flavor

Create a subnet on the network:

$ openstack subnet create --network provider \
  --allocation-pool start=START_IP_ADDRESS,end=END_IP_ADDRESS \
  --dns-nameserver DNS_RESOLVER --gateway PROVIDER_NETWORK_GATEWAY \
  --subnet-range PROVIDER_NETWORK_CIDR provider

Replace PROVIDER_NETWORK_CIDR with the subnet on the provider physical network in CIDR notation.

Replace START_IP_ADDRESS and END_IP_ADDRESS with the first and last IP address of the range within the subnet that you want to allocate for instances. This range must not include any existing active IP addresses.

Replace DNS_RESOLVER with the IP address of a DNS resolver. In most cases, you can use one from the /etc/resolv.conffile on the host.

Replace PROVIDER_NETWORK_GATEWAY with the gateway IP address on the provider network, typically the ”.1” IP address.

Example

The provider network uses 203.0.113.0/24 with a gateway on 203.0.113.1. A DHCP server assigns each instance an IP address from 203.0.113.101 to 203.0.113.250. All instances use 8.8.4.4 as a DNS resolver.

openstack subnet create --network provider --allocation-pool start=10.0.1.101,end=10.0.1.250 --dns-nameserver 8.8.4.4 --gateway 10.0.1.1 --subnet-range 10.0.1.0/24 provider

openstack subnet create --network selfservice \
  --dns-nameserver DNS_RESOLVER --gateway SELFSERVICE_NETWORK_GATEWAY \
  --subnet-range SELFSERVICE_NETWORK_CIDR selfservice

openstack subnet create --network selfservice \
  --dns-nameserver 8.8.4.4 --gateway 172.16.1.1 \
  --subnet-range 172.16.1.0/24 selfservice

openstack subnet create --network selfservice --dns-nameserver 8.8.4.4 --gateway 10.0.2.1 --subnet-range 10.0.2.0/24 selfservice