Can't connect to WiFi if setting MAC address, RTNETLINK answers: Device or resource busy

[Boris Gjenero]

If my /etc/network/interfaces settings for wlan0 include a "hwaddress ether" line, then running ifup for that interface fails at the very end, after successfully authenticating with the access point. Here is what happens:

systemd[1]: Started ifup for wlan0.
wpa_supplicant[765]: Successfully initialized wpa_supplicant
sh[737]: RTNETLINK answers: Device or resource busy
sh[737]: Failed to bring up wlan0.
systemd[1]: <email address hidden>: Main process exited, code=exited, status=1/FAILURE
wpa_supplicant[791]: nl80211: deinit ifname=wlan0 disabled_11b_rates=0

Furthermore, this kind of failure leaves a mess somehow, and subsequent attempts to connect lead to "RTNETLINK answers: File exists".

ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: ifupdown 0.8.13ubuntu3
ProcVersionSignature: Ubuntu 4.8.0-28.30-generic 4.8.6
Uname: Linux 4.8.0-28-generic x86_64
ApportVersion: 2.20.3-0ubuntu8
Architecture: amd64
CurrentDesktop: XFCE
Date: Tue Dec 6 07:48:55 2016
InstallationDate: Installed on 2012-01-19 (1783 days ago)
InstallationMedia: Xubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
SourcePackage: ifupdown
UpgradeStatus: Upgraded to yakkety on 2016-10-13 (53 days ago)

[Boris Gjenero (boris-gjenero)]

This seems to be an old bug, which is also mentioned elsewhere:
https://unix.stackexchange.com/questions/26126/spoofed-mac-address-ignored-by-wpa-supplicant
https://bugs.launchpad.net/neutron/+bug/1193972

Another symptom of this bug is probably inability to connect if you need the changed MAC address to successfully authenticate.

As a workaround, use:
    pre-up ifconfig wlan0 hw ether xx:xx:xx:xx:xx:xx
Instead of:
    hwaddress ether xx:xx:xx:xx:xx:xx

[dino99 (9d9)]

This is an unsupported release now. Please think to install the next LTS 'Bionic 18.04'

http://cdimage.ubuntu.com/ubuntu-next/daily-live/current/
https://www.omgubuntu.co.uk/2018/02/ubuntu-18-04-minimal-install-option