C[omp]ute

From: andrew cooke <andrew@...>

Date: Wed, 15 Jun 2011 21:31:20 -0400

I've recently been interested in security again.  One consequence of this was
trying to get some handle on how useful wifi antennas (cantennas, pringles
etc) are.

(Incidentally, it turns out that you can make a cantenna by wrapping a plastic
bottle in foil - that makes it much easier to get something the right size)

Anyway, to connect a cantenna to a laptop, you need an aerial socket.  While
my laptop has wifi, it doesn't have an external socket.  And, just as
importantly, it has to be supported well on Linux.

After reading around, it seemed that Atheros chips are as good as anything
these days.  And a local shop had in stock (this is Chile, so you have to take
what you can find) something called a TP-Link TL-WN722N for less than 10
pounds.

So I bought one.

And it works with opensuse 11.4 out of the box, as a simple wifi card.
Unfortunately, if you try to use it with aircrack-ng you get the notorious
"channel -1" error.  The way to fix this is explained at
http://www.aircrack-ng.org/doku.php?id=compat-wireless - follow the
instructions there to install new, patched drivers.  One small caveat - the
driver select script didn't work (ie after using it, my wifi was broken); but
building and installing everything did work.

Also, for the record, if you're seeing some other channel number, clean out
your settings - delete the config for wifi, place it under ifup and don't
configure anything - and then reboot.

Andrew