Wireless Access

Contributor II

AP changing channel/power for a reason

Hi Guys,


            i had some complaints about some clients that unable to connect to our WLAN, when i checked one AP i had the below output:

show ap arm history ap-name AP-19


Interface :wifi0
ARM History
Time of Change Old     Channel New Channel Old Power New Power Reason
-------------- -----------        ----------- --------- --------- ------
2016-04-21 06:09:42      36+                 153-           24             24                E
Interface :wifi1
ARM History
Time of Change                          Old Channel New Channel Old Power New Power Reason
-------------- -----------                           ----------- --------- --------- ------
2016-06-07 04:36:29                         11                1                      24                  24           I
2016-06-07 04:27:36                          6                11                     24                  24           M
2016-06-06 23:33:14                           1                6                      24                  24           M
2016-06-06 06:55:36                           11              1                      24                  24            I
2016-06-06 06:34:24                             6              11                    24                   24           M
2016-06-06 03:14:30                            1                6                     24                    24           E

First : what does the reason tab implies example:


I : for interference, is it wifi interference or non-wifi interference.

M: Empty channel, what does that mean?

E: error threshold exceeded, what does that mean and how to fix or change the value?


Secondly: how can i go about fixing the problem, change the power values?


OS: 6.3

AP: 105


Thanks for the help,



Guru Elite

Re: AP changing channel/power for a reason

1.  What regulatory domain is this?

2.  The power of 24 is too, too high.  The ARM min tx should be 12 and the ARM max should be 18.

3.  Means that too many frames have been observed with Errors on its current channel, so it is changing.

4.  M means it saw little traffic on a channel, so it decided to change to it.


The power should be turned down, period, to start.  See if that makes a difference.

*Answers and views expressed by me on this forum are my own and not necessarily the position of Aruba Networks or Hewlett Packard Enterprise.*
ArubaOS 8.3 User Guide
InstantOS 8.3 User Guide
Airheads Knowledgebase
Airheads Learning Videos
Contributor II

Re: AP changing channel/power for a reason

Thanks Collins,


                          i have reduced the EIRP and its working fine now.



Search Airheads
Showing results for 
Search instead for 
Did you mean: