Wireless Access

Contributor II Random Disconnects

Last Sunday we upgraded our controllers from version to  We liked the new licensing, and the ability to hook AP-225's into the network.


We currently run 6 M3 blades in two 6000 chassis.  Master, Backup, and 4 local controllers.


Since the upgrade, we've had numerous issues with random client disconnects, and overall inability to communicate anywhere from 5 seconds to 30 seconds.  I originally thought the problem was with Client Match, as it seemed that the clients were attempting to connect to a different AP several times per minute.  During these peroids, the clients would go offline for 5-20 seconds (unable to ping IP address).


I believe now the problem is more widespread and affects even less AP dense areas (our high schools have an AP about every 100 feet).  We have entire classes where half of the class cannot connect, or stay connected throughout the period.  


One of the most prominate places utilizes Dell laptops in a mobile lab.  The AP is directly outside of the room, and only half of the clients can connect (seemingly random amount).  I've seen the issue on OS X machines, Windows 7, and Androids.


We didn't have any of these issues before the upgrade to


Is anyone else experiencing issues like these with  I currently have an open ticket with Aruba Support, but wanted to see if others in the community are having these types of issues.


Thanks in advance!


Re: Random Disconnects

What type of network(s) are being affected?

e.g.  OPEN?   802.1x?  WPA2?



Frequent Contributor II

Re: Random Disconnects

I've heard similar reports from Windows 7/8, OS X and iDevices. I'm currently running on an 802.1x network.


Re: Random Disconnects

If its a dot1x network... I would recommend running this command, and  checking the two parameters below.


The key here is to see how many transcations are going on and are queued when the issue hits.




(Controller) #show dot1x counters 


       802.1x Counters

Throttling Counters

Dot1x high watermark..................150

Dot1x low watermark...................100

Dot1x auth pass count.................0

Dot1x auth fail count.................0

Double dot1x context init counts......0/0

Active dot1x station count............0                     <-----------  Check this

Max collisions in active table........0

Pending station count.................0                         <-----------  Check this

Max collisions in pending table...….0

Frequent Contributor II

Re: Random Disconnects

Can you provide an example of acceptable and unacceptable numbers?


I'm currently seeing:


Active dot1x station count............147
Max collisions in active table........5 <----------------------what's this?
Pending station count.................0

Contributor II

Re: Random Disconnects

I've seen the issue on Open and 802.1x networks.  The only report we've had on the Open network was from the Android where it was connected just fine, disconnected for about 30 seconds, and reconnected, all while the user was in the same location.


Here is a copy of our dot1x counters:


802.1x Counters
Throttling Counters
Dot1x high watermark..................70
Dot1x low watermark...................40
Dot1x auth pass count.................121647
Dot1x auth fail count.................0
Double dot1x context init counts......19337/19337
Active dot1x station count............22
Max collisions in active table........3
Pending station count.................0
Max collisions in pending table.......0

Contributor II

Re: Random Disconnects

Here's the support troubleshooting.  I thought the commands were very useful, and wanted to share:


#show clock


Note down the exact time of the issue happened ( The client disconnected and unable to connect to the network)


#show ap remote debug mgmt-frames client-mac <wireless device's mac address> ap-name <name of the AP client associated>


This will list the 802.11 management packets (Association Request, Association Response, Disassociation, and Deauth) for the specified wireless device.


#show log system all | include “<wireless device's mac address>


This command will show if the problem client is attempting to associate.  Look for the problem client MAC address.  It will also show to which AP the client MAC is attempting to associate.  Note the BSSID.


#show ap association client-mac “<wireless device's mac address>


Use the AP BSSID taken from the output of the previous command and user MAC.  This command can be used to verify if there are other users currently associated to this same AP thus helping to rule out infrastructure issues vs a single-client issue.



#show log errorlog all | include “<wireless device's mac address>”


This command can be used to determine if the RADIUS server is responding to client requests.  Look for excessive RADIUS timeouts or instances of the Aruba switch taking a RADIUS server out of service for the server hold-down timer.  (This indicates possible RADIUS server connectivity or performance issues and should be investigated as needed.)


#Show ap debug client-table ap-name <AP name where the wireless device is associated to>


In part of this CLI output it will display the wireless device’s Last_Rx_SNR, Tx_Rate, and Rx_Rate.    If the SNR is 10 or lower, then the wireless device is far away from the AP. If the Tx_Rate or Rx_Rate are 1, 2, or 6 then the device may be experiencing interference or is far away from the AP


#show ip mobile trail <wirelessMACaddress>


This command displays the mobility history of a given client.  This can be used to check for the frequency of roaming especially if the user has been stationary.  If the client PC has been bouncing between APs due to driver issues, this can result in dropped WLAN connections.


#show user ip <ipaddr>


Investigate the following:  Channel Frame Retry Rate – 10-20% is normal, 30 is intermediate and 40% is critical.  This means 40% of the frames put to the air have been retransmitted.  This is a symptom of heavy interference or low signal strength.    Channel Noise – If channel noise is at a value of 65 or below then this is a critical interference level. 


#show ap debug radio-stats ap-name <name-of-ap client connected> radio <0>

#show ap debug radio-stats ap-name <name-of-ap client connected> radio <1>


From the above commands we can determine the current Noise Floor and the RSSI/SNR.


From these steps you can determine possible causes for disconnection such as roaming problems, low signal strength, roaming outside of the WLAN coverage area and most importantly, the presence or not of major sources of interference.


Re: Random Disconnects



Did you ever find out what caused this and how to solve this issue?


John Solberg

-ACMX #316 :: ACCX #902 :: ACSA
Aruba Partner Ambassador
Intelecom/NetNordic - Norway
Remember to Kudo if a post helped you! || Problem Solved? Click "Accept as Solution" in a post!
Contributor II

Re: Random Disconnects

We have not had a fix yet.  We still see the issue occasionally on  Support looked at it for several days, and never came up with a solution.

Frequent Contributor I

Re: Random Disconnects

Is the environement running a mixed of 11a/g/an/gn/ac end-devices?


Able to isolate the common symptoms for affected laptops?

"If there's a will, there's a way."
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