1) Plan for a downtime window to avoid calls to the help desk that the wireless is down.
2) Prepare your controllers by backing up the configuration.
3) Make sure you have the software and FUS you need before arriving on site. If deploying remotely– plan ahead and setup a local TFTP/FTP server for file transfers and place the software on a server local to the site to avoid firewalls and slow transfer speeds.
4) If possible be ONSITE physically to monitor the device(s) Or at least have a local out of band terminal attached to console port.
5) Attach a Serial console cable NOT mini USB to the Controller prior to FUS 1.7.0.0
6) Large Sites that are High Touch Five Nines 99999.% Work in pairs to upgrade and monitor the controllers and check the configuration and test after reboot. However if this is an old hat for you then by all means do it by yourself.
7) Log your session and watch the output from the WLC Console session when upgrading the FUS code to check for anomalies since the FUS will reload a controller twice.
8) Know what you have before you start. Preform a show sysinfo at the command line or Monitor=Summary page of the controller. For controllers that do not have a FUS applied e.g. older Factory Fresh WLC’s will show Field Recover Image Version 6.0.182.0. This means that the controller most likely came from the factory with older controller software. Don’t worry this is all good.
