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Wireshark-users: [Wireshark-users] R: Ipw3945 monitor mode

From: "Massimo Palmeri" <mpalmeri@xxxxxx>
Date: Fri, 26 Oct 2007 14:09:59 +0200
Steve, thank you for your reply.
I agree with you, but this confirms my idea that my receiver is listening to
many channels and not only to channel 9 as I would like; I say that because
in the radiotap header I can read different channel numbers, but the frames
come always from the same AP. My goal is to force my receiver in monitor
mode to listen ONLY to one channel.
Note that I don't have this kind of problem with another wifi adapter based
on Atheros 5K chipset.

Best regards,
Massimo

-----Messaggio originale-----
Da: wireshark-users-bounces@xxxxxxxxxxxxx
[mailto:wireshark-users-bounces@xxxxxxxxxxxxx] Per conto di Stephen Fisher
Inviato: giovedì 25 ottobre 2007 18.50
A: Community support list for Wireshark
Oggetto: Re: [Wireshark-users] Ipw3945 monitor mode

On Thu, Oct 25, 2007 at 04:30:13PM +0200, Palmeri Massimo wrote:

> iwconfig eth1 mode monitor
> iwconfig eth1 channel 9

> It works, but I also see frames from other channels

802.11b/g runs in the 2.4GHz band and each channel in the is 5MHz wide. 
However, when using a channel, the signal spreads 25MHz wide covering 5
channels at once.  This means that means that channel 9 is picking up
traffic from channels 9-13.  This may be why you are seeing traffic from
other channels.


Steve

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