Cannot update from firmware 2.2.0 on Devolo dLAN 1200+ WiFi ac PowerLine Adapter

This article discusses how to update the firmware on a Devolo dLAN 1200+ WiFi ac PowerLine adapter with firmware version less than 5.3.4.

More Info

I had a client with a number of Devolo dLAN 1200+ PowerLine adapters, however, for whatever reason the firmware had been stuck on version 2.2.0 (2018-07-26) and had never migrated forward to a newer version.

Attempting to use the web interface to update the firmware resulted in an error and a timeout – presumably because the repository URL had changed since 2018.

The advice indicated on the website was to install Devlolo Cockpit, which I begrudgingly did, only to find that it too could not update the firmware. While I had hoped that Cockpit would download the firmware and upload it to the device itself, it would appear that all it does is manipulate the device API to trigger a self-firmware update – which as we saw, times out. So unless you have no access to the web UI, feel free to skip this app as it is pointless in this scenario.

Manual Installation

I downloaded the latest firmware (5.8.5 as of writing) from the Devolo support website. On attempting to manually upload the file, the update process failed and from looking at the HTTP response I could see that it was complaining that it required version 5.3.4 before it could update to 5.8.5. Automatic updates were a no-go.

The Fix

I phoned Devolo, who were no help at all on the phone and told me to email in. Which I did, suggesting that they should put all of the intermediate firmware on their website while also asking to be sent the necessary files.

They replied from Germany 3 days later with links to the files. No comment was made about putting the intermediate firmware onto the website though and – as of writing – only 5.8.5 is showing. Presumably, they have no intention of doing this (which is silly as a support call/ticket is a cost). So for posterity and for anyone else who needs them, the intermediate firmware links are:

5.2.1
https://discovery.devolo.com/index.php/s/xaq4Kax7GaRiacz/download?path=%2FdLAN1200_WiFi_ac&files=delos_dlan-1200-ac_5.2.1_2019-02-19.bin.dvl
Note: This changes to a newer and better UI from that of 2.2.0.

5.3.4
https://discovery.devolo.com/index.php/s/xaq4Kax7GaRiacz/download?path=%2FdLAN1200_WiFi_ac&files=delos_dlan-1200-ac_5.3.3_2019-09-23.bin.dvl

5.6.1
https://discovery.devolo.com/index.php/s/xaq4Kax7GaRiacz/download?path=%2FdLAN1200_WiFi_ac&files=delos_dlan-1200-ac_5.6.1_2020-10-23.bin.dvl

5.8.5
https://discovery.devolo.com/index.php/s/xaq4Kax7GaRiacz/download?path=%2FdLAN1200_WiFi_ac&files=delos_dlan-1200-ac_6.0.1_2023-09-06.bin

6.0.1 (which is newer than the one showing on the support website)
https://discovery.devolo.com/index.php/s/xaq4Kax7GaRiacz/download?path=%2FdLAN1200_WiFi_ac&files=delos_dlan-1200-ac_6.0.1_2023-09-06.bin
Note: This changes the UI once again.

I have attempted to submitted them all to the WayBackMachine, so if in the future they do not work, hopefully they managed to get the archived.

Amusingly, if you navigate to:
https://discovery.devolo.com/index.php/s/xaq4Kax7GaRiacz/download?path=%2FdLAN1200_WiFi_ac
It will download a zip file with every firmware release archived inside it apart from 2.2.0!
Note: This may work for other devices if you can deduce the correct path value.

Installation

I installed the firmware files all in correct order, however there was one “gotcha” with upgrading from 2.2.0 to 5.2.1.

Devolo Firmware Update from 2.2.0 Complete

After the update, the Devolo’s web server security switches to a HTTPS implementation running on TLS 1.1. In 2024, all modern web browsers have disabled out of box support from TLS versions lower than 1.2. Consequently, it was not possible to load the web interface to continue updating the firmware.

The fix, in Mozilla Firefox is:

  1. Open a new tab
  2. Paste the following into the address bar:
    about:config
  3. Accept any warnings/cautions offered
  4. In the search box at the top search for:
    security.tls.version.min
  5. Edit the value “3” to read “1”
  6. Once you have finished updating the firmware to the most recent release, be sure to reverse this and set “1” back to “3”.

Once the firmware had TLS 1.2 support, there were no further difficulties in the update process. It is just a shame that I had to waste a lot of time with Cockpit, phone calls and email and then wait 4 days when logic would dictate that these should just be available on the website.