ifdown: interface wlp2s0 não configurada

Question

Estou tentando configurar a conexão WiFi com meu Ubuntu 16.10:

[] status do dispositivo nmcli

DEVICE = enp3s0 ; TYPE = ethernet ; STATE = unavailable ; CONNECTION = --
DEVICE = lo ; TYPE = loopback ; STATE = unmanaged ; CONNECTION = --
DEVICE = wlp2s0 ; TYPE = wifi ; STATE = unmanaged ; CONNECTION = --

Eu entendo que minha interface WiFi se chama 'wlp2s0' e a Ethernet 'enp3s0', certo?

[] sudo vi / etc / network / interfaces

auto wlp2s0

iface lo inet loopback
iface enp3s0 inet dhcp

allow-hotplug wlp2s0
iface wlp2s0 inet static
address 192.168.1.150
netmask 255.255.255.0
gateway 192.168.1.1
network 192.168.1.0
broadcast 192.168.1.255
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp

[] sudo /etc/wpa_supplicant/wpa_supplicant.conf

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
network={
    ssid="name_of_the_network"
    psk="my_wifi_password"
}

No entanto

[] sudo ifdown wlp2s0

ifdown: interface wlp2s0 not configured

[] sudo ifconfig

O que estou fazendo de errado? Muito obrigado