Unicast probe request vs Broadcast probe request.

[alfred steele]

Hi All,

I dugged up the 802.11-2007 specs and other forums. Could not
understand the timer mechanism associated to the unicast probe
requests.

I have a client which sends out the probe requests in the following order:

i) First timer during which it sends out broadcast Probe requests:
  TO MAC layer destination mac address as FF:FF:FF:FF:FF and 802.11
MAC BSSID as FF:FF:FF:FF:FF
ii) SEcond timer sends out broadcast probe requests:
TO MAC layer destination mac address as FF:FF:FF:FF:FF and 802.11 MAC
BSSID as the AP's BSSID
iii) AFter the AP fails to respond to (ii), it sends out UNICAST probe requests:
TO MAC layer destination mac address as AP's BSSID and 802.11 MAC
BSSID as the AP's BSSID.

Two questions:
What should be the correct sequence to send out the probe requests?
Is there a way to send out a unicast probe request ONLY through
configuration of wpa supplicant?
IS  message(ii) counted a broadcast or a unicast probe request?

Thanks,
Alfred.