The L3 API in OpenStack Networking supports multiple floating IP pools. In OpenStack Networking, a floating IP pool is represented as an external network, and a floating IP is allocated from a subnet associated with the external network. You can associate a L3 agent with multiple external networks.

To enable the L3 agent to support multiple external networks, edit the l3_agent.ini file and leave the gateway_external_network_id and external_network_bridge parameters unset:

handle_internal_only_routers = True
gateway_external_network_id =
external_network_bridge =

Restart L3 Agent:
# service neutron-l3-agent restart