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Receiving the "Station [source MAC address] Associated with Encryption, then attempted to send an Unencrypted packet to [destination MAC address] (length length)" error message


You get this message when a client configured with no authentication settings  associates to an  access point configured with Open authentication with WEP or Open Authentication with  EAP.

Since the access point is configured with open authentication client initially associates . But later when it sends a packet with no encryption this message  is logged in the access point. Client might be another access point configured as a repeater or any wireless client. It can also happen in Bridge-Bridge topology.

Note: Even when a rogue client tries to associate you get this message . If so locate and remove the rogue. Chedck the Mac address in the error message to locate the rogue.

To address this issue,

  • Match  the security settings on the devices. 
  • Upgrade the firmware of the device.

Problem Type

Error message


AP 340, 350

AP 1200

BR 340

BR 350

WLAN adapters (wireless card) / ACU (Aironet Client Utility)

Version history
Revision #:
1 of 1
Last update:
‎06-22-2009 03:33 PM
Updated by: