Network Management

AC：7210，8.6.0.5，stand

AP：535

The 2.4 radio interference of most APs is 96%, and the distance between APs is 6-8 meters. We tried to restart the radio, which returned to normal for three hours, and then the interference was severe. But it turns out that there is no problem with AP225. I modified the power, interference level and other parameters have no effect.

There is likely to be high interference on the 2.4GHz spectrum due to its nature. However are you saying that with the AP225 in the same place (i'm guessing the 535 is switched off at the same time) there is no interference whatsoever?

Also, why do you have APs so close together as this will not help and likely to cause more problems.

Are you able to provide the following outputs of the AP-535?

show ap arm history ap-name [AP NAME]
show ap arm rf-summary [AP NAME]

year，Interference is normal, but it is not normal if the interference occupies more than 90%. The attachment is a screenshot

(Aruba7210) [mynode] #show ap arm rf-summary ap-name AP-01-S

Channel Summary
---------------
channel retry phy-err mac-err noise util(Qual) cov-idx(Total) intf_idx(Total)
------- ----- ------- ------- ----- ---------- -------------- ---------------
36 13 0 20 94 26/23/2/0/99 4/0(4) 87/10//12/5(114)
40 6 0 0 92 17/12/1/0/95 4/0(4) 48/48//16/5(117)
44 0 0 2 92 55/53/1/0/92 11/0(11) 84/17//3/14(118)
48 0 0 21 92 44/42/1/0/96 0/0(0) 61/40//28/17(146)
52 0 0 14 92 50/50/0/0/91 6/1(7) 53/9//49/22(133)
56 0 0 20 92 24/22/0/0/98 0/0(0) 29/41//36/41(147)
60 0 0 54 92 38/37/0/0/93 9/1(10) 84/4//79/26(193)
64 0 0 24 92 44/43/0/0/91 0/1(1) 46/25//41/25(137)
149 0 0 32 92 43/41/1/0/93 0/0(0) 58/22//33/15(128)
153 0 0 6 92 20/18/1/0/92 10/3(13) 77/26//48/25(176)
157 0 0 38 92 32/30/1/0/87 4/0(4) 75/32//43/19(169)
161 0 0 43 92 16/14/1/0/95 0/0(0) 54/26//13/21(114)
165 0 0 10 96 20/18/1/0/97 0/0(0) 26/10//25/4(65)
1 0 0 0 46 100/0/0/0/0 0/0(0) 0/0//0/0(0)
6 0 0 0 45 100/0/0/0/0 0/0(0) 0/0//0/0(0)
11 0 0 0 96 99/0/3/0/4 0/0(0) 0/0//0/0(0)

Columns:util(Qual): ch-util/rx/tx/ext-ch-util/quality
Noise followed by "*" indicates that the last scan on this channel was a split-scan, which was
triggered by high channel noise. Check show ap arm split-scan-history.

HT/VHT Channel Summary
----------------------
Bandwidth Channel range Total interference index
--------- ------------- ------------------------
40MHz 52-56 280
40MHz 149-153 304
40MHz 36-40 231
40MHz 60-64 330
40MHz 157-161 283
40MHz 44-48 264

Interface Name :wifi0
Current ARM Assignment :36+/12.0
Covered channels a/g :12/0
Free channels a/g :0/0
ARM Edge State :disable
Last check channel/pwr :1m:11s/3m:15s
Last change channel/pwr :1h:53m:1s/1h:53m:1s
Next Check channel/pwr :4m:0s/4m:9s
Assignment Mode :Single Band

Interface Name :wifi1
Current ARM Assignment :11/9.0
Covered channels a/g :0/3
Free channels a/g :0/0
ARM Edge State :enable
Last check channel/pwr :4m:14s/0s
Last change channel/pwr :2h:44m:34s/2h:44m:34s
Next Check channel/pwr :1m:19s/4m:0s
Assignment Mode :Single Band
(Aruba7210) [mynode] #show ap arm history ap-name AP-01-S

