Wireless Client Drops traffic randomly while shows connected to SSID || 9800 WLC

[AnilKumar95946]

Hi Guys,

We are facing intermittent traffic drop issue when user is connected to SSID. He/She needs to disconnects and reconnect back to SSID then only it starts working again. Recently we moved from Aruba to Cisco 9800. All APs are in flexconnect mode. This site is having a very small setup having only 4 APs spread across 1 floor only.

Controller : C9800-CL Version 17.3.3

AP model C9120AXI-B 

2.4GHZ and 5 GHZ both bands are enabled on the radios. Sometimes i do fine utilization on higher side even there is no user connected specially on 2.4 ghz band. See attached screenshot for reference. 

Could you pls let me know how to troubleshoot. Let me know if you need any further info.

[Scott Fella]

First thing first.  Is it only one user or all?  Have you been able to reproduce the issue yourself?  Are the drivers on the devices all up to date and do you see any differences from device model and driver versions?  What type of security and does this happen to all types even open?

[AnilKumar95946]

Hi,

It is happening to multiple users. Happening on all device types laptops,phone etc. All trying to connect Corporate SSIDs. Haven't tried using Open authentication. Its a remote location having very few users. 

[Scott Fella]

So what your next steps should be is to see if traffic stops at the L3 interface or internet.  If the device shows connected and the controller shows connected, most likely the issue is on the infrastructure. 

You can reference the netsh on any Windows machine and see if the device shows any wifi issues or not.  Again, if not, then something in the infrastructure.  The wlan reports will show you any disconnects also.

Netsh WLAN Commands for Windows 10 - Find Wifi Key & More! (webservertalk.com)

Also explain to use what exactly is the issue?  Users saying the connection drops is very vague. Issue when roaming? issue where there is poor RSSI?