Multiple SSID hostapd centos 6.4

[Frank Posito]

Hello,

I am trying to setup mutiple SSID with the goal of having VLAN tagging
on each SSID

I am using hostapd v2.0 on Centos6.4
The chipset is Atheros AR9271 (WNA1100)



My wireless MAC address is  20:E5:2A:E8:DB:77 and i changed it to
02:E5:2A:E8:DB:30

I tried to follow
http://wiki.stocksy.co.uk/wiki/Multiple_SSIDs_with_hostapd (even if
ti's for Ubuntu)

To keep it simple for now. This is my configuration file
----
interface=wlan0
bssid=02:E5:2A:E8:DB:30
driver=nl80211

ssid=ssid1
channel=1

bss=wlan0_0
ssid=ssid2

bss=wlan0_1
ssid=ssid3

bss=wlan0_2
ssid=ssid4
----

The problem seems to appear when it's trying to create wlan0_0

Could not set interface wlan0_0 flags (UP): Device or resource busy
nl80211: Remove interface ifindex=16
Failed to add BSS (BSSID=02:e5:2a:e8:db:31)
wlan0: Unable to setup interface.
wlan0: Flushing old station entries
wlan0: Deauthenticate all stations
nl80211: CMD_FRAME freq=2412 wait=0 no_cck=0 no_ack=0 offchanok=0
nl80211: Frame TX command accepted; cookie 0xffff8800372d1180


Could you give me a hint on the problem ?

Thanks,
Frank