Interface :wifi0
ARM History
-----------
Time of Change Old Channel New Channel Old Power New Power Reason Result
-------------- ----------- ----------- --------- --------- ------ ------
2020-09-17 11:28:11 36+ 36+ 9 12 P+ Configured
2020-09-17 11:20:45 36+ 36+ 12 9 P- Configured
2020-09-17 11:16:10 36+ 36+ 9 12 P+ Configured
2020-09-17 11:08:22 36+ 36+ 12 9 P- Configured
2020-09-17 10:53:36 36+ 36+ 9 12 P+ Configured
2020-09-17 10:45:55 36+ 36+ 12 9 P- Configured
2020-09-17 10:02:56 36+ 36+ 9 12 P+ Configured
2020-09-17 09:56:18 36+ 36+ 12 9 P- Configured
2020-09-17 09:47:55 36+ 36+ 9 12 P+ Configured
2020-09-17 09:41:15 36+ 36+ 12 9 P- Configured
2020-09-17 09:16:40 36+ 36+ 9 12 P+ Configured
2020-09-17 09:10:16 36+ 36+ 12 9 P- Configured
2020-09-17 08:58:02 36+ 36+ 9 12 P+ Configured
2020-09-17 08:50:39 36+ 36+ 12 9 P- Configured
2020-09-17 08:46:16 36+ 36+ 9 12 P+ Configured
2020-09-17 08:40:19 36+ 36+ 12 9 P- Configured
2020-09-17 08:35:27 36+ 36+ 9 12 P+ Configured
2020-09-17 08:28:04 36+ 36+ 12 9 P- Configured
2020-09-17 08:21:50 36+ 36+ 9 12 P+ Configured
2020-09-17 08:17:35 36+ 36+ 12 9 P- Configured
2020-09-17 07:58:12 36+ 36+ 9 12 P+ Configured
2020-09-17 07:52:52 36+ 36+ 12 9 P- Configured
2020-09-17 07:40:03 36+ 36+ 9 12 P+ Configured
2020-09-17 07:34:04 36+ 36+ 12 9 P- Configured
2020-09-17 07:21:44 36+ 36+ 9 12 P+ Configured
2020-09-17 07:15:36 36+ 36+ 12 9 P- Configured
2020-09-17 07:09:16 36+ 36+ 9 12 P+ Configured
2020-09-17 07:03:29 36+ 36+ 12 9 P- Configured
2020-09-17 06:55:52 36+ 36+ 9 12 P+ Configured
2020-09-17 06:48:48 36+ 36+ 12 9 P- Configured
2020-09-17 06:34:51 36+ 36+ 9 12 P+ Configured
2020-09-17 06:28:44 36+ 36+ 12 9 P- Configured

Interface :wifi1
ARM History
-----------
Time of Change Old Channel New Channel Old Power New Power Reason Result
-------------- ----------- ----------- --------- --------- ------ ------
2020-09-17 15:47:01 11 11 12 9 P- Configured
2020-09-17 14:52:20 11 11 9 12 P+ Configured
2020-09-17 14:52:19 11 11 9 12 P+ Not accepted
2020-09-17 11:59:45 11 11 6 9 P+ Configured
2020-09-17 11:50:45 11 11 9 6 P- Configured
2020-09-17 11:41:59 11 11 12 9 P- Configured
2020-09-17 11:23:06 11 11 6 12 P+ Configured
2020-09-17 11:12:59 11 11 9 6 P- Configured
2020-09-17 11:07:43 11 11 3 9 P+ Configured
2020-09-17 10:46:43 11 11 6 3 P- Configured
2020-09-11 23:47:21 11 11 3 6 P+ Configured
2020-09-11 16:41:37 6 11 3 3 I Configured

I: Interference, R: Radar detection, N: Noise exceeded, Q: Bad Channel Quality E: Error threshold exceeded, INV: Invalid Channel, G: Rogue AP Containment, M: Empty Channel, P+: Increase Power, P-: Decrease Power, 40INT: 40MHZ intol detected on 2.4G, NO40INT: 40MHz intol cleared on 2.4G, OFF(R): Turn off Radio due to Radar, OFF(MA): Turn off Radio due to Mode Aware, ON: Turn on Radio, Dynamic Bandwidth Switch, AIRMATCH: AirMatch Event, I*: CCA Interference, C: Radar cleared, NC: Noise Cleared, Random: Random Channel, RMC: Radio Mode Change
(Aruba7210) [mynode] #

For what reason your AP's are that close together? Basic RF design tells us to plan AP with a distance of 16-20 meter from each other. For what reason do you need 2.4GHz? If all clients support 5GHz you could disable it. 12dBm/16mW could be still to high if your AP are 6 meters apart and have a line of sight.

Did you do a WLAN Site Survey with a Spectrum Analyzer like the Ekahau Sidekick to do a properly design? Also check for non-wifi interference specially in the 2.4GHz band.

For urgent matters please call Aruba TAC support to assist you.

I agree that you should do spectrum analysis to see what the interference is. It looks like it is something non-wifi from what you shared. Could it be that you have some devices like wireless video links/extenders or so?

With such high-density APs, you probably should disable the 2.4 GHz radio on at least 50% of your APs. If you have RF-Protect licenses, you can even use the disabled 2.4GHz radios to do spectrum analysis.

If you don't have the equipment or experience to run such spectrum analysis, it may be good to get someone in. High density deployments have their own challenges: check also this VRD document.

thanks robers

I consulted tac, it is likely to be a bug, because other customers also have this problem, but there is no problem with version 8.5.0.5, so it is recommended not to use version 8.6 for 535 in the near future.

thanks,mkk

I consulted tac, it is likely to be a bug, because other customers also have this problem, but there is no problem with version 8.5.0.5, so it is recommended not to use version 8.6 for 535 in the near future.