Flexible Radio Assignment not working in IOS-XE 17.6.3?

[rschroeder1006]

Hi,

we have a bunch of C9800-40 controllers running IOS-XE 17.6.3. Yesterday, we discovered that from about 1.200 APs more than 50% were in monitor mode on the XOR radio. 2.4GHz coverage was very bad in some areas.

On the FRA page in the GUI (Configuration -> RRM -> FRA), it is set to enabled with 1h interval and medium sensitivity. But Last run is always "0 second(s) ago" and Last run time is always "0 second(s)". It seems, that FRA never runs although being enabled.

We did a "ap fra revert all auto" in the CLI and all APs switched back to 2.4GHz instantly on the XOR radio, so 2.4GHz coverage got better now. But nevertheless, FRA does not seem to run at all on the controllers running 17.6.3. I would expect some APs (mostly 2802i) going to 5GHz on the XOR radio but that does not happen anymore.

Has anything changed between 17.3.5b and 17.6.3? Or has anyone an idea about that? Reloading the controller(s) during the night did not help.

Thanks

Robin

[marce1000]

 - Could you verify the FRA interval with the CLI command  show ap fra (too) ? For the rest it is always useful to have a checkup of the C9800-40 configuration(s)  with the CLI command : show  tech wireless , have the output analyzed by  https://cway.cisco.com/tools/WirelessAnalyzer/  , please note do not use classical show tech-support (short version) , use the command denoted in green for Wireless Analyzer. Checkout the advisories.

 M.

[rschroeder1006]

FRA interval is 1 hour, see below:

wlc-8#show ap fra
FRA State : Enabled
FRA Freeze : Disabled
FRA Operation State : Up
FRA Sensitivity : medium (95%)
FRA Interval : 1 Hour(s)
Service Priority : Coverage
Client Aware FRA : Enabled
Client Select : 50%
Client Reset : 5%

As for the "show tech wireless" output, it is running, but takes a while. So I will use the analyzer later and come back with results.

[rschroeder1006]

Hi,

I analyzed the output of one of our controllers. The analyzer shows this interesting message:

Can you shed a light on it? I dont know what that means.

Thanks

[marce1000]

                >...APs with failed Interference Profile....

  Ref : https://community.cisco.com/t5/wireless/cisco-4402-lap1131-interference-profile-failed-for-base-radio/td-p/1633267 , check the first reply.

 M.

[Arshad Safrulla · Accepted solution]

FRA itself cannot change the role of the radio. Once FRA determines what to do with a Radio, it waits for 2 DCA runs before assigning a new role for XOR radio. So even though you set FRA interval to one hour it will not be able to change the radio role.

To immediately revert 

Use the command in privilege exex mode "ap fra revert all static 24ghz" 

Use "show ap fra" to verify

Once all radios are converted use "ap fra freeze " in config mode to freeze the radio's

[rschroeder1006 · Accepted solution]

We managed to solve our problems. As soon as we removed all AireOS controllers from the RF-Group (split the RF-Group into two groups), FRA began to work on the IOS-Controllers again. The GUI does not show that (Last run and Last run time are always 0), but the CLI does. And we see radios on 2.4GHz and 5GHz and in monitoring mode.

We have one controller with IOS-XE 17.9.1 (which is the automatically chosen Channel Assignment Leader for all bands), it shows real values for the timers, but the two controllers with 17.6.3/17.6.4 don't.

AireOS controllers are on 8.5IRCM release (we have a few hundreds of the C2600 series APs left...), so no TAC support anymore. Anyway, areas with older and newer APs are separated, so separate RF-Groups are okay for us.