no! Don't destroy the loopback interface configuration!

Glad you posted. I assume you mean removing 'lo' from the auto line destroys the loopback interface, even with 'loopback' in the iface line.

@SpongeBOB: forget my previous post.

Use "man interfaces"

EDIT. Btw the kernel will install an adapter for the wireless card if it has the software to do so. You may use "rfkill" to software-block the adapter, and then no networking will be configured for it. However, you will need that "rfkill" to happen early on, so will probably need to add it into initrd's init scripts. And that is a second cloud of knowledge to gain, perhaps starting with "man initramfs-tools".

I've set ifdown wlan0 into /etc/rc.local but...

My error. What follows 'iface' in the interfaces file declares the interfaces for the system. The interfaces file is what ifup/down uses when invoked. My suggestion didn't work because wlan0 isn't in the interfaces file. Assuming you tried ifconfig wlan0 down in rc.local, it may have failed for the same reason.

New suggestion:
Re-edit any changes you made and return them to system defaults.
Disable (for now) the init script you created.

What follows 'auto' in the interfaces file identifies the interface to be brought up at boot. 'lo' is like a virtual loopback device to access your local network.

Edit /etc/network/interfaces from this:

auto lo
iface lo inet loopback

to this:

auto wlan0
iface wlan0 inet loopback

This interfaces edit tells the system to enable wlan0 at boot. The 'switch' to disable wlan0 is rc.local. After the interfaces edit, test again with ifdown wlan0 or /etc/init.d/networking stop in rc.local.

I don't know if adding dhcp to the iface line will help or hinder a wireless interface. Maybe someone who knows can help?

/etc/default/networking ... CONFIGURE_INTERFACES=yes is commented out

Thank you Cheyenne, Should I  un comment it ? in order for ifconfig or ifdownto work at boot ?

-

Thanks fanderal

I've set ifdown wlan0 into /etc/rc.local but i got ~

it's weird because when i use ifconfig wlan0 down it's not generating an error, it's just not applied...

no ideas, I didn't touch for sure. anyway I'll try now with a stock devuan4 install to see what it does.

edit: with a fresh install, it trow the same error.

Is there a reason your /etc/network/interfaces doesn't include wlan0 and/or dhcp?

My interfaces file:
auto eth1
iface eth1 inet dhcp

As I said, on 2 of 3 laptops we have, it's the F12 key, below the little f12 designation there's a little symbol of an antenna, and the key has an embedded LED that lights up white when wi-fi is on, and orange when it is not. And whatever you chose in the last session persists to the next.

I've just tried in /etc/init.d/networking

EXCLUDE_INTERFACES=wlan0

but it's not working... the NIC is still up...

same with /etc/rc.local

ifconfig wlan0 down

:'(

@fanderal
Thanks, I believe you meant: /etc/network/interfaces

in that file I got (I didn't modify it)

auto lo
iface lo inet loopback

indeed I see in /etc/init.d/networking

CONFIGURE_INTERFACES=yes
EXCLUDE_INTERFACES=

If I set CONFIGURE_INTERFACES to no I assum it will affect all the interface
Maybe I can use just EXCLUDE_INTERFACES ? EXCLUDE_INTERFACES=wlan0 ?

If no laptop switch (fine suggestion greenjeans!), try setting your init script to load last. Another option is /etc/rc.local. Any cmds there are executed after all the normal system services are started and before login.

If you right click on the Network Manager icon in the tray, there is an option to enable wi-fi if not running, and disable if running.

Left-clicking that icon confirms also that wi-fi is disabled.

This all persists through re-boots, easy-peasy. Hope this helps!

I would like to disable a NIC a boot.

I've created an init script

#!/bin/sh
### BEGIN INIT INFO
# Provides:          disable_WiFi
# Required-Start:    $network $local_fs
# Required-Stop:     $network $local_fs
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Disable WiFi and BlueTooth
### END INIT INFO

case "$1" in
  start)
    echo "Disabling WiFi & BlueTooth"
    ifconfig wlan0 down
    ;;
  stop)
    echo "WiBT will not be reactived"
    ;;
  *)
    echo "Usage: $0 {start|stop}"
    exit 1
esac

exit 0

But after reboot and login ifconfig still show the interface :'(

Any ideas ?

Thanks.