wlan0 doesn't show up

tris_halo · 08-08-2013, 11:01 AM

- I'm using Samsung galaxy s2 (ROM 4.3). when i use command:

Code:

netcfg

- This command shows all the network cards of the device. But I can't find "wlan0". I use the command:

Code:

ifconfig wlan0 up

- The output shows that the interface doesn't exist.

-Until I turn on the wifi. The output shows "wlan0" with assigned IP, but when the wifi function turns off, "wlan0" disappears. My other device Samsung galaxy s1 (ROM 4.2.2) shows "wlan0" even if wifi function turns off.

Code:

wlan0    DOWN  0.0.0.0/0   0x00001002 00:26:37:63:d8:ab

Can you show me how to turn it on. Thanks alot

rtmistler · 08-08-2013, 02:15 PM

When you turn off the WIFI it may power it off and therefore the interface will not show up. Different manufacturers and different systems or releases may choose to not power the peripheral down. In this case since 4.2.2 still shows the WIFI even though it was disabled seems to be a bug which they resolved in 4.3 to manage battery power.

tris_halo · 08-09-2013, 03:01 AM

Quote:

Originally Posted by rtmistler

When you turn off the WIFI it may power it off and therefore the interface will not show up. Different manufacturers and different systems or releases may choose to not power the peripheral down. In this case since 4.2.2 still shows the WIFI even though it was disabled seems to be a bug which they resolved in 4.3 to manage battery power.

Thanks for your reply. Right now i really need it to show up. Is there anyway I can add "wlan0" interface ?

rtmistler · 08-09-2013, 07:36 AM

The way you asked your question initially inferred that wlan0 shows up when you have it "on" and doesn't show up when you have it "off", but that this behavior was not consistent with a former version.

If that conjecture is correct, is the reason for your question related to a script or something which is expecting to see wlan0? Because if so there are script or program ways to test for the presence of that interface first before doing other actions.

schneidz · 08-09-2013, 11:07 AM

hi, i have an sph-d710 running unnamed-rom v2.0.1. when wifi is on it lists eth0 but when it is off it only shows the device uwbr0. i tried running ifconfig eth0 up (after su -) but i get the error 'no such device'

i just tried running ifconfig eth0 down while connected to wifi. i didnt get an error but on a subsequent ifconfig it still lists the eth0 device with an ip address (meaning the previous command had no effect).