On Monday 23 May 2011 22:26:49 JD wrote:
On 05/23/11 12:22, Tim Smith wrote:
> On Monday 23 May 2011 17:50:50 JD wrote:
>> On 05/23/11 09:28, Tim Smith wrote:
>>> On Monday 23 May 2011 16:36:00 Tim wrote:
>>> Not really. This is SSID, not BSSID (BSSID is usually the MAC of the
>>> AP). When you scan, you not only listen for beacons, but you (should)
>>> send probe requests. If you put an SSID into your probe request, you
>>> will get a response only from a BSS with a matching SSID, so you
>>> broadcast saying "network named 'MyHouseNetwork' please
respond" at
>>> which point you get the response from the real BSS which has the real
>>> SSID in it and not the bogus one that went in the beacons.
>>
>> Well, I have placed wpa_supplicant in full debug verbosity
>> output mode, and it's probe/scan does not seem to be aimed
>> at just my router. In fact it gets usually 3 to 5 responses
>> from which it then selects my AP.
>> The wpa_supplicant.conf has the SSID and the BSSID in the
>> configuration. So, how come the probe/scan gets more than
>> one response?
>
> Well, note I said "If" :-)
>
> If you do not place ANY SSID into the probe request, then all networks
> will respond. Depending on the configuration of a multi-SSID AP you may
> see more than one probe response from the same MAC address in this case.
> Or not. That may be up to the guy who runs the network(s) or it may be a
> hard-coded behaviour of the APs being used.
>
> See the scan_ssid parameter for wpa_supplicant for how to change
> wpa_supplicant's behaviour in this respect.
You did not show the part where I said that
my router's BSSID and the nets SSID are in
wpa_supplicant.conf.
So, I am asking how come the wpa_supplicant
is not aiming it's probe directly at that BSSID
and SSID coded in the config file? It seems to
me that it should do that.
I wrote:
> See the scan_ssid parameter for wpa_supplicant for how to
change
> wpa_supplicant's behaviour in this respect.
Seriously. wpa_supplicant won't do that unless you change that parameter.
Though of course you don't say whether that parameter is set, so you might
have it set and I didn't know that, in which case it seems like you might have
found a bug in wpa_supplicant (I'm assuming you have a sniffer trace of the
probe request off the air to verify this. Call me old-fashioned and paranoid
but I never *quite* trust a program's own debug output without independent
verification :-)
From /usr/share/doc/wpa_supplicant-0.6.8/wpa_supplicant.conf:
# scan_ssid:
# 0 = do not scan this SSID with specific Probe Request frames (default)
# 1 = scan with SSID-specific Probe Request frames (this can be used to
# find APs that do not accept broadcast SSID or use multiple SSIDs;
# this will add latency to scanning, so enable this only when
needed)
--
Tim Smith <tim(a)electronghost.co.uk>
UPDATE: Luke Skywalker is a FAILED Alliance Public Relations Exercise.