Excessive roaming in WLAN


Hi,
we have a WLAN with over 100 APs (37xx adn 38xx) in 3 Locations. V2110 as controllers with version 9.21.13.00005.
Recently we recognize some strange syslog entries regarding roaming behaviour:
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp028] FromAP[apgcp053] BSSID[D8:84:66:69:AD:C8] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp028] FromAP[apgcp053] BSSID[D8:84:66:69:AD:C8] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp028] FromAP[apgcp053] BSSID[D8:84:66:69:AD:C8] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp028] FromAP[apgcp053] BSSID[D8:84:66:69:AD:C8] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp028] FromAP[apgcp053] BSSID[D8:84:66:69:AD:C8] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:49 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:49 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp028] FromAP[apgcp053] BSSID[D8:84:66:69:AD:C8] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:49 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:49 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp028] FromAP[apgcp053] BSSID[D8:84:66:69:AD:C8] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:49 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:49 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp028] FromAP[apgcp053] BSSID[D8:84:66:69:AD:C8] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:49 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
[/code]This repeats als 15 seconds. All affected MACs are from Vendor 34:14:5F (Samsung electronics) and it only happens between a handful of our 122 APs. I dont know if this goes along with new devices or with the change of 36xx APs to 38xx.

Does anyone have seen this before or can explan it?

Thanks, Bernhard

6 replies

Userlevel 4
Can you confirm how SSID1 is configured, is it 802.1x and 802.11r enabled?

We have discovered and reported to Samsung a bug with Samsung S7 802.1x stack for Verizon, but the same bug may have made it out to other carriers. Samsung is working on a fix but no certain when it will make it out to their network customers.

As a workaround for now, disable 11r on the SSID , 'forget' the network on the devices (to remove their cache of 11r capability on the service) and try re-associating again.
Paulo Francisco wrote:

Can you confirm how SSID1 is configured, is it 802.1x and 802.11r enabled?

We have discovered and reported to Samsung a bug with Samsung S7 802.1x stack for Verizon, but the same bug may have made it out to other carriers. Samsung is working on a fix but no certain when it will make it out to their network customers.

As a workaround for now, disable 11r on the SSID , 'forget' the network on the devices (to remove their cache of 11r capability on the service) and try re-associating again.

the conspicuous roaming only occures in a VNS which has only privacy WPA v.2 enabled, but no Authorization. So disabling 802.11r is no option.
Userlevel 2
I had some serious roaming issues with CAC (call admission control) activated with Spectralink devices - turning that feature off (WLAN Services-Qos-Global Admission Control) helped.

Perhaps that helps so far
Peter Kulmbrein wrote:

I had some serious roaming issues with CAC (call admission control) activated with Spectralink devices - turning that feature off (WLAN Services-Qos-Global Admission Control) helped.

Perhaps that helps so far

Global Admission Control is not enabled on this VNS. Just WMM.
Userlevel 1
Hello,
Do you know if load group "client balance" is configured? We can better understand this behavior if your able to provide more details about the VNS configuration and AP radio settings.
A strong case can be made for increasing "Min basic rate" setting on the radios. This will help with maintaining client/radio associations. Of course this is assuming RF coverage and overlaps aren't an issue. If these recommendations do not work out, please give GTAC a call for further assistance with this issue.

Thank you.

Bill McIver
Global Technical Assistance Center
Extreme Networks
Bill McIver wrote:

Hello,
Do you know if load group "client balance" is configured? We can better understand this behavior if your able to provide more details about the VNS configuration and AP radio settings.
A strong case can be made for increasing "Min basic rate" setting on the radios. This will help with maintaining client/radio associations. Of course this is assuming RF coverage and overlaps aren't an issue. If these recommendations do not work out, please give GTAC a call for further assistance with this issue.

Thank you.

Bill McIver
Global Technical Assistance Center
Extreme Networks

We are not using Load Groups until now.
This behavor with rapidly roaming between APs only occoures in 2 of our VNS, which are both simple WPA-PSK with no Authentication. Both use the same topoligy (bridged at EWG).
I also configured "min basic rate" to 5.5 Mbps, Probe Suppression and Force Disassociate enabled and RSS Threshold to -75

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