Changes in Policy Tag and impact to connected clients?

[Charlie Grey]

hi,

current production running a pair of C9800 in HA w 200x connected AP.

If i make changes to the existing Policy Tag that is in use; 

example - add a >new< WLAN + Policy profile or

example - Change existing WLAN profile authentication protocol use.

what is the impact to connected clients? will they face a temp d/c from wifi?

or it will be transparent to all wifi clients becos the new wlan + profile profile no one is connecting to and the change to authention protocol no issue unless some clients are re-authenticating at that moment??

thanks for reading.

[balaji.bandi]

If you creating new WLAN and profile i do not see any effect on the exiting clients.

some of the changes does not required AP to reboot. (that means clients connect will not effect) - until document mentioned AP reboot required.

https://www.cisco.com/c/en/us/support/docs/wireless/catalyst-9800-series-wireless-controllers/213911-understand-catalyst-9800-wireless-contro.html#toc-hId-1358950533

https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/17-9/config-guide/b_wl_17_9_cg/m_config_model.html?bookSearch=true#controller-config-model

[Mark Elsen]

  - FYI : https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/17-3/config-guide/b_wl_17_3_cg/m_client_roaming_policy_profile.html

 M.

[Rich R · Accepted solution]

Generally speaking adding/removing/updating a WLAN will not affect clients on other WLANs but some features may cause a reset of the radio which will affect all clients on all WLANs.  Also you have to consider unexpected bugs which might cause impact such as https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwh61011 which can cause instability and failure of the whole AP after simply making a small change to WLAN (we have seen this one). So:
1. Ideally test your changes in a lab environment first
2. Make sure your software is up to date (refer to TAC recommended link below)
3. Plan your changes for "Out of working hours" (if possible, otherwise during approved maintenance window) to be safe and always do pre and post change checks to ensure no impact.  Get a user to test to confirm everything still working as expected.  If something goes wrong be prepared for what you might need to do to resolve the issue.  For example reload the AP if you encounter CSCwh61011.