Manage IP addresses

updated: 2017-06-18 09:18

Manage IP addresses

Manage IP addresses¶

Each instance has a private, fixed IP address that is assigned when the instance is launched. In addition, an instance can have a public or floating IP address. Private IP addresses are used for communication between instances, and public IP addresses are used for communication with networks outside the cloud, including the Internet.

Note

When creating and updating a floating IP, only consider IPv4 addresses on both the floating IP port and the internal port the floating IP is associated with. Additionally, disallow creating floating IPs on networks without any IPv4 subnets, since these floating IPs could not be allocated an IPv6 address.

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 Allocate a floating address to an instance section in the OpenStack End User Guide.
For details on creating public networks using OpenStack Networking (neutron), refer to Advanced features through API extensions. No floating IP addresses are created by default in OpenStack Networking.

List addresses for all projects¶

To list all floating IP addresses for all projects, run:

$ openstack floating ip list
+--------------------------------------+---------------------+------------------+------+
| ID                                   | Floating IP Address | Fixed IP Address | Port |
+--------------------------------------+---------------------+------------------+------+
| 89532684-13e1-4af3-bd79-f434c9920cc3 | 172.24.4.235        | None             | None |
| c70ad74b-2f64-4e60-965e-f24fc12b3194 | 172.24.4.236        | None             | None |
| ea3ebc6d-a146-47cd-aaa8-35f06e1e8c3d | 172.24.4.229        | None             | None |
+--------------------------------------+---------------------+------------------+------+

Create floating IP addresses¶

To create a floating IP addresses, run:

$ openstack floating ip create --fixed-ip-address <fixed-ip-address> <network>

For example:

$ openstack floating ip create --fixed-ip-address 192.168.1.56 NETWORK

Note

You should use a free IP addresses that is valid 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.

Delete floating IP addresses¶

To delete a floating IP address, run:

$ openstack floating ip delete FLOATING_IP

For example:

$ openstack floating ip delete 192.168.1.56

updated: 2017-06-18 09:18

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