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Re: Regular complaints of getting disconnected coming in from students

Hey there, 

 

So we have come accross similar issues here at liberty and wanted to see if anybody else is seeing this. We first reviewed our 802.1x (AAA) timers, idle timeout, Station ageout and updated our client match band steering thresholds. After further investigation we took three clients with the disconnect issue and monitored over a 24 period. During this time i found multiple channel changes were occuring. 

 

AoS 6.3.1.13

HA 7220 Masters and 4 local 7220s the 4th being N+1.

Issue has been occuring since semister startup.

We use 4 20k CPPM physical nodes behind an F5 for Radius Auth Airgroup, Guest, etc.

 

When running the show ap arm history command we saw a lot of channel changes with the reason "E: Error threshold exceeded". 

 

Interface :wifi0
ARM History
-----------
Time of Change Old Channel New Channel Old Power New Power Reason
-------------- ----------- ----------- --------- --------- ------
2014-11-06 14:48:09 149+ 149+ 21 24 P+
2014-11-06 14:42:04 149+ 149+ 18 21 P+
2014-11-06 10:51:53 149+ 149+ 24 18 P-
2014-11-06 02:00:13 161- 149+ 24 24 E
2014-11-05 19:40:10 153- 161- 24 24 E
2014-11-05 19:39:08 157+ 153- 24 24 E
2014-11-05 19:29:38 153- 157+ 24 24 E
2014-11-05 19:14:06 153- 153- 21 24 P+
2014-11-05 18:42:08 153- 153- 18 21 P+
2014-11-05 14:59:19 40- 153- 18 18 E
2014-11-05 14:58:13 40- 40- 24 18 P-
2014-11-05 14:51:44 157+ 40- 24 24 E
2014-11-05 13:12:03 157+ 157+ 21 24 P+
2014-11-05 12:49:47 157+ 157+ 18 21 P+
2014-11-05 12:36:43 157+ 157+ 24 18 P-
2014-11-05 11:47:33 40- 157+ 24 24 E
2014-11-05 10:06:35 40- 40- 21 24 P+
2014-11-05 10:02:18 40- 40- 18 21 P+
2014-11-05 09:50:39 40- 40- 24 18 P-
Interface :wifi1
ARM History
-----------
Time of Change Old Channel New Channel Old Power New Power Reason
-------------- ----------- ----------- --------- --------- ------
2014-11-05 06:43:09 11 11 15 12 P-
2014-11-05 06:38:51 11 11 12 15 P+
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: Turn off Radio, ON: Turn on Radio

(JFL-local-01) #show ap association ap-name RCH01-A827-AP135

The phy column shows client's operational capabilities for current association

Flags: A: Active, B: Band Steerable, H: Hotspot(802.11u) client, K: 802.11K client, R: 802.11R client, W: WMM client, w: 802.11w client

PHY Details: HT : High throughput; 20: 20MHz; 40: 40MHz
VHT : Very High throughput; 80: 80MHz; 160: 160MHz; 80p80: 80MHz + 80MHz
<n>ss: <n> spatial streams

 

Association Table
-----------------
Name bssid mac auth assoc aid l-int essid vlan-id tunnel-id phy assoc. time num assoc Flags Band steer moves (T/S)
---- ----- --- ---- ----- --- ----- ----- ------- --------- --- ----------- --------- ----- ----------------------
RCH01-A827-AP135 24:de:c6:0c:4c:91 7c:7a:91:cd:de:21 y y 1 250 Liberty-Secure 3801 0x104af a-HT-40sgi-2ss 2h:54m:52s 1 WAB 0/0
RCH01-A827-AP135 24:de:c6:0c:4c:82 50:1a:c5:c0:f3:0d y y 1 10 Liberty-Wireless 3920 0x104b4 g-HT-20-2ss 21h:29m:43s 1 WAB 0/0
RCH01-A827-AP135 24:de:c6:0c:4c:91 60:03:08:8f:05:5c y y 3 10 Liberty-Secure 3825 0x104af a-HT-40sgi-3ss 42m:59s 1 WAB 0/0
Num Clients:3
Total num of 5G capable clients:3
Total num of 5G capable clients in 2.4G band:1
Total num of 5G capable clients in 5G band:2
Total num of 2.4G only clients:0

