Chronic connection drop issues in a Cisco environment

[Mr Z]

Hi everyone,

In a Cisco environment, we are experiencing chronic network drop issues. We are using the C9800 controller (software version 17.09.03) and APs of the model C9120AXI-Z (software version 17.9.3.203). We are utilizing a 5GHz CA network, and the connection is extremely unstable, dropping multiple times throughout the day. The complexity is that it is unstable for some people and not for others, across different laptop models. Has anyone encountered similar cases?

[Joseph W. Doherty]

I have no experience that specifically matches yours, although there's so many possible issues that can cause wireless issues.

However, I'm really making this reply, because I might suggest, the forums for "Wireless - Mobility" might be a better choice than this forum.

[Leo Laohoo]

Post the complete output of the following commands into a text file and attach the text file: 

sh ap dot11 5 cleanair device
sh ap auto-rf dot 5
sh ap summary load-info
sh ap uptime
sh platform resources
sh platform software mount | include tmpfs.*tmp

[Mr Z]

Hi everyone,

In a Cisco environment, we are experiencing chronic network drop issues. We are using the C9800 controller (software version 17.09.03) and APs of the model C9120AXI-Z (software version 17.9.3.203). We are utilizing a 5GHz CA network, and the connection is extremely unstable, dropping multiple times throughout the day. The complexity is that it is unstable for some people and not for others, across different laptop models(Dell and HP). Has anyone encountered similar cases? Also, what tools can I use to diagnose these network issues?

[marce1000]

   - Has there been a wireless site survey to have optimal and correct placement of access points ?

   M.

[Rich R]

1. Your software is out of date - see the TAC recommended link below and upgrade to eliminate many known, fixed bugs.  Make sure to read the Release Notes first because there may be new issues in the updated software.  Also take note of field notices and technotes below.

2. Make sure all laptop OS and drivers are up to date - in particular Intel drivers:
https://www.intel.com/content/www/us/en/download/19351/intel-wireless-wi-fi-drivers-for-windows-10-and-windows-11.html

3. Check your WLC config with the Config Analyzer - see the link below.  This will highlight many common mistakes and best practices.  And read the Best Practices guide (link below)

4. Debugging and troubleshooting:
https://www.cisco.com/c/en/us/support/wireless/catalyst-9800-series-wireless-controllers/products-tech-notes-list.html
https://logadvisor.cisco.com/logadvisor/wireless/9800/