C.5. Subnets

A subnet is the basic unit by which network settings are applied to hosts in a deployment. The rhel-osp-installer script creates a default subnet based on the values you specify. You can also manually create new subnets entries to map complex networking setups. Later, when you create deployments, you can assign certain types of network traffic to specific subnets and configure the network interfaces on hosts to use specific subnets.


The settings for subnets created in the user interface are provided for reference only, and do not update the DHCP or DNS settings on the machine hosting the installer.
Create a new subnet to carry network traffic.

Procedure C.8. Creating a Subnet

  1. From the title bar in the main screen of the user interface, click InfrastructureSubnets.
  2. Click New Subnet.
  3. Configure general subnet details:
    1. Enter a name for the subnet in the Name field.
    2. Enter the network address of the subnet in the Network address field.
    3. Enter the network mask for the subnet in the Network mask field.
    4. Enter the address of a gateway in the Gateway address field.
    5. Enter the address of the primary DNS server in the Primary DNS server field.
    6. Enter the address of the secondary DNS server, if any, in the Secondary DNS server field.
    7. Select the IP address management source from the IPAM list. If the subnet contains a DHCP server, select DHCP. If no DHCP capability exists on the subnet, select Internal DB and the installer manages the IP address assignment and records IP addresses in its internal database. Select None for no IPAM management.
    8. Optionally, enter the start of the IP address range that the installer can auto-suggest for hosts in the Start of IP range field.
    9. Optionally, enter the end of the IP address range that the installer can auto-suggest for hosts in the End of IP range field.
    10. Optionally, enter the ID of a VLAN for the subnet.
    11. Select the default boot mode for interfaces assigned to the subnet from the Boot mode list. This sets the boot protocol for client network interfaces. Select DHCP to use the DHCP protocol or Static to manually assign IP address either through the host's network interface settings or using the installer's IPAM Internal Database option.
  4. Configure domain membership:
    1. Click the Domains tab.
    2. Select the check box for all domains of which the subnet is a member.
  5. Click the Capsules tab to view the capsule settings. A capsule acts as a proxy for certain installer services, such as DHCP, TFTP, and DNS.
    The Capsule settings are only required for the default subnet. This is because the installer uses this subnet for host provisioning and deployment of Red Hat OpenStack Platform services. Any new subnets added to the installer do not require Capsule settings.
  6. Click Submit.