 

When conducting a client trail we found the following:

 

Client Trail Info
-----------------
MAC BSSID ESSID AP-name VLAN Deauth Reason Alert
--- ----- ----- ------- ---- ------------- -----
50:1a:c5:c0:f3:0d 24:de:c6:0c:4c:82 Liberty-Wireless RCH01-A827-AP135 3920 Unspecified Failure Unspecified Failure

Deauth Reason
-------------
Reason Timestamp
------ ---------
Unspecified Failure Nov 5 19:39:07
Unspecified Failure Nov 5 19:29:37
Unspecified Failure Nov 5 14:59:19
Unspecified Failure Nov 5 14:51:43
Unspecified Failure Nov 5 11:47:32
STA has left and is deauthenticated Nov 5 11:34:02
STA has left and is deauthenticated Nov 5 11:33:08
STA has left and is deauthenticated Nov 5 11:30:33
Num Deauths:8

Alerts
------
Reason Timestamp
------ ---------
Unspecified Failure Nov 5 19:39:07
Unspecified Failure Nov 5 19:29:37
Unspecified Failure Nov 5 14:59:19
Unspecified Failure Nov 5 14:51:43
Unspecified Failure Nov 5 11:47:32
STA has left and is deauthenticated Nov 5 11:34:02
STA has left and is deauthenticated Nov 5 11:33:08
STA has left and is deauthenticated Nov 5 11:30:33
Num Alerts:8

Mobility Trail
--------------
BSSID ESSID AP-name Timestamp
----- ----- ------- ---------
24:de:c6:0c:4c:82 Liberty-Wireless RCH01-A827-AP135 Nov 5 19:39:10
24:de:c6:0c:4c:92 Liberty-Wireless RCH01-A827-AP135 Nov 5 19:39:07
24:de:c6:0c:4c:92 Liberty-Wireless RCH01-A827-AP135 Nov 5 19:29:41
24:de:c6:0c:4c:92 Liberty-Wireless RCH01-A827-AP135 Nov 5 19:29:37
24:de:c6:0c:4c:92 Liberty-Wireless RCH01-A827-AP135 Nov 5 14:59:24
24:de:c6:0c:4c:92 Liberty-Wireless RCH01-A827-AP135 Nov 5 14:59:19
24:de:c6:0c:4c:92 Liberty-Wireless RCH01-A827-AP135 Nov 5 14:51:48
24:de:c6:0c:4c:92 Liberty-Wireless RCH01-A827-AP135 Nov 5 14:51:43
24:de:c6:0c:4c:92 Liberty-Wireless RCH01-A827-AP135 Nov 5 13:29:07
24:de:c6:0c:4c:92 Liberty-Wireless RCH01-A827-AP135 Nov 5 11:47:32
Num Mobility Trails:10

 

In most clients when we see "Unspecified Failure" it matches up with the channel changes that reside with the threshold errors. Currently we have a known issue with our internet pipes being over subscibed and are in the process of upgrading to 10gb uplings. I think some of what were is airtime being crowded due retrys however when we look at the controller the channels look healthy for this ap on the 5ghz.

 

Airwave RF capacity statisics below for the follow A radio. The WAP is an AP135 that averages 8 clinets per radio. 

 

 Last Min Max Avg 

 
Busy
16.93 %1.57 %33.46 %11.42 %
 
Interference
1.57 %0 %24.41 %1 %
 
Receiving
9.84 %0.79 %30.71 %8.27 %
 
Transmitting
6.69 %0 %16.93 %2.76 %

 

 

AoS 6.3.1.13

HA 7220 Masters and 4 local 7220s the 4th being N+1.

Issue has been occuring since semister startup.

We use 4 20k CPPM physical nodes behind an F5 for Radius Auth Airgroup, Guest, etc.

T.J. Norton - Wireless Architect

All opinions written here are my own and do not necessarily reflect the views and opinions of my employer or Aruba Networks