Your Access Points will detect the new version, download it from the WLC, and reboot themselves. This is the period of highest "down time" for wireless clients.
Updating the firmware on a Cisco 2500 Series Wireless Controller (WLC) is a critical maintenance task that ensures network security, stability, and compatibility with newer Access Point (AP) models. This guide provides a comprehensive walkthrough for administrators looking to navigate the upgrade process safely. Pre-Upgrade Checklist cisco 2500 series wireless controller firmware update
Always read the release notes for your target version. Check for "Deferred" releases or specific bugs that might affect your environment. Your Access Points will detect the new version,
The Web Interface is the most user-friendly way to handle the update. Log in to the WLC GUI. Go to the tab at the top. On the left sidebar, select Download Software . Select the File Type (Code). Choose your Transfer Mode (TFTP, FTP, or SFTP). Enter the IP Address of your server and the File Path/Name . Click Download . The Web Interface is the most user-friendly way
Once the download is complete, the new version sits in the slot.