Re: capturing on both interfaces simultaneously

[dragorn () durandal kismetwireless net]

On Mon, Dec 12, 2011 at 12:53:38PM -0800, Guy Harris wrote:
 
> > Will I ever see HT40+,40- in case of beacons.
>
> Probably not.
>
> > Does this field in radiotap header (if it occurs) mean the interface beacon
> > came from was having the above (equivilantly n ) support ?
>
> No.  This field indicates how the particular frame was transmitted; it does not mean that the transmitting device 
> cannot transmit in any other format.
>
> > Ok. So, there is nothing as a N beacon..
> > Only advertisements at 1,6 rate and then actual data at N speed.
>
> Right.  The beacons will generally be transmitted at low speed, so even older stations can see them.

About the only time you'll see beacons on non-basic rates is a
greenfield deployment, of which I've *never* found one in the wild
despite all the manufacturers caring about it.

Also under linux you will need to tune explicitly to CH+ or CH- to get
40mhz data packets, they will be silently ignored on just CH.  This
means you must use netlink to set the channel as siochannel can't
understand HT+ and HT-.

I don't recall offhand if you'll still see basicrate packets on CH+ or
CH- settings.

Sniffing 11n in linux is a big mess.

-m

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