UniFi - Network Controller: Association Failures

Different types of association failures are shown in the association failures widget on the bottom of the main page in the Unifi Controller. There are four different types of failures that are counted: 1) Association Timeout, 2) WPA Authentication Timeout/Failure, 3) "Blocked by Access Control" 4) DHCP Timeout/Failure.

Association failure tracking is in continuous improvement. For best results, upgrade to the newest firmware version. Association tracking was introduced in UniFi Access Point (UAP) firmware 3.9.28 (MAC ACL rejections was introduced in 3.9.26). This article provides information on which version certain tracking features were released. Not implemented yet on UAP models: Nano HD and HD-IW.

1) Association Timeout:

  • Counts the number of times WiFi association did not complete for any number of reasons. These reasons could include the AP rejecting the association, frames sent between the AP and client during the association process being missed, interference, etc. 
  • Available on UAP firmware 3.9.28 and newer. 

2) WPA Auth Timeout/Failure:

  • Counts the number of times WPA authentication (4-way handshake) did not complete.
  • Some common causes are:
    • Incorrect WPA password
    • Incorrect WPA Enterprise/RADIUS username or password
  • Available on UAP firmware 3.9.28 and newer.

3) Blocked By Access Control:

  • Counts the number of times probe requests and pre-WPA auth requests were rejected because of MAC ACL settings under SSID settings. 
  • Some common causes are:
    • A client blocked in the dashboard. In the UniFi Controller, go to Insights > Known Clients > Select "Blocked" and "All" for the time frame. 
    • A client is not whitelisted or on the blacklist under the SSID settings. Settings > Wireless Networks > MAC Filter.
  • Available on UAP firmware 3.9.26 and newer.

    NOTE: Association timeouts (first category) and blocked by access control are mutually exclusive: i.e. association timeouts do not include blocked by access control.

4) DHCP Timeout/Failure:

  • Counts number of times a client tried to acquire DHCP lease, but the process did not complete (client did not receive DHCP offer or ACK).
  • Common causes:
    • DHCP lease pool exhausted.
    • DHCP server unreachable or misconfigured.
  • Available on UAP Firmware 3.9.28 and newer.