TUN device unmanaged by NetworkManager


I’m using a NetPi 3 with resin. This device employs a dedicated Ethernet chip, which you can communicate with via SPI. I’m trying to manage the network settings via NetworkManager, however nmcli shows, that the interface cifx0 is unmanaged:

root@0399429:/mnt/boot/system-connections# nmcli d
DEVICE           TYPE      STATE        CONNECTION
wlan0            wifi      connected    resin-wifi-01
resin-dns        bridge    connected    resin-dns
supervisor0      bridge    connected    supervisor0
eth0             ethernet  unavailable  --
balena0          bridge    unmanaged    --
br-7d3725b0dad7  bridge    unmanaged    --
lo               loopback  unmanaged    --
cifx0            tun       unmanaged    --
resin-vpn        tun       unmanaged    --

This is because it’s a tun device, which is blacklisted via /etc/NetworkManager/NetworkManager.conf:


As is see, this is configured because the resin-vpn interface should not be managed by NetworkManager. So, my question is:
Can I override the conf, so that this device is explicitly managed or the resin-vpn device is explicitly unmanaged by name (interface-name:resin-vpn)?

If I use plain ip to set a static ip on the interface, it works.

The code for the creation of the cifx0 device can be found here.


Hi, we are checking this out, and discussing whether it would work being even more targeted with our blacklisting (thus only resin-vpn and not all tun devices, as you mention).

Checking out whether there’s any current workaround, though.

We’ve also opened an issue for this question in the resinOS issue tracker, where you can track the progress or leave feedback too.

It seems there not any progress on this, is there? Would very much appreciate some feedback.