Controller Based WLANs

Answer- Internal deauth is nothing but When driver detects the client ageout of sta, or tx failure, driver sends up SAPCP_AGEOUT to ask stm to clean up the client.
STM forms an internal deauth to tell driver to clean up the node without sending deauth OTA. 
 
From below logs, we could notice client is been de-authed due to reason Internal.

(Aruba) #show ap client trail-info 24:fd:52:de:xx:xx 
 
Client Trail Info
-----------------
MAC                BSSID              ESSID    AP-name      VLAN  Deauth Reason    Alert
---                -----              -----    -------      ----  -------------    -----
24:fd:52:de:xx:xx  18:64:72:xx:xx:xx  Testlab  Testlab-ap    212   Internal deauth  Internal deauth
 
Deauth Reason
-------------
Reason                               Timestamp
------                               ---------
Internal deauth                      Nov 11 03:34:18
Internal deauth                      Nov 11 01:20:28
STA has roamed to another AP         Nov 11 00:40:37
STA has roamed to another AP         Nov 11 00:15:17
Internal deauth                      Nov 10 15:34:58
Internal deauth                      Nov 10 13:34:58
Internal deauth                      Nov 10 12:40:55
STA has left and is deauthenticated  Nov 10 12:40:31
Internal deauth                      Nov 10 12:23:15
Internal deauth                      Nov 10 12:06:28

Num Deauths:10