wlansniff setup

[Raghu]

Hi, 
 
I am using HostAP(STA)  & HostAP(AP). 
Can someone please let me know how to setup in monitoring 
mode. Basically I should be able to parse all the 802.11 
packets that are sent over the air between STA & AP. 
 
I tried the following (at both AP & STA) 
cd sniff 
make 
./wlansniff -b0 wlan0 
Unsupported arptype 0x0001 
 
I searched the mailing list and didnot find any matches. 
I think I am missing some basic setup. 
Can someone please point me in the right direction. 
 
-Raghu