enabling IAPP interface gives error.

[Ajeet Nankani]

when i enable IAPP option in hostapd
iapp_interface=eth0
it gives following error on starting hostapd.

setsockopt[UDP,IP_ADD_MEMBERSHIP]: No such device
IEEE 802.11F (IAPP) initialization failed.
rmdir [ctrl_interface]: No such file or directory.

I have enabaled eth0 interface and have assigned IP address to it.
I am using 0.3.7 hostapd and 1.8.0 firmware. hostapd is working fine
without enabling IAPP

what could be wrong here?

-ajeet.