Diagnosing association failure with your Ubiquiti UniFi Controller

From time to time, you may experience issues with clients connecting to UniFi access points. Here are some ways to diagnose potential problems from within the UniFi Network Controller.


It is possible that a DHCP server can run out of IP addresses to give out to clients. Wherever your DHCP server is located, check to see how many devices have been leased within a certain period of time. Also, make sure DHCP isn’t blocked by your router’s firewall in any way.

WiFi authentication failure

Sometimes, a WiFi authentication failure can be caused by a simple mistake on the client’s side. Check to make sure the password has been entered correctly. Also if you’re authenticating with RADIUS, make sure the user is in the database and their details are correct.

WiFi clients have been blocked

It is certainly possible that the clients in question might have been blocked by mistake. In the WebUI, head over to the Insights section, and select from the menu Known Clients and All to list any that may have been blocked.

Re-provision the UniFi AP

Re-provisioning your UniFi APs may help to solve the problem. Refer to this guide to learn more.

Update your AP firmware, if available

If there’s an update for your UniFi AP, go ahead and run it. It may help solve the problem, and fix any potential bug that may be causing it.