Delayed roaming

[Pako1]

I have inherited a 5 year old WLAN deployment where clients have never successfully roamed. There is a 10 - 20 second delay when moving between AP. During this break the wifi icon disappears from devices and connectivity is lost. We have a mix of iOS, Android, SurfacePro and the odd laptop on the network and all encounter the same issue. I do not see any disassociation events in the debug when this happens.

Where do I troubleshoot from here to track down the root cause? have attached a debug log

5508 (8.2.151.0) controller and mix of 3502 & 3602 AP. Dual 2.4/5Ghz

[MauroSergioPatriota3851]

Hello,

Did you find the issue?

I am having the same problem with intel 8265ac and there is no evidence on WLC about what is happening.

It seems that the client stick on the AP and when the radio reset or the client roam he falls and does not come back.

[jonathga]

Hello Mauro, Do you mean that the wireless client is connected to one AP and when it tries to roam to another AP it cannot connect to the wireless network anymore?

[MauroSergioPatriota3851]

Exactly!
The Wifi client just stop to responding on network and there no info on WLC.

[jonathga]

Hello Mauro, try to identify if the issue is on the client-side or the AP side.

From the WLC we should be able to see the new reassociation request from the client to the new AP, the authentication (PSK or 802.1x) and the 4-way handshake. to get that information run a debug on the WLC to track one client and wait until the issue happens again so we should be able to see if the WLC is receiving all that information. Follow the steps in the guide below to accomplish that task:

https://www.cisco.com/c/en/us/support/docs/wireless/wireless-lan-controller-software/213258-collect-debugs-from-wireless-lan-control.html

Once the desired event has occurred and you were able to debug it, you need to read the logs. You can use the guides in the links below to know how to read the debugs:

https://www.cisco.com/c/en/us/support/docs/wireless/aironet-1200-series/100260-wlc-debug-client.html
https://mrncciew.com/2014/10/15/wlc-client-debug-part-1/
https://mrncciew.com/2014/10/17/wlc-client-debug-part-2/
https://mrncciew.com/2019/06/03/wlc-client-debug-part-3/

Or you can use the online debug reader with a Cisco ID at https://cway.cisco.com/tools/WirelessDebugAnalyzer/ 

From the client you should be able to see the client looking for another AP when the signal is weak, a new connection request for the new AP, the authentication and the 4-way handshake, you can look at that by running tracest on the laptop. Take a look at the video in the link below, start watching the video from minute 22:00 for checking how to run tracest and how to read them:

https://www.youtube.com/watch?v=vYbtiY3bnTM&t=640s

before doing all the stuff above make sure that your WLC is running a recommended code listed in this link: https://www.cisco.com/c/en/us/support/docs/wireless/wireless-lan-controller-software/200046-tac-recommended-aireos.html

And that your wireless client is running the latest wireless driver code. Look for that information on the CMD using netsh WLAN show driver command, look at this link as a reference of what you should see: https://www.solvetic.com/tutoriales/article/4168-comando-netsh-gestionar-conexion-red-wifi-windows/ finally look at the driver provider web page whats the latest code for your NIC.