Openstack Floating IP 使用流程：
# Step 1: create external flat network
$ neutron net-create --router:external --provider:network_type flat --provider:physical_network public_eth0 public_net
# Step 2: create subnet based on your reservation Here
$ neutron subnet-create --name public_eth0_subnet01 --allocation-pool start=192.168.1.100,end=192.168.1.119 --gateway 192.168.1.30 --disable-dhcp --ip-version 4 22d01ce7-b4c4-4af2-bc3c-9c3991903b4c 192.168.1.0/24
# Step 3: create a external router
$ neutron router-create router1
# Step 4: connect router1 with the private subnet via 'neutron router-interface-add <router-id> <private_subnet_id>'
$ neutron router-interface-add 2da62299-6e41-4b24-a1c7-a3d6cc4db1c8 fab94e2f-f7de-4bf6-8e9b-7ade0fcfad1f
# Step 5: Set the external public network as the router gateway 'neutron router-gateway-set <router-id> <public_subnet_id>'
$ neutron router-gateway-set 73a38db4-20f9-49ba-b855-472be1e2fd45 e0368da6-197e-4c46-bfd1-4897d61b519a
# Step 6: Create floating IP from public network 'neutron floatingip-create <public network id>'
$ neutron floatingip-create 1452712a-acb3-4341-a5ca-1d838eb2feb9
# Step 7: assicate the VM instance's port in private network to the newly created floating ip port
## get the port id of floating IP (in bold)
$ stack@openstack-wangp11-01:~$ neutron floatingip-list
+--------------------------------------+------------------+---------------------+--------------------------------------+
| id | fixed_ip_address | floating_ip_address | port_id |
+--------------------------------------+------------------+---------------------+--------------------------------------+
| a2316e0b-6d72-420f-8a23-f8421160d3d4 | | 192.168.1.102 | 75353e16-5a16-452e-b420-0ada719d625c |
+--------------------------------------+------------------+---------------------+--------------------------------------+
## get the port id of private interface attached to VM instance
$ stack@openstack-wangp11-01:~$ neutron port-list
+--------------------------------------+------+-------------------+--------------------------------------------------------------------------------------+
| id | name | mac_address | fixed_ips |
+--------------------------------------+------+-------------------+--------------------------------------------------------------------------------------+
| 16a3e39c-48ef-4d4d-bc8a-96b27da7ff3c | | fa:16:3e:c1:24:51 | {"subnet_id": "e0368da6-197e-4c46-bfd1-4897d61b519a", "ip_address": "192.168.1.100"} |
| 616d03cd-df6a-465f-a23a-b6bf46e55f7a | | fa:16:3e:48:2e:7f | {"subnet_id": "fab94e2f-f7de-4bf6-8e9b-7ade0fcfad1f", "ip_address": "192.168.46.4"} |
| 713e4541-7d22-4403-b828-94d714d94ec0 | | fa:16:3e:af:43:7b | {"subnet_id": "fab94e2f-f7de-4bf6-8e9b-7ade0fcfad1f", "ip_address": "192.168.46.2"} |
| 75353e16-5a16-452e-b420-0ada719d625c | | fa:16:3e:23:11:db | {"subnet_id": "fab94e2f-f7de-4bf6-8e9b-7ade0fcfad1f", "ip_address": "192.168.46.3"}