Solved: The updates you are trying to apply are not Dell-authorized updates

When I booted into System Services using F10 on a Dell PowerEdge T710 to run the Platform Update on the LifeCycle Controller (translation: the firmware connects to Dell's FTP site and downloads and installs firmware updates for you) I saw "The updates you are trying to apply are not Dell-authorized updates."

After the initial wry smile about Dell firmware connecting to a Dell site to download Dell drivers and then failing and calling them "not Dell-authorized," I proceeded to do the following:

Update LifeCycle Controller

I connected to iDRAC6 and used the firmware update option to give it this file (I used Firefox to access iDRAC because of reports of the update hanging when using Internet Explorer):

ftp://ftp.dell.com/Browse_For_Drivers/Servers%2C%20Storage%20%26%20Networking/PowerEdge/PowerEdge%20T710/Lifecycle%20Controller/Application/OS%20Independent/2012-05-21%20-%20BDF_1.5.2_BIN-7.usc

Update iDRAC

Then I fed the same iDRAC6 firmware update option the firmimg.d6 file gotten from running the following on Windows:

http://downloads.dell.com/FOLDER00807902M/1/iDRAC6_1.92_A00_FW_IMG.exe

Linux Support

The above worked after I naively thought I could use the Linux files from Dell. Dell helpfully provides a Linux .BIN file that you can download and run, if you run 32-bit or have 32-bit compatibility libraries installed:

No, Dell, all my stuff is 64-bit. For many years now.

It's 2013. Why are firmware updates still such a nightmare, Dell?

P.S. The Broadcom network firmware still can't be updated via the LifeCycle Controller method. This has been broken for at least a year.

Reference:

[FYI] [FIX] The updates you are trying to apply are not Dell-authorized updates
The updates you are trying to apply are not Dell-authorized updates