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New Member

Upgrading Controller and Config Files


I am upgrading my 4402 controller from to 4.2.130. It says I need to save my current config because it will get dumped when I do the upgrade. What extension type do I save the config files as? It does not state this anywhere...

Cisco sure doesn't make this process very easy. Save config file. Upgrade code. Download saved config file to controller. Hope nothing gets corrupted with all that and hope everything is re-enabled and configured like it was before upgrade? Seems like a lot can go wrong...


Re: Upgrading Controller and Config Files

From a proprietary format, Cisco went to XML in 4.2. This means that your config cannot be transfered from a 4.1 controller to a 4.2 controller.

Of course if you have a config, it will be upgraded with the code, saving is just a precaution.



New Member

Re: Upgrading Controller and Config Files


I understand that. The documentation from Cisco says I have to save my config while my controller is still using 4.1.170. Then upgrade to 4.2.130. It said to back the config up before doing so as I will lose the current config. My question is what do I save the 4.1 config file as .txt, .xml, .make something up??? I'm presuming that once I upload that saved config back to the controller it will convert it to the newer 4.2 .xml format. Am I correct in assuming that?

New Member

Re: Upgrading Controller and Config Files


This is from the release notes:

In controller software 4.2, the controller's bootup configuration file is stored in an Extensible Markup

Language (XML) format rather than in binary format. Therefore, you cannot download a binary

configuration file onto a controller running software release 4.2. However, when you upgrade a

controller from a previous software release to 4.2, the configuration file is migrated and converted to


This conflicts with what Cisco states earlier in their documentation. I thought when you upgrade it wipes everything and you loser your current config? After reading this section I gather that I only lose the running config and that it will upgrade the config stored in NVRAM? That all makes a lot more sense than what they say earlier in the guide. Once I do the upgrade I can't impor the old config due to it being in the wrong format.

So in closing this mess my take is that I just need to upload the new software image to the controller. It will load the new software version and then convert the existing config in NVRAM into the new .xml format? Yes?

Hall of Fame Super Silver

Re: Upgrading Controller and Config Files

In short, you will be fine upgrading, but when you downgrade, you will loose everything. I have just tested it with a wlc running 3 code and upgrading it to 4.2.130. Kept the configuration.

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Re: Upgrading Controller and Config Files


To be clearer:

- You have a controller with 4.1 code, you save your config as a safety, it's a binary file, name it the way you want (I use .cfg, but there is no boligation, the file extension will not determine the file format, it will be proprietary binary format anyway).

- You upgrade the config to 4.2. The config onboard the controller is maintained.

- You suddenly change your mind and want to downgrade to 4.1 (not using the 4.1 backup image still present in your controller, but by downloading a new 4.1 image). Your config is wipped but you can reimport the config you wisely saved before moving to 4.2.

Does that make more sense?