Each instance has a private, fixed IP address (assigned when launched) and can also have a public, or floating, address. Private IP addresses are used for communication between instances, and public addresses are used for communication with networks outside the cloud, including the Internet. By default, both administrative and end users can associate floating IP addresses with projects and instances. You can change user permissions for managing IP addresses by updating the /etc/nova/policy.json file. For basic floating-IP procedures, refer to the Manage IP Addresses section in the OpenStack End User Guide. For details on creating public networks using OpenStack Networking (neutron), refer to the OpenStack Cloud Administrator Guide. No floating IP addresses are created by default in OpenStack Networking. As an administrator using legacy networking (nova-network), you can use the following bulk commands to list, create, and delete ranges of floating IP addresses. These addresses can then be associated with instances by end users: List addresses for all projects To list all floating IP addresses for all projects, run: $ nova floating-ip-bulk-list +------------+---------------+---------------+--------+-----------+ | project_id | address | instance_uuid | pool | interface | +------------+---------------+---------------+--------+-----------+ | None | 172.24.4.225 | None | public | eth0 | | None | 172.24.4.226 | None | public | eth0 | | None | 172.24.4.227 | None | public | eth0 | | None | 172.24.4.228 | None | public | eth0 | | None | 172.24.4.229 | None | public | eth0 | | None | 172.24.4.230 | None | public | eth0 | | None | 172.24.4.231 | None | public | eth0 | | None | 172.24.4.232 | None | public | eth0 | | None | 172.24.4.233 | None | public | eth0 | | None | 172.24.4.234 | None | public | eth0 | | None | 172.24.4.235 | None | public | eth0 | | None | 172.24.4.236 | None | public | eth0 | | None | 172.24.4.237 | None | public | eth0 | | None | 172.24.4.238 | None | public | eth0 | | None | 192.168.253.1 | None | test | eth0 | | None | 192.168.253.2 | None | test | eth0 | | None | 192.168.253.3 | None | test | eth0 | | None | 192.168.253.4 | None | test | eth0 | | None | 192.168.253.5 | None | test | eth0 | | None | 192.168.253.6 | None | test | eth0 | +------------+---------------+---------------+--------+-----------+ Bulk create floating IP addresses To create a range of floating IP addresses, run: $ nova floating-ip-bulk-create [--pool POOL_NAME] [--interface INTERFACE] RANGE_TO_CREATE For example: $ nova floating-ip-bulk-create --pool test 192.168.1.56/29 By default, floating-ip-bulk-create uses the public pool and eth0 interface values. You should use a range of free IP addresses that is correct for your network. If you are not sure, at least try to avoid the DHCP address range: Pick a small range (/29 gives an 8 address range, 6 of which will be usable) Use nmap to check a range's availability. For example, 192.168.1.56/29 represents a small range of addresses (192.168.1.56-63, with 57-62 usable), and you could run the command nmap -sn 192.168.1.56/29 to check whether the entire range is currently unused. Bulk delete floating IP addresses To delete a range of floating IP addresses, run: $ nova floating-ip-bulk-delete RANGE_TO_DELETE For example: $ nova floating-ip-bulk-delete 192.168.1.56/29