   .. note::

      The Networking service uses the layer-3 agent to provide router
      advertisement. Provider networks rely on physical network infrastructure
      for layer-3 services rather than the layer-3 agent. Thus, the physical
      network infrastructure must provide router advertisement on provider
      networks for proper operation of IPv6.