To Reproduce Steps to reproduce the behavior:

1. Deploy overcloud, create external network, deploy instances, associate FIPs, etc
2. Go to Network > Floating IPs
3. Pick any available FIP and click on "Associate"
4. The "Manage Floating IP Associations" window appears.
   1. The IP Address field is pre-filled, leave as is
   2. The "Port to be associated" field offers a list, which includes FIPs that are already assigned somewhere else.

Expected behavior

• The "Port to be associated" list should not include ports that already have a FIP associated, since they are not actually available for the operation.

Screenshots

• List of all FIPs to choose from, including those that are unavailable
  
• Selecting one of those FIPs results in an error
  

Bug impact

• No functional impact, although the list of ports grows unnecessarily long the more FIPs are assigned to the project, which is bothersome

Known workaround

• No workaround for the web interface