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.

Go to to verify the images.

Ensure no firewalls are blocking ports 69 (TFTP), 21 (FTP), or 22 (SSH/SFTP) between the server and the WLC. Step 3: Performing the Update (GUI Method) cisco 2500 series wireless controller firmware update

Which (e.g., 2702i, 3702e) are you managing? Do you prefer using the CLI (SSH) or the Web GUI ?

Click . You will be prompted to save your configuration—do so now. Step 5: Post-Upgrade Verification Once the controller reboots (this can take 5-10 minutes): Always read the release notes for your target version

| Issue | Likely Cause | Solution | |-------|--------------|----------| | Transfer fails | TFTP timeout | Use FTP or increase timeout ( transfer download timeout 60 ) | | APs don't join after reboot | Mismatched AP image | Set AP join mode to "global" or manually push image from WLC | | Controller boot loops | Wrong firmware (too new/old) | Console into bootloader (by breaking during boot) and load a compatible image via Xmodem or TFTP | | "Not enough flash space" | Old image still present | Delete old image via delete filename (after verifying new image boots successfully) |

To minimize downtime, use the feature found under Wireless > Access Points > Global Configuration . This allows APs to download the new firmware in the background while they are still serving clients. When you finally reboot the WLC, the APs simply swap partitions and reboot, cutting down the "dark" time from minutes to seconds. Ensure no firewalls are blocking ports 69 (TFTP),

Confirm that your existing Access Points are supported by the new firmware version. Older APs are frequently dropped in newer WLC releases.