Bootloader Version................... 1.0.20
: Log into the WLC CLI and run the command show sysinfo . Check the Bootloader Version and Field Upgrade Software Version. If it is already at 2.0.0.0, this upgrade is unnecessary. air-ct2500-k9-2-0-0-0-fus.aes
Field Upgrade Software (FUS) is a special AES-encrypted software package used specifically for Cisco Wireless LAN Controllers (WLCs). It is a critical maintenance tool, separate from the main AireOS operating system that runs your wireless network. Bootloader Version
To use the file, you typically need the installation guide. air-ct2500-k9-2-0-0-0-fus.aes
Installation of a FUS image takes significantly longer than a standard software update (often 30+ minutes). The controller will reboot multiple times during this process; do not power off
Let's break down the filename air-ct2500-k9-2-0-0-0-fus.aes :