Comment 2 for bug 1638842

Hi, I believe I have the same issue, however there's differences that you installed Ubuntu 16.10 using chroot, while I installed Ubuntu 16.10 using netboot(and then tasksel ubuntu-desktop), here are the investigation results:

## Possible Cause ##
The problem seems to be lies on the new override config introduced in 16.10:

```
  * debian/10-globally-managed-devices.conf: ship a default config to
    explicitly unmanage anything that is not wifi or wwan: we definitely want
    NM to manage wifi and mobile data; and probably don't want it to touch
    wired in many cases.
```

which is installed at /usr/lib/NetworkManager/conf.d/10-globally-managed-devices.conf , with the following content:

```
[keyfile]
unmanaged-devices=*,except:type:wifi,except:type:wwan
```

that unmanages all network interfaces except wifi and wwan, thus bluetooth interface in your case and ethernet case in my case are all unmanaged by default.

According to the future changelog by Martin Pitt:

```
  * network-manager.postinst: Don't create
    /etc/NetworkManager/conf.d/10-globally-managed-devices.conf override on
    new installations. We don't want NM to manage non-wifi/wwan on
    servers/cloud instances, and for desktops live-build now installs a
    netplan policy snippet to let NM handle all devices.
```

This is designed to not let NM manage those interfaces except in a desktop edition(possibly because servers normally uses the ifupdown mechanism to manage networking), what I'm confused is:

* Why there's the need to do so when ifupdown NM plugin already provides the ability to unmanages the network interfaces that have settings in /etc/network/interfaces?
* Why the config still working after user installs *ubuntu-desktop, rendering those network-interfaces unmanaged even when it is clearly not for server/cloud usage?

## Workaround ##
Remove /etc/NetworkManager/conf.d/10-globally-managed-devices.conf, it works(TM)