getting AP alert from prime Rason: Radio channel set.

[ziamcaccna]

Message: '802.11a/n' interface of AP 'abc' associated to controller 'xyz (192.168.1.10)' is down. Reason: Radio channel set.
Failure Source: abc, Interface 802.11a/n

WLC--

Model: AIR-CT5520-K9

Software version : 8.2.141.0

Prime--

Build - 3.1.0.0.132

Patch- PI3.1.7 maintenance release

device pack 16.0

[Leo Laohoo]

This is normal.  The radio has to be disabled when the radio channel &/or power needs to change.

[ziamcaccna]

Thank you. Can you please elaborate why o channel &/or power needs to change.or any doc which could help me understanding this.

[pwwiddicombe]

Default on a WLC is to run RRM, which does channel and power adjustments periodically to optimize the airspace the AP's reside in.  For instance, when you start adding a number of AP's, the A radios will all be set to channel 36, max power until RRM runs.  Then, depending on existing channels in use and how strong they are seen by each other, channels will change and power gets reduced.  (If you have a lonely AP that can't see any other AP's, it will stick with channel 36/power 1 (max).

You can set the frequency of DFC (channel) and TPC (power) adjustments; so you can run the (disruptive) DFC every 24 hours, say, at 10:00 pm...

[NareshV]

Do we have any impact when radio is disabled? What the best practice to reduce these kind of alerts?

Thanks,

Naresh

[pwwiddicombe]

You should only see these alerts if there is a change in your wireless environment - i.e. too many neighbors on the same channel.  Clients will "follow" the AP or switch to another one in the area, and should not see any issues;'similar to the way clients normally roam from AP to AP.

The exception to this is if it was a detected "RADAR" hit in which case (by law) the AP has to change channel; in which case it is possible there is NOT an AP on another channel nearby.  In this case, this should be a one-time event, as the AP would have moved away from the RADAR-affected channel and should not return to it.  (read up on DFS).