Procedure 8.8. Creating a Network Using the Command Line Interface

1. Use the source command to load the credentials of the administrative user.

   $ source ~/keystonerc_admin

2. Use the net-create action of the neutron command-line client to create a new provider network.
   The arguments passed to the neutron net-create command depend on whether you passed the value provider in the step Configuring OpenStack Networking in section Section 5.2, “Running PackStack Interactively” (or in the answer file if running PackStack non-interactively).
   Three options are available:
   1. if using an external bridge, use:

      $ neutron net-create EXTERNAL_NAME \ --router:external True \ --provider:network_type local 

   2. if using a flat provider external network, use:

      $ neutron net-create EXTERNAL_NAME \ --router:external True \ --provider:network_type flat --provider:physical_network PHYSICAL_NAME 

   3. if using a VLAN provider external network, use:

      $ neutron net-create EXTERNAL_NAME \ --router:external True \ --provider:network_type vlan --provider:physical_network PHYSICAL_NAME --provider:segmentation_id VLAN_TAG 

   Replace these strings with the appropriate values for your environment:
   • Replace EXTERNAL_NAME with a name for the new external network provider.
   • Replace PHYSICAL_NAME with a name for the physical network.
   • Replace VLAN_TAG with the VLAN tag that will be used to identify network traffic. The VLAN tag specified must have been defined by the network administrator.
   Take note of the unique external network identifier returned, this will be required in subsequent steps.

   Note

   When creating a provider network of type flat or VLAN, the physical network PHYSICAL_NAME must be listed in network_vlan_ranges on the node where neutron-server runs. If the physical network is not listed, running neutron net-create produces an error: Unknown provider:physical_network.

   To specify the physical network, for example when using linuxbridge, use the command:

   $ openstack-config --set /etc/neutron/plugin.ini \
        LINUX_BRIDGE network_vlan_ranges PHYSICAL_NAME 

   In this instance, no ranges of VLAN tags are required. This makes the physical networks available for flat or VLAN provider networks without making VLANs on those physical networks available as tenant networks.
3. Use the subnet-create action of the command line client to create a new subnet for the new external provider network.

   $ neutron subnet-create --gateway GATEWAY \
      --allocation-pool start=IP_RANGE_START,end=IP_RANGE_END \
      --disable-dhcp EXTERNAL_NAME EXTERNAL_CIDR

   Replace these strings with the appropriate values for your environment:
   • Replace GATEWAY with the IP address or hostname of the system that is to act as the gateway for the new subnet.
   • Replace IP_RANGE_START with the IP address that denotes the start of the range of IP addresses within the new subnet that floating IP addresses will be allocated from.
   • Replace IP_RANGE_END with the IP address that denotes the end of the range of IP addresses within the new subnet that floating IP addresses will be allocated from.
   • Replace EXTERNAL_NAME with the name of the external network the subnet is to be associated with. This must match the name that was provided to the net-create action in the previous step.
   • Replace EXTERNAL_CIDR with the Classless Inter-Domain Routing (CIDR) representation of the block of IP addresses the subnet represents. An example would be 192.168.100.0/24.
   Take note of the unique subnet identifier returned, this will be required in subsequent steps.

   Important

   The IP address used to replace the string GATEWAY must be within the block of IP addresses specified in place of the EXTERNAL_CIDR string but outside of the block of IP addresses specified by the range started by IP_RANGE_START and ended by IP_RANGE_END.

   The block of IP addresses specifed by the range started by IP_RANGE_START and ended by IP_RANGE_END must also fall within the block of IP addresses specified by EXTERNAL_CIDR.