Using iw to add a virtual wireless interface, getting the error "No such device (-19)"

Question

I am trying to add a virtual wireless interface to my debian squeeze system using iw.

The output of iw list is shown below:

root@alix:~# iw list
Wiphy phy0

I am using the command:

iw dev phy0 interface add wlan1 type station

to add the virtual interface wlan1 however this gives me the error:

command failed: No such device (-19)

If I use the command:

iw dev wlan0 interface add wlan1 type station

it passes fine however if I try use both wlan0 and wlan1 I get an error saying neither are unique and so that doesn't work for me.

Anyone any ideas what could be causing this? Thanks

Answer 1

About the first error you get ("command failed: No such device (-19)"): You can either use

iw phy phy0 interface add <name> type <type>

or

iw dev wlan0 interface add <name> type <type>

As long as the physical names and the device names don't clash, you can also omit the phy/dev keywords and simply use

iw phy0 interface add <name> type <type>

---

About using both interfaces at the same time and the message about them not being unique:
This is probably because they both use the same MAC address. You can try to change the MAC address of the new interface before activating it.

ip link set dev <dev-name> address <new-mac-address>

---

A word about your interface modes:
My iw command (v3.4) says

Valid interface types are: managed, ibss, monitor, mesh, wds.

Not sure what "station" will do.

Also, if you're trying to operate the two interfaces in different modes, make sure your wlan card supports this:

iw list
[...]
Supported interface modes:
     * IBSS
     * managed
     * AP
     * AP/VLAN
     * WDS
     * monitor
     * mesh point
software interface modes (can always be added):
     * AP/VLAN
     * monitor
interface combinations are not supported

Notice the last line.