FRA Recalculation on a single AP

[Gehrig_W]

Hello Cisco-Experts,

we have activated FRA on our 5520-WLCs with hundreds of APs with good success.

I would like to revert a single 3800-AP from serving dual 5-GHz back to Auto to recalculate FRA on it.

But the command "config advanced fra revert" can not be done for a single AP.

I have changed the AP's dual band radio back to "Auto", "Client Serving"  and "2.4GHz"  via the GUI, but

after the next run of FRA after one hour, no change happened:

MIZ-AP367 08:4f:a9:ac:5a:a0 0 2.4GHz None None None

Do I have to wait longer ?

Or is it not possible to revert back a single AP from FRA ?

Please check.

Thank You

Wini

[Arshad Safrulla · Accepted solution]

You need to set the Radio Role Assignment to manual, then only AP will be taken out from the FRA pool. Once you do this there FRA will not impact the XOR radio. YOu have to manually set it.

Recalculating the FRA, needs 2 DCA runs. So if you want auto calculation you will need to wait for 2 DCA runs (Depends on the DCA timer set) It is always recommended that u set FRA timer higher than the DCA timer.

[Gehrig_W]

Hello Arshadsaf,

thank You very much for Your reply.

It looks like You are right and we have to wait 2 DCA cycles.

Now the entry looks like the AP has taken part of FRA-calculation showing a 76% coverage.

MIZ-AP367 08:4f:a9:ac:5a:a0 0 2.4GHz 76 None 2.4GHz

I'm using 1hour for FRA and DCA-interval of 1hour for 5GHz-Band and 10 minutes for 2,4 GHz-band.

Do You know also whether the FRA algorithm is recalculating  also for the already changed antennas to

change back from 5Ghz to 2.4GHz ?

Obviously our Coverage hole detection is not hot enough to find suddenly appearing 2,4 clients in areas where

FRA has changed the 2. antenna to 5 GHz. The shown WLAN-APs stayed on 5 GHz already for months.

Thank You very much

Wini

[Arshad Safrulla]

Do You know also whether the FRA algorithm is recalculating  also for the already changed antennas to

change back from 5Ghz to 2.4GHz ?

If you set Radio Role Assignment to manual, the this AP will be out of the FRA assignment pool, so it will not change. If Radio Role Assignment is set to Auto and FRA is enabled, so yes it is possible that the antenna you set to 2.4 will change back to 5 depending on the overlap.

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[Gehrig_W]

Hello Arshadsaf,

thank You very much for Your explanation.

Now the second question please:

Do You know also whether the FRA algorithm is recalculating  also for the already changed antennas to

change back from 5Ghz to 2.4GHz, in case of 2,4GHz-clients appearing near the AP ?

To me it seems that the antennas never change back from 5Ghz/Monitor to 2,4GHz in case 2,4GHz is needed.

Obviously our Coverage hole detection is not hot enough to find suddenly appearing 2,4 clients in areas where

FRA has changed the 2. antenna to 5 GHz. The shown WLAN-APs stayed on 5 GHz already for months.

Thank You very much

Wini