Subnet pools were introduced in the Kilo release of OpenStack and allow Neutron to control the assignment of IP address space upon subnet creation. Users can create subnet pools for use within their respective project only, or an administrator can create a subnet pool that is shared between projects. The use of subnet pools helps ensure that there is no IP address overlap between subnets and makes the creation of subnets easier for users. Subnet pools work best for self-service networks that are expected to be connected to Neutron routers and are ideal for cases where address scopes and Neutron's BGP Speaker functionality has been implemented.