The following is taken from the Cisco NetPro discussion forum, regarding cisco wireless access points which are dropping clients randomly. I thought it might interest somone so I repost the issue here:

Problem:
I have anywhere from 5-20 access points drop up and down throughout the day out of a total of around 200. I am currently trying to go through and figure out why we our access points are having some many issues and how I might be able to resolve them.

One of the logs that I commonly see is:

AP ‘exp-p13′, interface ’802.11a’ on Controller ’10.2.192.25′. Channel changed to ’44′ from ’60′ due to ‘None’. Interference Energy before update is ’0′ and after update is ’0′. Noise before update is ’0′ and after update is ’0′. Interference before update is ’0′ and after update is ’0′.

Is there anyway to determine what the cause of this is?

Controller Firmware: 4.2.130.0.
AP Model AIR-LAP1242AG-A-K9
IOS Version 12.4(10b)JA4

Solution:
Sounds like it’s just the Radio Resource Management (RRM) on the controller. You can disable this if it’s dropping clients. Go to the wireless tab, look on the left, and click on the 802.11a/n or 802.11b/g/n dropdown. Then click on the RRM dropdown, and click on Auto RF.

My advice is to change both power and channel assignment algorithms to “On Demand”. You can invoke them as needed to maintain an optimum network. By default, it automatically invokes the update every 10 minutes.

Related posts:

1. Cisco Aironet Wireless for Challenging Environments
2. Next Generation Wireless – Wireless Mesh Solution