In 2009, it was approved the IEEE 802.11w-2009 to increase the security of management frames.
The option in the unifi controller is called Protected management frames (PMF)
The setting only applies to third-generation access points in the UniFi universe. Means that the following access points support PMF:
How to enable PMF (Protected management frames)
To enable protected management frames to follow the next steps.
- Settings -> Wireless Networks -> WLAN Group (upper right corner) click edit button:
- Click on advanced options
You can use optional or required to enable this option.