Cisco 9800 Wireless 2025 – High Availability Upgrade to 17.12.04

The Cisco Catalyst 9800 wireless controller can be upgraded using a variety of methods, including:

Software Maintenance Upgrade (SMU): Installs a software package to fix bugs or provide security updates
Hitless Upgrade: Upgrades APs in stages while they remain connected to the controller.
Software Maintenance Upgrade (SMU): This method is used to fix bugs or provide security updates.
Hitless Upgrade: This method allows APs to be upgraded in stages while they remain connected to the controller.
In-Service Software Upgrade (ISSU): Upgrades a wireless controller image to a newer release while the network continues to function.This method is ideal for 24/7 environments because it minimizes downtime. It can also be used to apply cold patches without impacting the active network.

0. Clean up the “inactive” files from the 9800

1. Verify the that the devices are in HA/SSO mode

2. Copy the desired software from the remote file server to the 9800

Copy the new image to flash

9800#copy scp:C9800-CL-universalk9.17.15.03.SPA.bin flash:
Address or name of remote host [10.0.0.4]? 
Source username [lab]? 
Source filename [C9800-CL-universalk9.17.12.02.SPA.bin]? 
Destination filename [C9800-CL-universalk9.17.12.02.SPA.bin]? 
Password:

3. Verify that the file was copied.

dir flash:*.bin

4. Select the file to be installed on the SSO pair

CLI verification

5. The secondary device will reboot and reinitialize HA

The primary WLC will be upgraded next

Log file

install_add: START Mon Aug  4 08:54:55 est 2025
install_add: Adding PACKAGE
install_add: Checking whether new add is allowed ....

--- Starting initial file syncing ---
[1]: Copying bootflash:C9800-CL-universalk9.17.15.03.SPA.bin from chassis 1/R0 to chassis 2/R0
[2]: Finished copying to chassis 2/R0  
Info: Finished copying bootflash:/C9800-CL-universalk9.17.15.03.SPA.bin to the selected chassis
Finished initial file syncing

--- Starting Add ---
Performing Add on all members
  [1] Add package(s) on chassis 1/R0
  [1] Finished Add on chassis 1/R0
  [2] Add package(s) on chassis 2/R0
  [2] Finished Add on chassis 2/R0
Checking status of Add on [1/R0 2/R0]
Add: Passed on [1/R0 2/R0]
Finished Add

Image added. Version: 17.15.03.0.5635
SUCCESS: install_add  Mon Aug  4 09:00:35 est 2025

Starting AP Image Predownload..
AP Image Predownload started successfully.
AP Image Predownload Status:
Total number of APs  : 1

Number of APs 

        Initiated                  : 0

        Downloading                : 0

        Predownloading             : 0

        Completed downloading      : 0

        Completed predownloading   : 3

        Not Supported              : 0

        Failed to Predownload      : 0

        Predownload in progress    : No

AP Name                           Primary Image          Backup Image            Predownload Status   Predownload Version  Next Retry Time   Retry Count   Method

------------------------------------------------------------------------------------------------------------------------------------------------------------------

LAP_LA_3800                       17.12.5.202            17.15.3.28                 Complete              17.15.3.28            0                 0                 CAPWAP

Starting ISSU Install Activate Operation...
install_activate: START Mon Aug  4 09:02:29 est 2025
install_activate: Activating ISSU

NOTE: Going to start Activate ISSU install process

STAGE 0: System Level Sanity Check
===================================================
--- Verifying install_issu supported ---
--- Verifying standby is in Standby Hot state ---
--- Verifying booted from the valid media ---
--- Verifying AutoBoot mode is enabled ---
--- Verifying Platform specific ISSU admission criteria ---
--- Verifying Image ISSU Compatibility ---
Finished Initial System Level Sanity Check


STAGE 1: Installing software on Standby
===================================================
--- Starting install_remote ---
[2] install_remote package(s) on chassis 2/R0
WARNING: Found 1660 disjoint TDL objects.

[2] Finished install_remote on chassis 2/R0
install_remote: Passed on [2/R0]
Finished install_remote


STAGE 2: Restarting Standby
===================================================
--- Starting standby reload ---
Finished standby reload

--- Starting wait for Standby to reach terminal redundancy state ---
Finished wait for Standby to reach terminal redundancy state


STAGE 3: Installing software on Active
===================================================
--- Starting install_active ---

Note:

During the upgrade you’ll be kicked out of the active device