OpenWrt Forum Archive

Topic: Change wifi MAC address

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Post #1
bauerj
20 Jun 2016, 20:13

Hello,

I want to change the wifi MAC address on my TL-WR841n, I tried the usual way using ifconfig:

root@OpenWrt:/# ifconfig
...
wlan1     Link encap:Ethernet  HWaddr 10:FE:ED:EB:65:C0
          inet6 addr: fe80::12fe:edff:feeb:65c0/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1317 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1953 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:260870 (254.7 KiB)  TX bytes:515115 (503.0 KiB)

root@OpenWrt:/# ifconfig wlan1 down
root@OpenWrt:/# ifconfig wlan1 hw ether 10:FE:ED:EB:66:A0
root@OpenWrt:/# ifconfig wlan1 up
root@OpenWrt:/# ifconfig
...
wlan1     Link encap:Ethernet  HWaddr 10:FE:ED:EB:66:A0
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:1328 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1985 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:263754 (257.5 KiB)  TX bytes:526934 (514.5 KiB)

All good so far, but when I start wifi:

root@OpenWrt:/# wifi
root@OpenWrt:/# ifconfig
...
wlan1     Link encap:Ethernet  HWaddr 10:FE:ED:EB:65:C0
          inet6 addr: fe80::12fe:edff:feeb:65c0/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:12 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:1056 (1.0 KiB)

The MAC-address gets changed back to the original one.

I tried to join the network manually after changing the MAC address but that didn't work either:

root@OpenWrt:/# iwconfig wlan0 essid mDjMAR1L5IsAQwG4
Error for wireless request "Set ESSID" (8B1A) :
    SET failed on device wlan0 ; Operation not supported.
root@OpenWrt:/# iw dev wlan0 connect -w mDjMAR1L5IsAQwG4
command failed: Operation not supported (-122)

I looked at what the /sbin/wifi script does, but I was unable to find out where the ubus calls are going.

What am I doing wrong? How can I spoof the MAC address for the wifi interface?

Post #2
nenekofi
20 Jun 2016, 21:30

Set it as such in your /etc/config/wireless:

uci -q set wireless.@wifi-iface[-1].macaddr=$mac_addr
Post #4
bauerj
20 Jun 2016, 22:29

Thanks nenekofi, that was suprisingly easy!

iasimov wrote:

it's a bit more complex than nenekofi solution, but it's a permanent change.

Thanks for the link, but this "half-permanent" way (e.g. it lasts through reboots) is enough for me. I don't want to risk bricking my router wink


iasimov wrote:

btw, someone know about legal aspects of change mac addr?

That's a good question, according to the wikipedia article it depends on what you do with the spoofed MAC address.

The discussion might have continued from here.