Cisco WLC – Upgrade That Code!

I have been running on my private controller for a while. The 7.6 rev has been deferred and is no longer available – Not that you want it.

As most of you, my home network is of the utmost priority :0). I have challenging end users and making a change requires a series of change control approvals. I was finally able to secure an outage window and I am upgrading my WLC code.

This upgrade is being completed on a standalone WLC with no instances of CPI or HA involved.


office-594132_640Prepare to upgrade the software on the WLC ahead of time and please do some legwork. Review the compatibility matrix and release notes completely to ensure that the planned version of code supports all that you currently have operational. If you skip this step, update your resume.

A few reasons why – There could be an AP lingering around for years that is not supported by the planned rev of code, or maybe you are using a feature that is no longer available with the upgrade. Check that the field recovery image is at the recommended version(More about this in another post). If you are using Cisco Prime or HA, review Cisco documents to assist your upgrade approach.

There are a countless number of reasons to review the software release notes and caveats – Just do it!

Your time window will vary based on how many WLC’s and associated AP’s are part of the upgrade. Allow enough time to make the change with a cushion for mishaps.


running-498257_640Sit confidently in front of your monitor and be proud of the effort that you put forward to ensure that you have almost entirely  eliminated the possibility of that new version of code failing you.

At this point, I open up a console CLI session and the web GUI of the WLC. I like to do a brief pre-check of the state of my current wireless network.

I check the AP’s that are currently associated to the controller with the show ap summary command. This is going to be my baseline, so after the upgrade completes I am able to compare associated AP’s and ensure it is the same. I review the output from the show sysinfo command and I like to review the monitor tab on the GUI as well. Take a few screenshots, log your CLI sessions or copy/paste the output.

I also start a continuous ping to the WLC at this point. This is a handy resource for the rest of the upgrade.

Navigating to the COMMANDS tab on the WLC will open up the download tool on the WLC. This download/upload on the WLC is a bit confusing for some, but it easy to remember. Always think of the WLC as the host machine and you will either download to the WLC or upload from the WLC – Since I am upgrading code, I will download to the WLC.

Notice the drop down with the 3 transfer mode options. Also, note that you will need to add the file name on this page and the address of your TFTP server. I am using TFTP and the Solarwinds TFTP server for this example.


After you have chosen a transfer mode, set the ip address of your TFTP server and set a file name, you are ready to begin the download.

On the same page, navigate to the upper right corner and select the [Download] box. This will initiate the download process to the WLC. If you bump in to an issue here, make sure you do not have firewall restrictions or TFTP server configuration mistakes.

If all is configured correctly the download will start and a series of messages will appear on the same page of the WLC. The download could take a few minutes, so kick back and relax.


When the download is complete the message will let you know…


Slow down there partner… We will not be reloading for a few minutes. Let’s pre-download the new code to the associated access points to reduce downtime after the reload.

Navigate to the WIRELESS tab and then select Global Configuration from the left side column. Scroll to the bottom of this page and select [Download Primary].


After choosing to pre-download the image, select All AP’s from the left column and review the download status. Use the refresh icon on the upper right side of the page to update the status.


The status will change to Complete and the Backup SW version will now reflect the new rev.




The time has come – Time to reload the WLC. Remember that ping I had you start earlier? Bring that screen up.

Navigate to the COMMANDS tab again and select Config Boot from the left column. You face 2 choices under the Config Boot Image drop down- Primary or Backup. Select your image and then hit [APPLY] in the upper left.

Are you ready? Have you taken all of the necessary steps to make this as seamless to your end users as possible? Are you a network ninja?

OK – Then let’s do it!

Select Reboot from the left column under the COMMANDS tab. You are greeted with a nice warning message. When you are ready, hit the [Save and Reboot] button in the upper right corner.


Keep an eye on the steady ping to the WLC and wait for it to come back online.

Once the system is back up, I like to review the config. I also ensure the same number of AP’s are associated – Exactly like the baseline I had before the reboot. I also verify that clients are associating to AP’s.

If everything checks out and your phone is not ringing, you have completed this upgrade and the majority of people had no idea that awesome, late night sacrifice you made to improve their experience.

I look forward to your thoughts.

Let me have it!

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