Hive Ap120 5Ghz band dropping frequently. 6.5r3

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  • Updated 2 years ago
Hive AP 120 5Ghz client seizing up every so often... Log shows background scan happening before/during each occurrence. 

2016-02-14 12:04:13 info    ah_cli: admin:<show log buffered >
2016-02-14 12:04:03 info    kernel: [wifi]: wifi1: background scan done, num_bgscans 368, num_req_bgscans 383
2016-02-14 12:03:58 info    kernel: [wifi]: wifi1: trigger background scan: chans scanned 221, cont periodic scan 
2016-02-14 12:01:51 debug   kernel: skip bg-scan on dev(wifi0)
2016-02-14 12:01:51 debug   kernel: Skip bg-scan since power-save client associated


Sometimes it's just a one second drop, other times it drops for several minutes. 

Any idea what could be going on?

APs not running on the Hive, simple config:


AH-19bd40#show running-config 
security-object Tumbeldber
security-object Tumbeldber security protocol-suite wpa2-aes-psk ascii-key *** 
ssid Tumbeldber
ssid Tumbeldber security-object Tumbeldber
hive Hive-1
hive Hive-1 password ***
interface eth0 native-vlan 1
interface wifi0 radio channel 11
interface wifi1 mode access
interface wifi1 radio channel 165
interface mgt0 hive Hive-1
interface wifi0 ssid Tumbeldber
interface wifi1 ssid Tumbeldber
system led brightness dim
admin root-admin admin password *** 
dns server-ip 208.67.222.222 
dns server-ip 208.67.220.220 second
ntp server 0.aerohive.pool.ntp.org 
ntp server 1.aerohive.pool.ntp.org second 
ntp server 2.aerohive.pool.ntp.org third 
ntp server 3.aerohive.pool.ntp.org fourth 
clock time-zone -5 
clock time-zone daylight-saving-time 03-13 01:59:59 11-06 01:59:59
no capwap client enable
no bonjour-gateway enable


is this something to do with power saving? can it effectively be disabled?

Any help appreciated.. first time tinkering with Hive AP's.

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Casey Doyle

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Posted 2 years ago

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Photo of Nick Lowe

Nick Lowe, Official Rep

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Hi Casey,

When a full background scan takes place, the radio it is taking place on goes off the channel serving clients in order to perform it. (This is known as time slicing.)

As client devices cannot be served by a radio while this takes place, the approach can degrade performance. Furthermore, as client densities go up, so does the level of performance degradation observed.

Can you elaborate on what you mean by 'seizing up' therefore? Clarity would be helpful specifically on... Does the client, without undue and unexpected interruption, retain and regain access once the scan has completed?

Within HiveManager, you can disable or change the nature of background scans in a radio profile:


If you need continuous service, you must ensure that background scanning is disabled when there are clients connected. This is not the default behaviour and there are always inherent tradeoffs (where there are not dedicated radios for scanning). The tradeoffs must be balanced based on the needs of an environment.

Hope this helps,

Nick

(Edited)
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Casey Doyle

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Awesome,


so i meant, the wireless stays connected, but can't ping anything while the scan is in progress.... once scan is complete, wifi is able to talk again.


so, as per your suggestion, i enabled Radio profile for the devices, and disabled background scanning for both bands...

For now, let's see how it goes.. so far so good.

Here is the config as it stands now


AH-221f00#show running-config 
radio profile radio_ng0_good
radio profile radio_ng0_good phymode 11ng
radio profile radio_ng0_good acsp all-channels-model enable
no radio profile radio_ng0_good scan access
radio profile radio_na0_good
radio profile radio_na0_good phymode 11na
no radio profile radio_na0_good scan access
security-object Tumbeldber
security-object Tumbeldber security protocol-suite wpa2-aes-psk ascii-key *** 
ssid Tumbeldber
ssid Tumbeldber security-object Tumbeldber
hive Hive-1
hive Hive-1 password ***
interface eth0 native-vlan 1
interface wifi0 radio profile radio_ng0_good
interface wifi0 radio channel 11
interface wifi1 radio profile radio_na0_good
interface wifi1 mode access
interface wifi1 radio channel 165
interface mgt0 hive Hive-1
interface wifi0 ssid Tumbeldber
interface wifi1 ssid Tumbeldber
system led brightness dim
admin root-admin admin password *** 
dns server-ip 208.67.222.222 
dns server-ip 208.67.220.220 second
ntp server 0.aerohive.pool.ntp.org 
ntp server 1.aerohive.pool.ntp.org second 
ntp server 2.aerohive.pool.ntp.org third 
ntp server 3.aerohive.pool.ntp.org fourth 
clock time-zone -5 
clock time-zone daylight-saving-time 03-13 01:59:59 11-06 01:59:59
no capwap client enable
no bonjour-gateway enable
AH-221f00#


my next question would be, will the background scanning kill the Hive in any way? can the hive communicate through eth0?


Thank you for the advice!!
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Nick Lowe, Official Rep

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The periodic background scan is used for things like rogue device / policy violation detection. It is not a crucial to have it enabled therefore. In many environments, it is worthwhile disabling it.