[SOLVED] How to change MAC address at every boot?

mangya · 10-18-2016, 03:10 AM

Hello All

I'm using latest Kali Linux in VirtialBox environment and want to change MAC address to random on every boot.

This is what I did:

Code:

root@kali:~# crontab -e

And added this line:

Code:

@reboot /usr/bin/macchanger -r eth0

But its not working. What am I doing wrong?

It works on commandline though..

Code:

root@kali:~# macchanger -s eth0
Current MAC:   08:00:27:dd:8b:12 (CADMUS COMPUTER SYSTEMS)
Permanent MAC: 08:00:27:dd:8b:12 (CADMUS COMPUTER SYSTEMS)

root@kali:~# macchanger -r eth0
Current MAC:   08:00:27:dd:8b:12 (CADMUS COMPUTER SYSTEMS)
Permanent MAC: 08:00:27:dd:8b:12 (CADMUS COMPUTER SYSTEMS)
New MAC:       4e:c4:2f:f4:45:77 (unknown)

root@kali:~# macchanger -s eth0
Current MAC:   4e:c4:2f:f4:45:77 (unknown)
Permanent MAC: 08:00:27:dd:8b:12 (CADMUS COMPUTER SYSTEMS)

Thanks

mpapet · 10-18-2016, 10:19 PM

I don't know about the app macchanger. ]
Work out a shell script that generates a valid(!!!) mac address.

Code:

$generate_random_mac_psuedo-code
ip link set dev interface down
ip link set dev interface address $random_mac_address
ip link set dev interface up

I like using at to wait for the OS to get booted. https://linux.die.net/man/1/at

I don't know how systemd has fubar-ed /etc/rc.local, but once upon a time, /etc/rc.local was used to run your boot scripts. Put your AT command in /etc/rc.local that triggers your random mac script.

mangya · 10-19-2016, 08:54 AM

@mpapet Thanks, but I want to use macchanger only as it have many other options. I want to know why cron job is not working. According to Archi wiki, there is another method - That too not working.

https://wiki.archlinux.org/index.php...ing#macchanger

Thanks

Jjanel · 10-19-2016, 05:10 PM

crontab -l (tho this is unlikely to show anything wrong). Works here:

Login after adding (copy&paste) your line, and reboot: (before adding, current=perm)

root@host-7-41:~# macchanger -s eth0
Permanent MAC: 00:0c:29:00:07:90 (Vmware, Inc.)
Current MAC: fc:ca:e2:6b:b7:e9 (unknown)
root@host-7-41:~# uname -a
Linux ... 3.12-kali1-amd64 #1 SMP Debian 3.12.6-2kali1 (2014-01-06) x86_64 GNU/Linux
root@host-7-41:~# w
23:01:16 up 1 min, 2 users, load average: 0.19, 0.09, 0.04
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
root pts/0 hub1-gw.domain 23:00 4.00s 0.20s 0.00s w
root@host-7-41:~#

Post your `uname -a; w`

mangya · 10-20-2016, 09:42 AM

Code:

root@kali:~# uname -a
Linux kali 4.7.0-kali1-amd64 #1 SMP Debian 4.7.5-1kali3 (2016-09-29) x86_64 GNU/Linux

root@kali:~# w
 20:07:36 up 2 min,  1 user,  load average: 0.80, 0.65, 0.27
USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT
root     tty2     :1               20:06    2:11   5.92s  0.02s /usr/lib/tracker/tracker-extract

John VV · 10-21-2016, 01:48 AM

you do know that you will need to also change the MAC of the HOST machine

this is a Virtual install of kail

or are you using a usb wireless card

mangya · 10-21-2016, 05:17 AM

Quote:

Originally Posted by John VV

you do know that you will need to also change the MAC of the HOST machine

this is a Virtual install of kail

or are you using a usb wireless card

Thanks for replying. I found out that the problem is with VirtualBox. I tried the same-thing in VMWare Player - it works.

Problem solved. Thanks.