Create a Network for Subnet

# cd efa

# openstack network create net1 \ --provider-network-type vlan \ --provider-physical-network physnet1 \ --provider-segment 101 

# openstack subnet create subnet1 \ --network net1 \ --subnet-range 20.0.5.0/24 parent_mac="$( openstack port show port0 | awk '/ mac_address / { print $4 }' )" 

# openstack port create port1 \ --network net1 --mac-address  "$parent_mac”