NetworkManager not managing additional ethernet interface

OS: balenaOS 2.38.3+rev2
device: SKX2

We have an UBlox LTE modem in our device that we have been using for a while. It appear to the system as a RNDIS ethernet interface so everything should just work out of the box. After upgrading to BalenaOS 2.38.3, that device stopped coming up on boot. NetworkManager says is not managed and trying to set it to be managed by NetworkManager results in an error saying it’s strictly unmanaged.
After searching around, I found this thread that seems to have a solution: <- comment #6 .
I confirmed that this does work but required modifications in the filesystem on the HostOS side. Is there a way to achieve the same results via DBUS or another method?


  • There are a bunch of things one can do to customize the os while booting, they can be found here. Unfortunately, we don’t have a method of mounting files from the boot partition to the path that you need (i.e. /etc/NetworkManager/conf.d/).
  • Creating an empty conf file feels like a workaround to problem rooted elsewhere. Are there any other things that you have tried that worked? Maybe we can approach this differently.
  • Also, 2.38.3 is rather old. Can you try this with the latest os version and share the results?


Can you guys update the latest available image for SKX2? 2.38.3 is the latest available I see.

I’m asking internally to see what is the update status on that device. We do have newer versions on staging ( if you want to try. You do need to create a new account account there, and there is of course no guarantees as it is still a test version.

Ok, thank you! We’ll test the latest on staging and let you know how it goes.

Hi David, does the carrier board have a serial debug interface?